Convert causal-conv1d to a Hub kernel

README.md

@@ -0,0 +1,10 @@
+---
+license: bsd-3-clause
+tags:
+  - kernel
+---
+
+## causal-conv1d
+
+Causal depthwise conv1d kernel by Tri Dao. Source: https://github.com/Dao-AILab/causal-conv1d/
+

build.toml

@@ -0,0 +1,49 @@
+[general]
+name = "causal_conv1d"
+universal = false
+
+[torch]
+src = [
+  "torch-ext/pytorch_shim.h",
+  "torch-ext/torch_binding.cpp",
+  "torch-ext/torch_binding.h"
+]
+
+[kernel.causal_conv1d]
+backend = "cuda"
+src = [
+  "causal-conv1d/causal_conv1d_bwd.cu",
+  "causal-conv1d/causal_conv1d_common.h",
+  "causal-conv1d/causal_conv1d.cpp",
+  "causal-conv1d/causal_conv1d_fwd.cu",
+  "causal-conv1d/causal_conv1d.h",
+  "causal-conv1d/causal_conv1d_update.cu",
+  "causal-conv1d/static_switch.h",
+]
+include = [ "causal-conv1d" ]
+depends = [ "torch" ]
+
+[kernel.causal_conv1d_rocm]
+backend = "rocm"
+rocm-archs = [
+    "gfx906",
+    "gfx908",
+    "gfx90a",
+    "gfx940",
+    "gfx941",
+    "gfx942",
+    "gfx1030",
+    "gfx1100",
+    "gfx1101",
+]
+src = [
+  "causal-conv1d/causal_conv1d_bwd.cu",
+  "causal-conv1d/causal_conv1d_common.h",
+  "causal-conv1d/causal_conv1d.cpp",
+  "causal-conv1d/causal_conv1d_fwd.cu",
+  "causal-conv1d/causal_conv1d.h",
+  "causal-conv1d/causal_conv1d_update.cu",
+  "causal-conv1d/static_switch.h",
+]
+include = [ "causal-conv1d" ]
+depends = [ "torch" ]

causal-conv1d/causal_conv1d.cpp

@@ -0,0 +1,486 @@
+/******************************************************************************
+ * Copyright (c) 2024, Tri Dao.
+ ******************************************************************************/
+
+#include <torch/all.h>
+#if TORCH_VERSION_MAJOR > 2 || (TORCH_VERSION_MAJOR == 2 && TORCH_VERSION_MINOR >= 6)
+#include <c10/core/DeviceGuard.h>
+#else
+#include <c10/cuda/CUDAGuard.h>
+#endif
+
+#include <c10/cuda/CUDAStream.h>
+#include <vector>
+
+#include "causal_conv1d.h"
+
+#define CHECK_SHAPE(x, ...) TORCH_CHECK(x.sizes() == torch::IntArrayRef({__VA_ARGS__}), #x " must have shape (" #__VA_ARGS__ ")")
+
+#define DISPATCH_ITYPE_FLOAT_AND_HALF_AND_BF16(ITYPE, NAME, ...)                    \
+    if (ITYPE == at::ScalarType::Half) {                                            \
+        using input_t = at::Half;                                                   \
+        __VA_ARGS__();                                                              \
+    } else if (ITYPE == at::ScalarType::BFloat16) {                                 \
+        using input_t = at::BFloat16;                                               \
+        __VA_ARGS__();                                                              \
+    } else if (ITYPE == at::ScalarType::Float)  {                                   \
+        using input_t = float;                                                      \
+        __VA_ARGS__();                                                              \
+    } else {                                                                        \
+        AT_ERROR(#NAME, " not implemented for input type '", toString(ITYPE), "'"); \
+    }
+
+#define DISPATCH_WTYPE_FLOAT_AND_HALF_AND_BF16(WTYPE, NAME, ...)                     \
+    if (WTYPE == at::ScalarType::Half) {                                             \
+        using weight_t = at::Half;                                                   \
+        __VA_ARGS__();                                                               \
+    } else if (WTYPE == at::ScalarType::BFloat16) {                                  \
+        using weight_t = at::BFloat16;                                               \
+        __VA_ARGS__();                                                               \
+    } else if (WTYPE == at::ScalarType::Float)  {                                    \
+        using weight_t = float;                                                      \
+        __VA_ARGS__();                                                               \
+    } else {                                                                         \
+        AT_ERROR(#NAME, " not implemented for weight type '", toString(WTYPE), "'"); \
+    }
+
+template<typename input_t, typename weight_t>
+void causal_conv1d_fwd_cuda(ConvParamsBase &params, cudaStream_t stream);
+template <typename input_t, typename weight_t>
+void causal_conv1d_channellast_fwd_cuda(ConvParamsBase &params, cudaStream_t stream);
+
+template<typename input_t, typename weight_t>
+void causal_conv1d_bwd_cuda(ConvParamsBwd &params, cudaStream_t stream);
+template<typename input_t, typename weight_t>
+void causal_conv1d_channellast_bwd_cuda(ConvParamsBwd &params, cudaStream_t stream);
+
+template<typename input_t, typename weight_t>
+void causal_conv1d_update_cuda(ConvParamsBase &params, cudaStream_t stream);
+
+void set_conv_params_fwd(ConvParamsBase &params,
+                         // sizes
+                         const size_t batch,
+                         const size_t dim,
+                         const size_t seqlen,
+                         const size_t width,
+                         // device pointers
+                         const at::Tensor x,
+                         const at::Tensor weight,
+                         const at::Tensor out,
+                         void* bias_ptr,
+                         bool silu_activation) {
+
+    // Reset the parameters
+    memset(&params, 0, sizeof(params));
+
+    params.batch = batch;
+    params.dim = dim;
+    params.seqlen = seqlen;
+    params.width = width;
+
+    params.silu_activation = silu_activation;
+
+    // Set the pointers and strides.
+    params.x_ptr = x.data_ptr();
+    params.weight_ptr = weight.data_ptr();
+    params.bias_ptr = bias_ptr;
+    params.out_ptr = out.data_ptr();
+    // All stride are in elements, not bytes.
+    params.x_batch_stride = x.stride(0);
+    params.x_c_stride = x.stride(1);
+    params.x_l_stride = x.stride(-1);
+    params.weight_c_stride = weight.stride(0);
+    params.weight_width_stride = weight.stride(1);
+    params.out_batch_stride = out.stride(0);
+    params.out_c_stride = out.stride(1);
+    params.out_l_stride = out.stride(-1);
+}
+
+
+void set_conv_params_bwd(ConvParamsBwd &params,
+                         // sizes
+                         const size_t batch,
+                         const size_t dim,
+                         const size_t seqlen,
+                         const size_t width,
+                         // device pointers
+                         const at::Tensor x,
+                         const at::Tensor weight,
+                         void* bias_ptr,
+                         const at::Tensor dout,
+                         const at::Tensor dx,
+                         const at::Tensor dweight,
+                         void* dbias_ptr,
+                         bool silu_activation) {
+    // Pass in "dout" instead of "out", we're not gonna use "out" at all.
+    set_conv_params_fwd(params, batch, dim, seqlen, width,
+                        x, weight, dout, bias_ptr, silu_activation);
+
+    // Set the pointers and strides.
+    params.dout_ptr = dout.data_ptr();
+    params.dx_ptr = dx.data_ptr();
+    params.dweight_ptr = dweight.data_ptr();
+    params.dbias_ptr = dbias_ptr;
+    // All stride are in elements, not bytes.
+    params.dout_batch_stride = dout.stride(0);
+    params.dout_c_stride = dout.stride(1);
+    params.dout_l_stride = dout.stride(2);
+    params.dweight_c_stride = dweight.stride(0);
+    params.dweight_width_stride = dweight.stride(1);
+    params.dx_batch_stride = dx.stride(0);
+    params.dx_c_stride = dx.stride(1);
+    params.dx_l_stride = dx.stride(2);
+}
+
+void
+causal_conv1d_fwd(const at::Tensor &x,
+                  const at::Tensor &weight,
+                  const c10::optional<at::Tensor> &bias_,
+                  const c10::optional<at::Tensor> &seq_idx_,
+                  const c10::optional<at::Tensor> &initial_states_,
+                  at::Tensor &out,
+                  c10::optional<at::Tensor> &final_states_out_,
+                  bool silu_activation) {
+    auto input_type = x.scalar_type();
+    auto weight_type = weight.scalar_type();
+    TORCH_CHECK(input_type == at::ScalarType::Float || input_type == at::ScalarType::Half || input_type == at::ScalarType::BFloat16);
+    TORCH_CHECK(weight_type == at::ScalarType::Float || weight_type == at::ScalarType::Half || weight_type == at::ScalarType::BFloat16);
+
+    TORCH_CHECK(x.is_cuda());
+    TORCH_CHECK(weight.is_cuda());
+
+    const auto sizes = x.sizes();
+    const int batch_size = sizes[0];
+    const int dim = sizes[1];
+    const int seqlen = sizes[2];
+    const int width = weight.size(-1);
+
+    CHECK_SHAPE(x, batch_size, dim, seqlen);
+    CHECK_SHAPE(weight, dim, width);
+
+    TORCH_CHECK(x.stride(2) == 1 || x.stride(1) == 1);
+    const bool is_channel_last = x.stride(1) == 1 && x.stride(2) > 1;
+
+    if (is_channel_last) {
+        TORCH_CHECK(dim % 8 == 0, "causal_conv1d only supports channel dimension divisible by 8 for now");
+        TORCH_CHECK(x.stride(2) % 8 == 0 and x.stride(0) % 8 == 0, "causal_conv1d with channel last layout requires strides (x.stride(0) and x.stride(2)) to be multiples of 8");
+    }
+    TORCH_CHECK(width >= 2 && width <= 4, "causal_conv1d only supports width between 2 and 4");
+
+    if (bias_.has_value()) {
+        auto bias = bias_.value();
+        TORCH_CHECK(bias.scalar_type() == weight_type);
+        TORCH_CHECK(bias.is_cuda());
+        TORCH_CHECK(bias.stride(-1) == 1);
+        CHECK_SHAPE(bias, dim);
+    }
+
+    if (seq_idx_.has_value()) {
+        TORCH_CHECK(is_channel_last, "seq_idx is only supported for channel last layout");
+        auto seq_idx = seq_idx_.value();
+        TORCH_CHECK(seq_idx.scalar_type() == torch::kInt32);
+        TORCH_CHECK(seq_idx.is_cuda());
+        TORCH_CHECK(seq_idx.is_contiguous());
+        CHECK_SHAPE(seq_idx, batch_size, seqlen);
+    }
+
+    ConvParamsBase params;
+    set_conv_params_fwd(params, batch_size, dim, seqlen, width, x, weight, out,
+                        bias_.has_value() ? bias_.value().data_ptr() : nullptr,
+                        silu_activation);
+
+    if (seq_idx_.has_value()) {
+        params.seq_idx_ptr = seq_idx_.value().data_ptr();
+    } else {
+        params.seq_idx_ptr = nullptr;
+    }
+
+    if (initial_states_.has_value()) {
+        TORCH_CHECK(is_channel_last, "initial_states is only supported for channel last layout");
+        auto initial_states = initial_states_.value();
+        TORCH_CHECK(initial_states.scalar_type() == input_type);
+        TORCH_CHECK(initial_states.is_cuda());
+        CHECK_SHAPE(initial_states, batch_size, dim, width - 1);
+        TORCH_CHECK(initial_states.stride(1) == 1);
+        params.initial_states_ptr = initial_states.data_ptr();
+        params.initial_states_batch_stride = initial_states.stride(0);
+        params.initial_states_c_stride = initial_states.stride(1);
+        params.initial_states_l_stride = initial_states.stride(2);
+    } else {
+        params.initial_states_ptr = nullptr;
+    }
+
+    if (final_states_out_.has_value()) {
+        TORCH_CHECK(is_channel_last, "final_states is only supported for channel last layout");
+        auto final_states = final_states_out_.value();
+        TORCH_CHECK(final_states.scalar_type() == input_type);
+        TORCH_CHECK(final_states.is_cuda());
+        CHECK_SHAPE(final_states, batch_size, dim, width - 1);
+        TORCH_CHECK(final_states.stride(1) == 1);
+        params.final_states_ptr = final_states.data_ptr();
+        params.final_states_batch_stride = final_states.stride(0);
+        params.final_states_c_stride = final_states.stride(1);
+        params.final_states_l_stride = final_states.stride(2);
+    } else {
+        params.final_states_ptr = nullptr;
+    }
+
+    // Otherwise the kernel will be launched from cuda:0 device
+#if TORCH_VERSION_MAJOR > 2 || (TORCH_VERSION_MAJOR == 2 && TORCH_VERSION_MINOR >= 6)
+    c10::DeviceGuard device_guard(x.device());
+#else
+    at::cuda::CUDAGuard device_guard{x.device()};
+#endif
+    auto stream = at::cuda::getCurrentCUDAStream().stream();
+    DISPATCH_ITYPE_FLOAT_AND_HALF_AND_BF16(x.scalar_type(), "causal_conv1d_fwd", [&] {
+        DISPATCH_WTYPE_FLOAT_AND_HALF_AND_BF16(weight.scalar_type(), "causal_conv1d_fwd", [&] {
+            if (!is_channel_last) {
+                causal_conv1d_fwd_cuda<input_t, weight_t>(params, stream);
+            } else {
+                causal_conv1d_channellast_fwd_cuda<input_t, weight_t>(params, stream);
+            }
+        });
+    });
+}
+
+void
+causal_conv1d_bwd(const at::Tensor &x,
+                  const at::Tensor &weight,
+                  const c10::optional<at::Tensor> &bias_,
+                  at::Tensor &dout,
+                  const c10::optional<at::Tensor> &seq_idx_,
+                  const c10::optional<at::Tensor> &initial_states_,
+                  const c10::optional<at::Tensor> &dfinal_states_,
+                  at::Tensor &dx,
+                  at::Tensor &dweight,
+                  c10::optional<at::Tensor> &dbias_,
+                  c10::optional<at::Tensor> &dinitial_states_,
+                  bool silu_activation) {
+    auto input_type = x.scalar_type();
+    auto weight_type = weight.scalar_type();
+    TORCH_CHECK(input_type == at::ScalarType::Float || input_type == at::ScalarType::Half || input_type == at::ScalarType::BFloat16);
+    TORCH_CHECK(weight_type == at::ScalarType::Float || weight_type == at::ScalarType::Half || weight_type == at::ScalarType::BFloat16);
+
+    TORCH_CHECK(x.is_cuda());
+    TORCH_CHECK(weight.is_cuda());
+    TORCH_CHECK(dout.is_cuda());
+    TORCH_CHECK(bias_.has_value() == dbias_.has_value());
+
+    const auto sizes = x.sizes();
+    const int batch_size = sizes[0];
+    const int dim = sizes[1];
+    const int seqlen = sizes[2];
+    const int width = weight.size(-1);
+
+    TORCH_CHECK(width >= 2 && width <= 4, "causal_conv1d only supports width between 2 and 4");
+
+    CHECK_SHAPE(x, batch_size, dim, seqlen);
+    CHECK_SHAPE(weight, dim, width);
+    CHECK_SHAPE(dout, batch_size, dim, seqlen);
+
+    TORCH_CHECK(x.stride(2) == 1 || x.stride(1) == 1);
+    const bool is_channel_last = x.stride(1) == 1 && x.stride(2) > 1;
+    if (!is_channel_last && dout.stride(2) != 1) { dout = dout.contiguous(); }
+    if (is_channel_last && dout.stride(1) != 1) { dout = dout.transpose(-1, -2).contiguous().transpose(-1, -2); }
+
+    if (is_channel_last) {
+        TORCH_CHECK(dim % 8 == 0, "causal_conv1d only supports channel dimension divisible by 8 for now");
+        TORCH_CHECK(x.stride(2) % 8 == 0 and x.stride(0) % 8 == 0, "causal_conv1d with channel last layout requires strides (x.stride(0) and x.stride(2)) to be multiples of 8");
+        TORCH_CHECK(dout.stride(2) % 8 == 0 and dout.stride(0) % 8 == 0, "causal_conv1d with channel last layout requires strides (dout.stride(0) and dout.stride(2)) to be multiples of 8");
+    }
+
+    if (bias_.has_value()) {
+        auto bias = bias_.value();
+        TORCH_CHECK(bias.scalar_type() == weight_type);
+        TORCH_CHECK(bias.is_cuda());
+        TORCH_CHECK(bias.stride(-1) == 1);
+        CHECK_SHAPE(bias, dim);
+    }
+
+    if (seq_idx_.has_value()) {
+        TORCH_CHECK(is_channel_last, "seq_idx only supported for channel last layout");
+        auto seq_idx = seq_idx_.value();
+        TORCH_CHECK(seq_idx.scalar_type() == torch::kInt32);
+        TORCH_CHECK(seq_idx.is_cuda());
+        TORCH_CHECK(seq_idx.is_contiguous());
+        CHECK_SHAPE(seq_idx, batch_size, seqlen);
+    }
+
+    TORCH_CHECK(dx.scalar_type() == input_type);
+    TORCH_CHECK(dx.is_cuda());
+    CHECK_SHAPE(dx, batch_size, dim, seqlen);
+    if (!is_channel_last) { TORCH_CHECK(dx.stride(2) == 1); }
+    if (is_channel_last) { TORCH_CHECK(dx.stride(1) == 1); }
+
+    // Otherwise the kernel will be launched from cuda:0 device
+#if TORCH_VERSION_MAJOR > 2 || (TORCH_VERSION_MAJOR == 2 && TORCH_VERSION_MINOR >= 6)
+    c10::Device device = x.device();
+    c10::DeviceGuard device_guard(device);
+#else
+    at::cuda::CUDAGuard device_guard{x.device()};
+#endif
+    ConvParamsBwd params;
+    set_conv_params_bwd(params, batch_size, dim, seqlen, width,
+                        x, weight, bias_.has_value() ? bias_.value().data_ptr() : nullptr,
+                        dout, dx, dweight, bias_.has_value() ? dbias_.value().data_ptr() : nullptr,
+                        silu_activation);
+
+    if (seq_idx_.has_value()) {
+        params.seq_idx_ptr = seq_idx_.value().data_ptr();
+    } else {
+        params.seq_idx_ptr = nullptr;
+    }
+
+    if (initial_states_.has_value()) {
+        TORCH_CHECK(is_channel_last, "initial_states is only supported for channel last layout");
+        auto initial_states = initial_states_.value();
+        TORCH_CHECK(initial_states.scalar_type() == input_type);
+        TORCH_CHECK(initial_states.is_cuda());
+        CHECK_SHAPE(initial_states, batch_size, dim, width - 1);
+        TORCH_CHECK(initial_states.stride(1) == 1);
+        params.initial_states_ptr = initial_states.data_ptr();
+        params.initial_states_batch_stride = initial_states.stride(0);
+        params.initial_states_c_stride = initial_states.stride(1);
+        params.initial_states_l_stride = initial_states.stride(2);
+    } else {
+        params.initial_states_ptr = nullptr;
+    }
+
+    if (dfinal_states_.has_value()) {
+        TORCH_CHECK(is_channel_last, "dfinal_states is only supported for channel last layout");
+        auto dfinal_states = dfinal_states_.value();
+        TORCH_CHECK(dfinal_states.scalar_type() == input_type);
+        TORCH_CHECK(dfinal_states.is_cuda());
+        CHECK_SHAPE(dfinal_states, batch_size, dim, width - 1);
+        params.dfinal_states_ptr = dfinal_states.data_ptr();
+        params.dfinal_states_batch_stride = dfinal_states.stride(0);
+        params.dfinal_states_c_stride = dfinal_states.stride(1);
+        params.dfinal_states_l_stride = dfinal_states.stride(2);
+    } else {
+        params.dfinal_states_ptr = nullptr;
+    }
+
+    if (dinitial_states_.has_value()) {
+        at::Tensor dinitial_states = dinitial_states_.value();
+        TORCH_CHECK(dinitial_states.stride(1) == 1);
+        params.dinitial_states_ptr = dinitial_states.data_ptr();
+        params.dinitial_states_batch_stride = dinitial_states.stride(0);
+        params.dinitial_states_c_stride = dinitial_states.stride(1);
+        params.dinitial_states_l_stride = dinitial_states.stride(2);
+    } else {
+        params.dinitial_states_ptr = nullptr;
+    }
+
+    auto stream = at::cuda::getCurrentCUDAStream().stream();
+    DISPATCH_ITYPE_FLOAT_AND_HALF_AND_BF16(x.scalar_type(), "causal_conv1d_bwd", [&] {
+        DISPATCH_WTYPE_FLOAT_AND_HALF_AND_BF16(weight.scalar_type(), "causal_conv1d_bwd", [&] {
+            if (!is_channel_last) {
+                causal_conv1d_bwd_cuda<input_t, weight_t>(params, stream);
+            } else {
+                causal_conv1d_channellast_bwd_cuda<input_t, weight_t>(params, stream);
+            }
+        });
+    });
+}
+
+void
+causal_conv1d_update(const at::Tensor &x,
+                     const at::Tensor &conv_state,
+                     const at::Tensor &weight,
+                     const c10::optional<at::Tensor> &bias_,
+                     at::Tensor &out,
+                     bool silu_activation,
+                     const c10::optional<at::Tensor> &cache_seqlens_,
+                     const c10::optional<at::Tensor> &conv_state_indices_
+                     ) {
+    auto input_type = x.scalar_type();
+    auto weight_type = weight.scalar_type();
+    TORCH_CHECK(input_type == at::ScalarType::Float || input_type == at::ScalarType::Half || input_type == at::ScalarType::BFloat16);
+    TORCH_CHECK(weight_type == at::ScalarType::Float || weight_type == at::ScalarType::Half || weight_type == at::ScalarType::BFloat16);
+    TORCH_CHECK(conv_state.scalar_type() == input_type);
+
+    TORCH_CHECK(x.is_cuda());
+    TORCH_CHECK(conv_state.is_cuda());
+    TORCH_CHECK(weight.is_cuda());
+
+    const auto sizes = x.sizes();
+    const int batch_size = sizes[0];
+    const int dim = sizes[1];
+    const int seqlen = sizes[2];
+    const int width = weight.size(-1);
+    const int conv_state_len = conv_state.size(2);
+    TORCH_CHECK(conv_state_len >= width - 1);
+
+    CHECK_SHAPE(x, batch_size, dim, seqlen);
+    CHECK_SHAPE(weight, dim, width);
+
+    TORCH_CHECK(width >= 2 && width <= 4, "causal_conv1d only supports width between 2 and 4");
+
+    if (bias_.has_value()) {
+        auto bias = bias_.value();
+        TORCH_CHECK(bias.scalar_type() == weight_type);
+        TORCH_CHECK(bias.is_cuda());
+        TORCH_CHECK(bias.stride(-1) == 1);
+        CHECK_SHAPE(bias, dim);
+    }
+
+    ConvParamsBase params;
+    set_conv_params_fwd(params, batch_size, dim, seqlen, width, x, weight, out,
+                        bias_.has_value() ? bias_.value().data_ptr() : nullptr,
+                        silu_activation);
+    params.conv_state_ptr = conv_state.data_ptr();
+    params.conv_state_len = conv_state_len;
+    // All stride are in elements, not bytes.
+    params.conv_state_batch_stride = conv_state.stride(0);
+    params.conv_state_c_stride = conv_state.stride(1);
+    params.conv_state_l_stride = conv_state.stride(2);
+
+    if (conv_state_indices_.has_value()) {
+        auto conv_state_indices = conv_state_indices_.value();
+        TORCH_CHECK(conv_state_indices.scalar_type() == torch::kInt32)
+        TORCH_CHECK(conv_state_indices.is_cuda());
+        TORCH_CHECK(conv_state_indices.stride(0) == 1)
+        CHECK_SHAPE(conv_state_indices, batch_size);
+
+        int conv_state_entries = conv_state.size(0);
+        CHECK_SHAPE(conv_state, conv_state_entries, dim, conv_state_len);
+
+        params.conv_state_indices_ptr = conv_state_indices.data_ptr<int32_t>();
+    } else {
+        CHECK_SHAPE(conv_state, batch_size, dim, conv_state_len);
+        params.conv_state_indices_ptr = nullptr;
+    }
+
+    if (cache_seqlens_.has_value()) {
+        auto cache_seqlens = cache_seqlens_.value();
+        TORCH_CHECK(cache_seqlens.scalar_type() == torch::kInt32);
+        TORCH_CHECK(cache_seqlens.is_cuda());
+        TORCH_CHECK(cache_seqlens.stride(-1) == 1);
+        CHECK_SHAPE(cache_seqlens, batch_size);
+        params.cache_seqlens = cache_seqlens.data_ptr<int32_t>();
+    } else {
+        params.cache_seqlens = nullptr;
+    }
+
+    // Otherwise the kernel will be launched from cuda:0 device
+#if TORCH_VERSION_MAJOR > 2 || (TORCH_VERSION_MAJOR == 2 && TORCH_VERSION_MINOR >= 6)
+    c10::Device device = x.device();
+    c10::DeviceGuard device_guard(device);
+#else
+    at::cuda::CUDAGuard device_guard{x.device()};
+#endif
+    auto stream = at::cuda::getCurrentCUDAStream().stream();
+    DISPATCH_ITYPE_FLOAT_AND_HALF_AND_BF16(x.scalar_type(), "causal_conv1d_update", [&] {
+        DISPATCH_WTYPE_FLOAT_AND_HALF_AND_BF16(weight.scalar_type(), "causal_conv1d_update", [&] {
+            causal_conv1d_update_cuda<input_t, weight_t>(params, stream);
+        });
+    });
+}
+
+/*
+PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
+    m.def("causal_conv1d_fwd", &causal_conv1d_fwd, "Causal conv1d forward");
+    m.def("causal_conv1d_bwd", &causal_conv1d_bwd, "Causal conv1d backward");
+    m.def("causal_conv1d_update", &causal_conv1d_update, "Causal conv1d update");
+}
+*/

causal-conv1d/causal_conv1d.h

@@ -0,0 +1,81 @@
+/******************************************************************************
+ * Copyright (c) 2024, Tri Dao.
+ ******************************************************************************/
+
+#pragma once
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+struct ConvParamsBase {
+    using index_t = uint32_t;
+
+    int batch, dim, seqlen, width;
+    bool silu_activation;
+
+    index_t x_batch_stride;
+    index_t x_c_stride;
+    index_t x_l_stride;
+    index_t weight_c_stride;
+    index_t weight_width_stride;
+    index_t out_batch_stride;
+    index_t out_c_stride;
+    index_t out_l_stride;
+
+    int conv_state_len;
+    index_t conv_state_batch_stride;
+    index_t conv_state_c_stride;
+    index_t conv_state_l_stride;
+
+    // Common data pointers.
+    void *__restrict__ x_ptr;
+    void *__restrict__ weight_ptr;
+    void *__restrict__ bias_ptr;
+    void *__restrict__ out_ptr;
+
+    void *__restrict__ conv_state_ptr;
+    int32_t *__restrict__ cache_seqlens;
+
+    // Only used if the elements of the batch are gathered from a larger buffer,
+    // which may happen for continuous batching.
+    int32_t *__restrict__ conv_state_indices_ptr;
+
+    void *__restrict__ seq_idx_ptr;
+
+    // No __restrict__ since initial_states could be the same as final_states.
+    void * initial_states_ptr;
+    index_t initial_states_batch_stride;
+    index_t initial_states_l_stride;
+    index_t initial_states_c_stride;
+
+    void * final_states_ptr;
+    index_t final_states_batch_stride;
+    index_t final_states_l_stride;
+    index_t final_states_c_stride;
+};
+
+struct ConvParamsBwd: public ConvParamsBase {
+    index_t dx_batch_stride;
+    index_t dx_c_stride;
+    index_t dx_l_stride;
+    index_t dweight_c_stride;
+    index_t dweight_width_stride;
+    index_t dout_batch_stride;
+    index_t dout_c_stride;
+    index_t dout_l_stride;
+
+    // Common data pointers.
+    void *__restrict__ dx_ptr;
+    void *__restrict__ dweight_ptr;
+    void *__restrict__ dbias_ptr;
+    void *__restrict__ dout_ptr;
+
+    void * dinitial_states_ptr;
+    index_t dinitial_states_batch_stride;
+    index_t dinitial_states_l_stride;
+    index_t dinitial_states_c_stride;
+
+    void * dfinal_states_ptr;
+    index_t dfinal_states_batch_stride;
+    index_t dfinal_states_l_stride;
+    index_t dfinal_states_c_stride;
+};

causal-conv1d/causal_conv1d_bwd.cu

@@ -0,0 +1,627 @@
+/******************************************************************************
+ * Copyright (c) 2024, Tri Dao.
+ ******************************************************************************/
+
+#include <c10/util/BFloat16.h>
+#include <c10/util/Half.h>
+#include <c10/cuda/CUDAException.h>  // For C10_CUDA_CHECK and C10_CUDA_KERNEL_LAUNCH_CHECK
+
+#ifndef USE_ROCM
+    #include <cub/block/block_load.cuh>
+    #include <cub/block/block_store.cuh>
+    #include <cub/block/block_reduce.cuh>
+#else
+    #include <hipcub/hipcub.hpp>
+    namespace cub = hipcub;
+#endif
+
+#include "causal_conv1d.h"
+#include "causal_conv1d_common.h"
+#include "static_switch.h"
+
+template<int kNThreads_, int kWidth_, bool kSiluAct_, bool kIsVecLoad_, typename input_t_, typename weight_t_>
+struct Causal_conv1d_bwd_kernel_traits {
+    using input_t = input_t_;
+    using weight_t = weight_t_;
+    static constexpr int kNThreads = kNThreads_;
+    static constexpr int kWidth = kWidth_;
+    static constexpr bool kSiluAct = kSiluAct_;
+    static constexpr int kNBytes = sizeof(input_t);
+    static_assert(kNBytes == 2 || kNBytes == 4);
+    static constexpr int kNElts = kNBytes == 4 ? 4 : 8;
+    static_assert(kWidth <= kNElts);
+    // It's possible that we need to do 2 rounds of exchange if input_t is 16 bits
+    // (since then we'd have 8 values of float, and each round we can exchange 4 floats).
+    static constexpr int kNExchangeRounds = sizeof(float) / sizeof(input_t);
+    static constexpr bool kIsVecLoad = kIsVecLoad_;
+    using vec_t = typename BytesToType<kNBytes * kNElts>::Type;
+    using BlockLoadT = cub::BlockLoad<input_t, kNThreads, kNElts, cub::BLOCK_LOAD_WARP_TRANSPOSE>;
+    using BlockLoadVecT = cub::BlockLoad<vec_t, kNThreads, 1, cub::BLOCK_LOAD_DIRECT>;
+    using BlockStoreT = cub::BlockStore<input_t, kNThreads, kNElts, cub::BLOCK_STORE_WARP_TRANSPOSE>;
+    using BlockStoreVecT = cub::BlockStore<vec_t, kNThreads, 1, cub::BLOCK_STORE_DIRECT>;
+    using BlockReduceFloatT = cub::BlockReduce<float, kNThreads>;
+    static constexpr int kSmemIOSize = kIsVecLoad
+        ? 0
+        : custom_max({sizeof(typename BlockLoadT::TempStorage), sizeof(typename BlockStoreT::TempStorage)});
+    static constexpr int kSmemExchangeSize = kNThreads * kNBytes * kNElts * (!kSiluAct ? 1 : kNExchangeRounds + 1);
+    static constexpr int kSmemSize = custom_max({kSmemExchangeSize,
+            int(sizeof(typename BlockReduceFloatT::TempStorage))}) + (kIsVecLoad ? 0 : kSmemIOSize);
+};
+
+template<typename Ktraits>
+__global__ __launch_bounds__(Ktraits::kNThreads)
+void causal_conv1d_bwd_kernel(ConvParamsBwd params) {
+    constexpr int kWidth = Ktraits::kWidth;
+    constexpr int kNThreads = Ktraits::kNThreads;
+    constexpr bool kSiluAct = Ktraits::kSiluAct;
+    static constexpr int kNElts = Ktraits::kNElts;
+    constexpr int kNExchangeRounds = Ktraits::kNExchangeRounds;
+    static constexpr bool kIsVecLoad = Ktraits::kIsVecLoad;
+    using input_t = typename Ktraits::input_t;
+    using vec_t = typename Ktraits::vec_t;
+    using weight_t = typename Ktraits::weight_t;
+
+    // Shared memory.
+    extern __shared__ char smem_[];
+    auto& smem_load = reinterpret_cast<typename Ktraits::BlockLoadT::TempStorage&>(smem_);
+    auto& smem_load_vec = reinterpret_cast<typename Ktraits::BlockLoadVecT::TempStorage&>(smem_);
+    auto& smem_store = reinterpret_cast<typename Ktraits::BlockStoreT::TempStorage&>(smem_);
+    auto& smem_store_vec = reinterpret_cast<typename Ktraits::BlockStoreVecT::TempStorage&>(smem_);
+    vec_t *smem_exchange = reinterpret_cast<vec_t *>(smem_ + Ktraits::kSmemIOSize);
+    vec_t *smem_exchange_x = reinterpret_cast<vec_t *>(smem_ + Ktraits::kSmemIOSize) + kNThreads * kNExchangeRounds;
+    auto& smem_reduce_float = *reinterpret_cast<typename Ktraits::BlockReduceFloatT::TempStorage*>(smem_ + Ktraits::kSmemIOSize);
+
+    const int tidx = threadIdx.x;
+    const int batch_id = blockIdx.x;
+    const int dim_id = blockIdx.y;
+    input_t *x = reinterpret_cast<input_t *>(params.x_ptr) + batch_id * params.x_batch_stride
+        + dim_id * params.x_c_stride;
+    weight_t *weight = reinterpret_cast<weight_t *>(params.weight_ptr) + dim_id * params.weight_c_stride;
+    input_t *dout = reinterpret_cast<input_t *>(params.dout_ptr) + batch_id * params.dout_batch_stride
+        + dim_id * params.dout_c_stride;
+    input_t *dx = reinterpret_cast<input_t *>(params.dx_ptr) + batch_id * params.dx_batch_stride
+        + dim_id * params.dx_c_stride;
+    float *dweight = reinterpret_cast<float *>(params.dweight_ptr) + dim_id * params.dweight_c_stride;
+    float bias_val = params.bias_ptr == nullptr ? 0.f : float(reinterpret_cast<weight_t *>(params.bias_ptr)[dim_id]);
+
+    // Thread kNThreads - 1 will load the first elements of the next chunk so we initialize those to 0.
+    if (tidx == 0) {
+        if constexpr (!kSiluAct) {
+            input_t zeros[kNElts] = {0};
+            smem_exchange[0] = reinterpret_cast<vec_t *>(zeros)[0];
+        } else {
+            float zeros[kNElts] = {0};
+            #pragma unroll
+            for (int r = 0; r < kNExchangeRounds; ++r) {
+                smem_exchange[r * kNThreads] = reinterpret_cast<vec_t *>(zeros)[r];
+            }
+        }
+    }
+
+    float weight_vals[kWidth];
+    #pragma unroll
+    for (int i = 0; i < kWidth; ++i) { weight_vals[i] = weight[i * params.weight_width_stride]; }
+
+    float dweight_vals[kWidth] = {0};
+    float dbias_val = 0;
+
+    constexpr int kChunkSize = kNThreads * kNElts;
+    const int n_chunks = (params.seqlen + kChunkSize - 1) / kChunkSize;
+    x += (n_chunks - 1) * kChunkSize;
+    dout += (n_chunks - 1) * kChunkSize;
+    dx += (n_chunks - 1) * kChunkSize;
+    for (int chunk = n_chunks - 1; chunk >= 0; --chunk) {
+        input_t x_vals_load[2 * kNElts] = {0};
+        input_t dout_vals_load[2 * kNElts] = {0};
+        if constexpr(kIsVecLoad) {
+            typename Ktraits::BlockLoadVecT(smem_load_vec).Load(reinterpret_cast<vec_t*>(x), *reinterpret_cast<vec_t (*)[1]>(&x_vals_load[kNElts]), (params.seqlen - chunk * kChunkSize) / kNElts);
+            typename Ktraits::BlockLoadVecT(smem_load_vec).Load(reinterpret_cast<vec_t*>(dout), *reinterpret_cast<vec_t (*)[1]>(&dout_vals_load[0]), (params.seqlen - chunk * kChunkSize) / kNElts);
+        } else {
+            __syncthreads();
+            typename Ktraits::BlockLoadT(smem_load).Load(x, *reinterpret_cast<input_t (*)[kNElts]>(&x_vals_load[kNElts]), params.seqlen - chunk * kChunkSize);
+            __syncthreads();
+            typename Ktraits::BlockLoadT(smem_load).Load(dout, *reinterpret_cast<input_t (*)[kNElts]>(&dout_vals_load[0]), params.seqlen - chunk * kChunkSize);
+        }
+        float dout_vals[2 * kNElts], x_vals[2 * kNElts];
+        if constexpr (!kSiluAct) {
+            __syncthreads();
+            // Thread 0 don't write yet, so that thread kNThreads - 1 can read
+            // the first elements of the next chunk.
+            if (tidx > 0) { smem_exchange[tidx] = reinterpret_cast<vec_t *>(dout_vals_load)[0]; }
+            __syncthreads();
+            reinterpret_cast<vec_t *>(dout_vals_load)[1] = smem_exchange[tidx < kNThreads - 1 ? tidx + 1 : 0];
+            __syncthreads();
+            // Now thread 0 can write the first elements of the current chunk.
+            if (tidx == 0) { smem_exchange[tidx] = reinterpret_cast<vec_t *>(dout_vals_load)[0]; }
+            #pragma unroll
+            for (int i = 0; i < 2 * kNElts; ++i) {
+                dout_vals[i] = float(dout_vals_load[i]);
+                x_vals[i] = float(x_vals_load[i]);
+            }
+        } else {
+            if (tidx == 0 && chunk > 0) {
+                if constexpr(kIsVecLoad) {
+                    reinterpret_cast<vec_t *>(x_vals_load)[0] = reinterpret_cast<vec_t *>(x)[-1];
+                } else {
+                    #pragma unroll
+                    for (int i = 0; i < kNElts; ++i) {
+                        if (chunk * kChunkSize + i < params.seqlen) { x_vals_load[i] = x[-kNElts + i]; }
+                    }
+                }
+            }
+            __syncthreads();
+            smem_exchange_x[tidx] = reinterpret_cast<vec_t *>(x_vals_load)[1];
+            __syncthreads();
+            if (tidx > 0) { reinterpret_cast<vec_t *>(x_vals_load)[0] = smem_exchange_x[tidx - 1]; }
+            #pragma unroll
+            for (int i = 0; i < 2 * kNElts; ++i) { x_vals[i] = float(x_vals_load[i]); }
+            // Recompute the output
+            #pragma unroll
+            for (int i = 0; i < kNElts; ++i) {
+                float out_val = bias_val;
+                #pragma unroll
+                for (int w = 0; w < kWidth; ++w) {
+                    out_val += weight_vals[w] * x_vals[kNElts + i - (kWidth - w - 1)];
+                }
+                float out_sigmoid_val = 1.0f / (1.0f + expf(-out_val));
+                dout_vals[i] = float(dout_vals_load[i]) * out_sigmoid_val
+                               * (1.0f + out_val * (1.0f - out_sigmoid_val));
+            }
+            // Exchange the dout_vals. It's possible that we need to do 2 rounds of exchange
+            // if input_t is 16 bits (since then we'd have 8 values of float)
+            __syncthreads();
+            // Thread 0 don't write yet, so that thread kNThreads - 1 can read
+            // the first elements of the next chunk.
+            if (tidx > 0) {
+                #pragma unroll
+                for (int r = 0; r < kNExchangeRounds; ++r) {
+                    smem_exchange[r * kNThreads + tidx] = reinterpret_cast<vec_t *>(dout_vals)[r];
+                }
+            }
+            __syncthreads();
+            #pragma unroll
+            for (int r = 0; r < kNExchangeRounds; ++r) {
+                reinterpret_cast<vec_t *>(dout_vals)[kNExchangeRounds + r]
+                    = smem_exchange[r * kNThreads + (tidx < kNThreads - 1 ? tidx + 1 : 0)];
+            }
+            __syncthreads();
+            // Now thread 0 can write the first elements of the current chunk.
+            if (tidx == 0) {
+                #pragma unroll
+                for (int r = 0; r < kNExchangeRounds; ++r) {
+                    smem_exchange[r * kNThreads + tidx] = reinterpret_cast<vec_t *>(dout_vals)[r];
+                }
+            }
+        }
+        dout -= kChunkSize;
+        x -= kChunkSize;
+
+        #pragma unroll
+        for (int i = 0; i < kNElts; ++i) { dbias_val += dout_vals[i]; }
+
+        float dx_vals[kNElts] = {0};
+        #pragma unroll
+        for (int i = 0; i < kNElts; ++i) {
+            #pragma unroll
+            for (int w = 0; w < kWidth; ++w) {
+                dx_vals[i] += weight_vals[w] * dout_vals[i + kWidth - w - 1];
+            }
+        }
+
+        input_t dx_vals_store[kNElts];
+        #pragma unroll
+        for (int i = 0; i < kNElts; ++i) { dx_vals_store[i] = dx_vals[i]; }
+        if constexpr(kIsVecLoad) {
+            typename Ktraits::BlockStoreVecT(smem_store_vec).Store(reinterpret_cast<vec_t*>(dx), reinterpret_cast<vec_t (&)[1]>(dx_vals_store), (params.seqlen - chunk * kChunkSize) / kNElts);
+        } else {
+            typename Ktraits::BlockStoreT(smem_store).Store(dx, dx_vals_store, params.seqlen - chunk * kChunkSize);
+        }
+        dx -= kChunkSize;
+
+        #pragma unroll
+        for (int w = 0; w < kWidth; ++w) {
+            #pragma unroll
+            for (int i = 0; i < kNElts; ++i) {
+                dweight_vals[w] += x_vals[kNElts + i] * dout_vals[i + kWidth - w - 1];
+            }
+        }
+    }
+
+    #pragma unroll
+    for (int w = 0; w < kWidth; ++w) {
+        __syncthreads();
+        dweight_vals[w] = typename Ktraits::BlockReduceFloatT(smem_reduce_float).Sum(dweight_vals[w]);
+        if (tidx == 0) {
+            atomicAdd(&reinterpret_cast<float *>(dweight)[w * params.dweight_width_stride], dweight_vals[w]);
+        }
+    }
+    if (params.bias_ptr != nullptr) {
+        __syncthreads();
+        dbias_val = typename Ktraits::BlockReduceFloatT(smem_reduce_float).Sum(dbias_val);
+        if (tidx == 0) {
+            atomicAdd(&reinterpret_cast<float *>(params.dbias_ptr)[dim_id], dbias_val);
+        }
+    }
+}
+
+template<int kNThreads, int kWidth, typename input_t, typename weight_t>
+void causal_conv1d_bwd_launch(ConvParamsBwd &params, cudaStream_t stream) {
+    static constexpr int kNElts = sizeof(input_t) == 4 ? 4 : 8;
+    BOOL_SWITCH(params.seqlen % kNElts == 0, kIsVecLoad, [&] {
+        BOOL_SWITCH(params.silu_activation, kSiluAct, [&] {
+            using Ktraits = Causal_conv1d_bwd_kernel_traits<kNThreads, kWidth, kSiluAct, kIsVecLoad, input_t, weight_t>;
+            constexpr int kSmemSize = Ktraits::kSmemSize;
+            dim3 grid(params.batch, params.dim);
+            auto kernel = &causal_conv1d_bwd_kernel<Ktraits>;
+
+            if (kSmemSize >= 48 * 1024) {
+                #ifndef USE_ROCM
+                C10_CUDA_CHECK(cudaFuncSetAttribute(
+                    kernel, cudaFuncAttributeMaxDynamicSharedMemorySize, kSmemSize));
+                #else
+                // There is a slight signature discrepancy in HIP and CUDA "FuncSetAttribute" function.
+                C10_CUDA_CHECK(cudaFuncSetAttribute(
+                    (void *) kernel, cudaFuncAttributeMaxDynamicSharedMemorySize, kSmemSize));
+                std::cerr << "Warning (causal_conv1d bwd launch): attempting to set maxDynamicSharedMemorySize on an AMD GPU which is currently a non-op (in ROCm versions <= 6.1). This might lead to undefined behavior. \n" << std::endl;
+                #endif
+            }
+
+
+            kernel<<<grid, Ktraits::kNThreads, kSmemSize, stream>>>(params);
+            C10_CUDA_KERNEL_LAUNCH_CHECK();
+        });
+    });
+}
+
+template<typename input_t, typename weight_t>
+void causal_conv1d_bwd_cuda(ConvParamsBwd &params, cudaStream_t stream) {
+    if (params.width == 2) {
+        causal_conv1d_bwd_launch<128, 2, input_t, weight_t>(params, stream);
+    } else if (params.width == 3) {
+        causal_conv1d_bwd_launch<128, 3, input_t, weight_t>(params, stream);
+    } else if (params.width == 4) {
+        causal_conv1d_bwd_launch<128, 4, input_t, weight_t>(params, stream);
+    }
+}
+
+template<int kNThreads_, int kWidth_, int kChunkSizeL_, bool kSiluAct_, bool kIsVecLoad_, typename input_t_, typename weight_t_>
+struct Causal_conv1d_channellast_bwd_kernel_traits {
+    // The cache line is 128 bytes, and we try to read 16 bytes per thread.
+    // So we have 8 threads per "row", so 32 or 64 elements in the channel dimension.
+    // That leaves 4 columns per warp, and so 16 columns per block (assuming each block has 128
+    // threads). Each each load is 16 x 32|64 elements in the L x C dimensions.
+    using input_t = input_t_;
+    using weight_t = weight_t_;
+    static constexpr bool kSiluAct = kSiluAct_;
+    static constexpr int kNThreads = kNThreads_;
+    static_assert(kNThreads % 32 == 0);
+    static constexpr int kNWarps = kNThreads / 32;
+    static constexpr int kWidth = kWidth_;
+    static constexpr int kChunkSizeL = kChunkSizeL_;
+    static constexpr int kNBytes = sizeof(input_t);
+    static_assert(kNBytes == 2 || kNBytes == 4);
+    static constexpr int kNElts = kNBytes == 4 ? 4 : 8;
+    static constexpr int kNEltsPerRow = 128 / kNBytes;
+    static constexpr int kNThreadsPerRow = kNEltsPerRow / kNElts;  // Always 8 for now
+    static_assert(kNThreadsPerRow * kNBytes * kNElts == 128);
+    static constexpr int kNColsPerWarp = 32 / kNThreadsPerRow;  // Always 4 for now
+    static_assert(kNColsPerWarp * kNThreadsPerRow == 32);
+    static constexpr int kNColsPerLoad = kNColsPerWarp * kNWarps;
+    static constexpr int kNLoads = kChunkSizeL / kNColsPerLoad;
+    static_assert(kNLoads * kNColsPerLoad == kChunkSizeL);
+    static constexpr bool kIsVecLoad = kIsVecLoad_;
+    using vec_t = typename BytesToType<kNBytes * kNElts>::Type;
+    // using BlockLoadT = cub::BlockLoad<input_t, kNThreads, kNItems, cub::BLOCK_LOAD_WARP_TRANSPOSE>;
+    // using BlockStoreT = cub::BlockStore<input_t, kNThreads, kNItems, cub::BLOCK_STORE_WARP_TRANSPOSE>;
+    // static constexpr int kSmemSize = std::max({sizeof(typename BlockLoadT::TempStorage),
+    //                                            sizeof(typename BlockStoreT::TempStorage)});
+    // static constexpr int kSmemSize = kChunkSizeL * kNEltsPerRow * kNBytes;
+};
+
+template<typename Ktraits, bool kHasSeqIdx, bool kHasDfinalStates>
+__global__ __launch_bounds__(Ktraits::kNThreads)
+void causal_conv1d_channellast_bwd_kernel(ConvParamsBwd params) {
+    constexpr int kWidth = Ktraits::kWidth;
+    constexpr int kNThreads = Ktraits::kNThreads;
+    constexpr bool kSiluAct = Ktraits::kSiluAct;
+    constexpr int kNElts = Ktraits::kNElts;
+    constexpr int kNWarp = Ktraits::kNWarps;
+    constexpr int kNThreadsPerC = Ktraits::kNThreadsPerRow;
+    constexpr int kLPerLoad = Ktraits::kNColsPerLoad;
+    constexpr int kChunkSizeL = Ktraits::kChunkSizeL;
+    constexpr int kChunkSizeC = Ktraits::kNEltsPerRow;
+    using input_t = typename Ktraits::input_t;
+    using vec_t = typename Ktraits::vec_t;
+    using weight_t = typename Ktraits::weight_t;
+
+    // Shared memory.
+    __shared__ input_t dout_smem[kChunkSizeL + kWidth - 1][kChunkSizeC + kNElts];
+    __shared__ input_t x_smem[kWidth - 1 + kChunkSizeL + kWidth - 1][kChunkSizeC + kNElts];
+
+    const int batch_id = blockIdx.x;
+    const int chunk_l_id = blockIdx.y;
+    const int chunk_c_id = blockIdx.z;
+    const int tid = threadIdx.x;
+    const int l_idx = tid / kNThreadsPerC;
+    const int c_idx = tid % kNThreadsPerC;
+    input_t *x = reinterpret_cast<input_t *>(params.x_ptr) + batch_id * params.x_batch_stride
+        + (chunk_l_id * kChunkSizeL + l_idx) * params.x_l_stride + chunk_c_id * kChunkSizeC + c_idx * kNElts;
+    weight_t *weight = reinterpret_cast<weight_t *>(params.weight_ptr)
+        + chunk_c_id * kChunkSizeC * params.weight_c_stride;
+    input_t *dout = reinterpret_cast<input_t *>(params.dout_ptr) + batch_id * params.dout_batch_stride
+        + (chunk_l_id * kChunkSizeL + l_idx) * params.dout_l_stride + chunk_c_id * kChunkSizeC + c_idx * kNElts;
+    input_t *dx = reinterpret_cast<input_t *>(params.dx_ptr) + batch_id * params.dx_batch_stride
+        + (chunk_l_id * kChunkSizeL + l_idx) * params.dx_l_stride + chunk_c_id * kChunkSizeC + c_idx * kNElts;
+    float *dweight = reinterpret_cast<float *>(params.dweight_ptr)
+        + chunk_c_id * kChunkSizeC * params.dweight_c_stride;
+    int *seq_idx = !kHasSeqIdx ? nullptr : reinterpret_cast<int *>(params.seq_idx_ptr)
+        + batch_id * params.seqlen + chunk_l_id * kChunkSizeL;
+    input_t *initial_states = params.initial_states_ptr == nullptr || chunk_l_id > 0 ? nullptr
+        : reinterpret_cast<input_t *>(params.initial_states_ptr) + batch_id * params.initial_states_batch_stride + l_idx * params.initial_states_l_stride + chunk_c_id * kChunkSizeC + c_idx * kNElts;
+    input_t *dinitial_states = params.dinitial_states_ptr == nullptr || chunk_l_id > 0 ? nullptr
+        : reinterpret_cast<input_t *>(params.dinitial_states_ptr) + batch_id * params.dinitial_states_batch_stride + l_idx * params.dinitial_states_l_stride + chunk_c_id * kChunkSizeC + c_idx * kNElts;
+    input_t *dfinal_states = params.dfinal_states_ptr == nullptr ? nullptr
+        : reinterpret_cast<input_t *>(params.dfinal_states_ptr) + batch_id * params.dfinal_states_batch_stride + chunk_c_id * kChunkSizeC;
+
+    #pragma unroll
+    for (int l = 0; l < Ktraits::kNLoads; ++l) {
+        input_t dout_vals_load[kNElts] = {0};
+        input_t x_vals_load[kNElts] = {0};
+        if (chunk_l_id * kChunkSizeL + l * kLPerLoad + l_idx < params.seqlen
+            && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+            reinterpret_cast<vec_t *>(dout_vals_load)[0] = *reinterpret_cast<vec_t *>(dout + l * kLPerLoad * params.dout_l_stride);
+            reinterpret_cast<vec_t *>(x_vals_load)[0] = *reinterpret_cast<vec_t *>(x + l * kLPerLoad * params.x_l_stride);
+        }
+        reinterpret_cast<vec_t *>(dout_smem[l * kLPerLoad + l_idx])[c_idx] = reinterpret_cast<vec_t *>(dout_vals_load)[0];
+        reinterpret_cast<vec_t *>(x_smem[kWidth - 1 + l * kLPerLoad + l_idx])[c_idx] = reinterpret_cast<vec_t *>(x_vals_load)[0];
+    }
+    // Load the elements from the previous chunk or next chunk that are needed for convolution.
+    if (l_idx < kWidth - 1) {
+        input_t dout_vals_load[kNElts] = {0};
+        input_t x_vals_load[kNElts] = {0};
+        if ((chunk_l_id + 1) * kChunkSizeL + l_idx < params.seqlen
+            && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+            reinterpret_cast<vec_t *>(dout_vals_load)[0] = *reinterpret_cast<vec_t *>(dout + kChunkSizeL * params.dout_l_stride);
+        }
+        if (chunk_l_id * kChunkSizeL + l_idx - (kWidth - 1) >= 0
+            && chunk_l_id * kChunkSizeL + l_idx - (kWidth - 1) < params.seqlen
+            && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+            reinterpret_cast<vec_t *>(x_vals_load)[0] = *reinterpret_cast<vec_t *>(x - (kWidth - 1) * params.x_l_stride);
+        } else if (initial_states != nullptr
+                   && chunk_l_id * kChunkSizeL + l_idx - (kWidth - 1) < 0
+                   && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+            reinterpret_cast<vec_t *>(x_vals_load)[0] = *reinterpret_cast<vec_t *>(initial_states);
+        }
+        reinterpret_cast<vec_t *>(dout_smem[kChunkSizeL + l_idx])[c_idx] = reinterpret_cast<vec_t *>(dout_vals_load)[0];
+        reinterpret_cast<vec_t *>(x_smem[l_idx])[c_idx] = reinterpret_cast<vec_t *>(x_vals_load)[0];
+    }
+    // Need to load (kWdith - 1) extra x's on the right to recompute the (kChunkSizeL + kWidth - 1) outputs
+    if constexpr (kSiluAct) {
+        if (l_idx < kWidth - 1) {
+            input_t x_vals_load[kNElts] = {0};
+            if ((chunk_l_id + 1) * kChunkSizeL + l_idx < params.seqlen
+                && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+                reinterpret_cast<vec_t *>(x_vals_load)[0] = *reinterpret_cast<vec_t *>(x + kChunkSizeL * params.x_l_stride);
+            }
+            reinterpret_cast<vec_t *>(x_smem[kWidth - 1 + kChunkSizeL + l_idx])[c_idx] = reinterpret_cast<vec_t *>(x_vals_load)[0];
+        }
+    }
+
+    __syncthreads();
+
+    constexpr int kLPerThread = constexpr_min(kChunkSizeL * kChunkSizeC / kNThreads, kChunkSizeL);
+    static_assert(kLPerThread * kNThreads == kChunkSizeL * kChunkSizeC);
+    constexpr int kNThreadsPerRow = kChunkSizeL / kLPerThread;
+    static_assert(kNThreadsPerRow * kLPerThread == kChunkSizeL);
+    // kChunkSizeL, kLPerThread, kNThreadsPerRow should be powers of 2 for simplicity
+    static_assert((kChunkSizeL & (kChunkSizeL - 1)) == 0);
+    static_assert((kLPerThread & (kLPerThread - 1)) == 0);
+    static_assert((kNThreadsPerRow & (kNThreadsPerRow - 1)) == 0);
+    static_assert(kNThreadsPerRow <= 32);
+
+    const int row_idx = tid / kNThreadsPerRow;
+    const int col_idx = tid % kNThreadsPerRow;
+
+    float bias_val = params.bias_ptr == nullptr || chunk_c_id * kChunkSizeC + row_idx >= params.dim ? 0.f : float(reinterpret_cast<weight_t *>(params.bias_ptr)[chunk_c_id * kChunkSizeC + row_idx]);
+    float weight_vals[kWidth] = {0};
+    if (chunk_c_id * kChunkSizeC + row_idx < params.dim) {
+        #pragma unroll
+        for (int w = 0; w < kWidth; ++w) {
+            weight_vals[w] = weight[row_idx * params.weight_c_stride + w * params.weight_width_stride];
+        }
+    }
+    float dout_vals[kLPerThread + kWidth - 1];
+    float x_vals[kWidth - 1 + kLPerThread + kWidth - 1];
+    #pragma unroll
+    for (int i = 0; i < kWidth - 1 + kLPerThread; ++i) {
+        dout_vals[i] = float(dout_smem[col_idx * kLPerThread + i][row_idx]);
+        x_vals[i] = float(x_smem[col_idx * kLPerThread + i][row_idx]);
+    }
+
+    int seq_idx_thread[kWidth - 1 + kLPerThread + kWidth - 1];
+    if constexpr (kHasSeqIdx) {
+        #pragma unroll
+        for (int i = 0; i < kWidth - 1 + kLPerThread + kWidth - 1; ++i) {
+            const int l_idx = chunk_l_id * kChunkSizeL + col_idx * kLPerThread + i - (kWidth - 1);
+            seq_idx_thread[i] = l_idx >= 0 && l_idx < params.seqlen ? seq_idx[col_idx * kLPerThread + i - (kWidth - 1)] : -1;
+        }
+    }
+
+    if constexpr (kSiluAct) {  // Recompute the output
+        #pragma unroll
+        for (int i = kWidth - 1 + kLPerThread; i < kWidth - 1 + kLPerThread + kWidth - 1; ++i) {
+            x_vals[i] = float(x_smem[col_idx * kLPerThread + i][row_idx]);
+        }
+        #pragma unroll
+        for (int i = 0; i < kLPerThread + kWidth - 1; ++i) {
+            float out_val = bias_val;
+            const int seq_idx_cur = !kHasSeqIdx ? 0 : seq_idx_thread[i + kWidth - 1];
+            #pragma unroll
+            for (int w = 0; w < kWidth; ++w) {
+                if constexpr (!kHasSeqIdx) {
+                    out_val += weight_vals[w] * x_vals[i + w];
+                } else {
+                    out_val += seq_idx_thread[i + w] == seq_idx_cur ? weight_vals[w] * x_vals[i + w] : 0.f;
+                }
+            }
+            float out_val_sigmoid = 1.f / (1.f + expf(-out_val));
+            dout_vals[i] *= out_val_sigmoid * (1 + out_val * (1 - out_val_sigmoid));
+        }
+    }
+
+    float dweight_vals[kWidth] = {0};
+    SumOp<float> sum_op;
+    #pragma unroll
+    for (int w = 0; w < kWidth; ++w) {
+        #pragma unroll
+        for (int i = 0; i < kLPerThread; ++i) {
+            if constexpr (!kHasSeqIdx) {
+                dweight_vals[w] += x_vals[i + w] * dout_vals[i];
+            } else {
+                dweight_vals[w] += seq_idx_thread[i + w] == seq_idx_thread[kWidth - 1 + i] ? x_vals[i + w] * dout_vals[i] : 0.f;
+            }
+        }
+        dweight_vals[w] = Allreduce<kNThreadsPerRow>::run(dweight_vals[w], sum_op);
+        if (col_idx == 0 && chunk_c_id * kChunkSizeC + row_idx < params.dim) {
+            atomicAdd(&reinterpret_cast<float *>(dweight)[row_idx * params.dweight_c_stride + w * params.dweight_width_stride], dweight_vals[w]);
+        }
+    }
+
+    if (params.bias_ptr != nullptr) {
+        float dbias_val = 0.f;
+        for (int i = 0; i < kLPerThread; ++i) { dbias_val += dout_vals[i]; }
+        dbias_val = Allreduce<kNThreadsPerRow>::run(dbias_val, sum_op);
+        if (col_idx == 0 && chunk_c_id * kChunkSizeC + row_idx < params.dim) {
+            atomicAdd(&reinterpret_cast<float *>(params.dbias_ptr)[chunk_c_id * kChunkSizeC + row_idx], dbias_val);
+        }
+    }
+
+    float dx_vals[kLPerThread] = {0};
+    #pragma unroll
+    for (int i = 0; i < kLPerThread; ++i) {
+        const int seq_idx_cur = !kHasSeqIdx ? 0 : seq_idx_thread[i + kWidth - 1];
+        #pragma unroll
+        for (int w = 0; w < kWidth; ++w) {
+            if constexpr (!kHasSeqIdx) {
+                dx_vals[i] += weight_vals[kWidth - 1 - w] * dout_vals[i + w];
+            } else {
+                dx_vals[i] += seq_idx_thread[kWidth - 1 + i + w] == seq_idx_cur ? weight_vals[kWidth - 1 - w] * dout_vals[i + w] : 0.f;
+            }
+        }
+        // if (dfinal_states != nullptr) {
+        if constexpr (kHasDfinalStates) {
+            if (chunk_l_id * kChunkSizeL + col_idx * kLPerThread + i >= params.seqlen - kWidth + 1
+                && chunk_l_id * kChunkSizeL + col_idx * kLPerThread + i < params.seqlen
+                && chunk_c_id * kChunkSizeC + row_idx < params.dim) {
+                dx_vals[i] += float(dfinal_states[((chunk_l_id * kChunkSizeL + col_idx * kLPerThread + i) - (params.seqlen - kWidth + 1)) * params.dfinal_states_l_stride + row_idx * params.dfinal_states_c_stride]);
+            }
+        }
+    }
+
+    float dxinit_vals[kWidth - 1] = {0};
+    static_assert(kLPerThread >= kWidth - 1);  // So only threads with col_idx == 0 need to handle dinitial_states
+    if (dinitial_states != nullptr && col_idx == 0) {
+        #pragma unroll
+        for (int i = 0; i < kWidth - 1; ++i) {
+            #pragma unroll
+            for (int w = 0; w < kWidth; ++w) {
+                dxinit_vals[i] += i + w - (kWidth - 1) >= 0 ? weight_vals[kWidth - 1 - w] * dout_vals[i + w - (kWidth - 1)] : 0.f;
+            }
+            // chunk_l_id must be 0 because dinitial_states != nullptr
+            // if (dfinal_states != nullptr) {
+            if constexpr (kHasDfinalStates) {
+                if (i >= params.seqlen) {
+                    dxinit_vals[i] += float(dfinal_states[(i - params.seqlen) * params.dfinal_states_l_stride + row_idx * params.dfinal_states_c_stride]);
+                }
+            }
+        }
+    }
+
+    __syncthreads();
+    #pragma unroll
+    for (int i = 0; i < kLPerThread; ++i) { x_smem[kWidth - 1 + col_idx * kLPerThread + i][row_idx] = dx_vals[i]; }
+    if (dinitial_states != nullptr && col_idx == 0) {
+        #pragma unroll
+        for (int i = 0; i < kWidth - 1; ++i) { x_smem[i][row_idx] = dxinit_vals[i]; }
+    }
+    __syncthreads();
+
+    #pragma unroll
+    for (int l = 0; l < Ktraits::kNLoads; ++l) {
+        input_t dx_vals_store[kNElts];
+        reinterpret_cast<vec_t *>(dx_vals_store)[0] = reinterpret_cast<vec_t *>(x_smem[kWidth - 1 + l * kLPerLoad + l_idx])[c_idx];
+        if (chunk_l_id * kChunkSizeL + l * kLPerLoad + l_idx < params.seqlen
+            && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+            *reinterpret_cast<vec_t *>(dx + l * kLPerLoad * params.dx_l_stride) = reinterpret_cast<vec_t *>(dx_vals_store)[0];
+        }
+    }
+    if (dinitial_states != nullptr
+        && l_idx < kWidth - 1
+        && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+        input_t dxinit_vals_store[kNElts];
+        reinterpret_cast<vec_t *>(dxinit_vals_store)[0] = reinterpret_cast<vec_t *>(x_smem[l_idx])[c_idx];
+        *reinterpret_cast<vec_t *>(dinitial_states) = reinterpret_cast<vec_t *>(dxinit_vals_store)[0];
+    }
+
+}
+
+template<int kNThreads, int kWidth, typename input_t, typename weight_t>
+void causal_conv1d_channellast_bwd_launch(ConvParamsBwd &params, cudaStream_t stream) {
+    BOOL_SWITCH(params.silu_activation, kSiluAct, [&] {
+        BOOL_SWITCH(params.seq_idx_ptr != nullptr, kHasSeqIdx, [&] {
+            BOOL_SWITCH(params.dfinal_states_ptr != nullptr, kHasDfinalStates, [&] {
+                BOOL_SWITCH(params.seqlen <= 128, kChunkSizeL64, [&] {
+                    // kChunkSizeL = 128 is slightly faster than 64 when seqlen is larger
+                    static constexpr int kChunk = kChunkSizeL64 ? 64 : 128;
+                    using Ktraits = Causal_conv1d_channellast_bwd_kernel_traits<kNThreads, kWidth, kChunk, kSiluAct, true, input_t, weight_t>;
+                    // constexpr int kSmemSize = Ktraits::kSmemSize;
+                    constexpr int kChunkSizeL = Ktraits::kChunkSizeL;
+                    constexpr int kChunkSizeC = Ktraits::kNEltsPerRow;
+                    const int n_chunks_L = (params.seqlen + kChunkSizeL - 1) / kChunkSizeL;
+                    const int n_chunks_C = (params.dim + kChunkSizeC - 1) / kChunkSizeC;
+                    dim3 grid(params.batch, n_chunks_L, n_chunks_C);
+                    dim3 block(Ktraits::kNThreads);
+                    auto kernel = &causal_conv1d_channellast_bwd_kernel<Ktraits, kHasSeqIdx, kHasDfinalStates>;
+                    // if (kSmemSize >= 48 * 1024) {
+                    //     C10_CUDA_CHECK(cudaFuncSetAttribute(
+                    //         kernel, cudaFuncAttributeMaxDynamicSharedMemorySize, kSmemSize));
+                    //     }
+                    // kernel<<<grid, Ktraits::kNThreads, kSmemSize, stream>>>(params);
+                    kernel<<<grid, Ktraits::kNThreads, 0, stream>>>(params);
+                    C10_CUDA_KERNEL_LAUNCH_CHECK();
+                });
+            });
+        });
+    });
+}
+
+template<typename input_t, typename weight_t>
+void causal_conv1d_channellast_bwd_cuda(ConvParamsBwd &params, cudaStream_t stream) {
+    if (params.width == 2) {
+        causal_conv1d_channellast_bwd_launch<128, 2, input_t, weight_t>(params, stream);
+    } else if (params.width == 3) {
+        causal_conv1d_channellast_bwd_launch<128, 3, input_t, weight_t>(params, stream);
+    } else if (params.width == 4) {
+        causal_conv1d_channellast_bwd_launch<128, 4, input_t, weight_t>(params, stream);
+    }
+}
+
+template void causal_conv1d_bwd_cuda<float, float>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_bwd_cuda<at::Half, float>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_bwd_cuda<at::BFloat16, float>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_bwd_cuda<float, at::Half>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_bwd_cuda<at::Half, at::Half>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_bwd_cuda<at::BFloat16, at::Half>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_bwd_cuda<float, at::BFloat16>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_bwd_cuda<at::Half, at::BFloat16>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_bwd_cuda<at::BFloat16, at::BFloat16>(ConvParamsBwd &params, cudaStream_t stream);
+
+template void causal_conv1d_channellast_bwd_cuda<float, float>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_channellast_bwd_cuda<at::Half, float>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_channellast_bwd_cuda<at::BFloat16, float>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_channellast_bwd_cuda<float, at::Half>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_channellast_bwd_cuda<at::Half, at::Half>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_channellast_bwd_cuda<at::BFloat16, at::Half>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_channellast_bwd_cuda<float, at::BFloat16>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_channellast_bwd_cuda<at::Half, at::BFloat16>(ConvParamsBwd &params, cudaStream_t stream);
+template void causal_conv1d_channellast_bwd_cuda<at::BFloat16, at::BFloat16>(ConvParamsBwd &params, cudaStream_t stream);

causal-conv1d/causal_conv1d_common.h

@@ -0,0 +1,98 @@
+/******************************************************************************
+ * Copyright (c) 2023, Tri Dao.
+ ******************************************************************************/
+
+#pragma once
+
+#ifndef USE_ROCM
+    #include <cuda_bf16.h>
+
+    template<typename T>
+    __device__ inline T shuffle_xor(T val, int offset) {
+        return __shfl_xor_sync(uint32_t(-1), val, offset);
+    }
+
+    constexpr size_t custom_max(std::initializer_list<size_t> ilist) 
+    {
+        return std::max(ilist);
+    }
+
+    template<typename T>
+    constexpr T constexpr_min(T a, T b) {
+        return std::min(a, b);
+    }
+
+#else
+    #include <hip/hip_bf16.h>
+
+    template<typename T>
+    __device__ inline T shuffle_xor(T val, int offset) {
+        return __shfl_xor(val, offset);
+    }
+    constexpr size_t custom_max(std::initializer_list<size_t> ilist) 
+    {
+        return *std::max_element(ilist.begin(), ilist.end());
+    }
+
+    template<typename T>
+    constexpr T constexpr_min(T a, T b) {
+        return a < b ? a : b;
+    }
+#endif
+#include <cuda_fp16.h>
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+template<int BYTES> struct BytesToType {};
+
+template<> struct BytesToType<16> {
+    using Type = uint4;
+    static_assert(sizeof(Type) == 16);
+};
+
+template<> struct BytesToType<8> {
+    using Type = uint64_t;
+    static_assert(sizeof(Type) == 8);
+};
+
+template<> struct BytesToType<4> {
+    using Type = uint32_t;
+    static_assert(sizeof(Type) == 4);
+};
+
+template<> struct BytesToType<2> {
+    using Type = uint16_t;
+    static_assert(sizeof(Type) == 2);
+};
+
+template<> struct BytesToType<1> {
+    using Type = uint8_t;
+    static_assert(sizeof(Type) == 1);
+};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+template<typename T>
+struct SumOp {
+__device__ inline T operator()(T const & x, T const & y) { return x + y; }
+};
+
+template<int THREADS>
+struct Allreduce {
+    static_assert(THREADS == 32 || THREADS == 16 || THREADS == 8 || THREADS == 4);
+    template<typename T, typename Operator>
+    static __device__ inline T run(T x, Operator &op) {
+        constexpr int OFFSET = THREADS / 2;
+        x = op(x, shuffle_xor(x, OFFSET));
+        return Allreduce<OFFSET>::run(x, op);
+    }
+};
+
+template<>
+struct Allreduce<2> {
+template<typename T, typename Operator>
+static __device__ inline T run(T x, Operator &op) {
+    x = op(x, shuffle_xor(x, 1));
+    return x;
+}
+};

causal-conv1d/causal_conv1d_fwd.cu

@@ -0,0 +1,399 @@
+/******************************************************************************
+ * Copyright (c) 2024, Tri Dao.
+ ******************************************************************************/
+
+#include <c10/util/BFloat16.h>
+#include <c10/util/Half.h>
+#include <c10/cuda/CUDAException.h>  // For C10_CUDA_CHECK and C10_CUDA_KERNEL_LAUNCH_CHECK
+
+#ifndef USE_ROCM
+    #include <cub/block/block_load.cuh>
+    #include <cub/block/block_store.cuh>
+#else
+    #include <hipcub/hipcub.hpp>
+    namespace cub = hipcub;
+#endif
+
+#include "causal_conv1d.h"
+#include "causal_conv1d_common.h"
+#include "static_switch.h"
+
+template<int kNThreads_, int kWidth_, bool kIsVecLoad_, typename input_t_, typename weight_t_>
+struct Causal_conv1d_fwd_kernel_traits {
+    using input_t = input_t_;
+    using weight_t = weight_t_;
+    static constexpr int kNThreads = kNThreads_;
+    static constexpr int kWidth = kWidth_;
+    static constexpr int kNBytes = sizeof(input_t);
+    static_assert(kNBytes == 2 || kNBytes == 4);
+    static constexpr int kNElts = kNBytes == 4 ? 4 : 8;
+    static_assert(kWidth <= kNElts);
+    static constexpr bool kIsVecLoad = kIsVecLoad_;
+    using vec_t = typename BytesToType<kNBytes * kNElts>::Type;
+    using BlockLoadT = cub::BlockLoad<input_t, kNThreads, kNElts, cub::BLOCK_LOAD_WARP_TRANSPOSE>;
+    using BlockLoadVecT = cub::BlockLoad<vec_t, kNThreads, 1, cub::BLOCK_LOAD_DIRECT>;
+    using BlockStoreT = cub::BlockStore<input_t, kNThreads, kNElts, cub::BLOCK_STORE_WARP_TRANSPOSE>;
+    using BlockStoreVecT = cub::BlockStore<vec_t, kNThreads, 1, cub::BLOCK_STORE_DIRECT>;
+    static constexpr int kSmemIOSize = kIsVecLoad
+        ? 0
+        : custom_max({sizeof(typename BlockLoadT::TempStorage), sizeof(typename BlockStoreT::TempStorage)});
+    static constexpr int kSmemExchangeSize = kNThreads * kNBytes * kNElts;
+    static constexpr int kSmemSize = kSmemIOSize + kSmemExchangeSize;
+};
+
+template<typename Ktraits>
+__global__ __launch_bounds__(Ktraits::kNThreads)
+void causal_conv1d_fwd_kernel(ConvParamsBase params) {
+    constexpr int kWidth = Ktraits::kWidth;
+    constexpr int kNThreads = Ktraits::kNThreads;
+    constexpr int kNElts = Ktraits::kNElts;
+    static constexpr bool kIsVecLoad = Ktraits::kIsVecLoad;
+    using input_t = typename Ktraits::input_t;
+    using vec_t = typename Ktraits::vec_t;
+    using weight_t = typename Ktraits::weight_t;
+
+    // Shared memory.
+    extern __shared__ char smem_[];
+    auto& smem_load = reinterpret_cast<typename Ktraits::BlockLoadT::TempStorage&>(smem_);
+    auto& smem_load_vec = reinterpret_cast<typename Ktraits::BlockLoadVecT::TempStorage&>(smem_);
+    auto& smem_store = reinterpret_cast<typename Ktraits::BlockStoreT::TempStorage&>(smem_);
+    auto& smem_store_vec = reinterpret_cast<typename Ktraits::BlockStoreVecT::TempStorage&>(smem_);
+    vec_t *smem_exchange = reinterpret_cast<vec_t *>(smem_ + Ktraits::kSmemIOSize);
+
+    const int tidx = threadIdx.x;
+    const int batch_id = blockIdx.x;
+    const int channel_id = blockIdx.y;
+    input_t *x = reinterpret_cast<input_t *>(params.x_ptr) + batch_id * params.x_batch_stride
+        + channel_id * params.x_c_stride;
+    weight_t *weight = reinterpret_cast<weight_t *>(params.weight_ptr) + channel_id * params.weight_c_stride;
+    input_t *out = reinterpret_cast<input_t *>(params.out_ptr) + batch_id * params.out_batch_stride
+        + channel_id * params.out_c_stride;
+    float bias_val = params.bias_ptr == nullptr ? 0.f : float(reinterpret_cast<weight_t *>(params.bias_ptr)[channel_id]);
+
+    // Thread 0 will load the last elements of the previous chunk, so we initialize those to 0.
+    if (tidx == 0) {
+        input_t zeros[kNElts] = {0};
+        smem_exchange[kNThreads - 1] = reinterpret_cast<vec_t *>(zeros)[0];
+    }
+
+    float weight_vals[kWidth];
+    #pragma unroll
+    for (int i = 0; i < kWidth; ++i) { weight_vals[i] = float(weight[i * params.weight_width_stride]); }
+
+    constexpr int kChunkSize = kNThreads * kNElts;
+    const int n_chunks = (params.seqlen + kChunkSize - 1) / kChunkSize;
+    for (int chunk = 0; chunk < n_chunks; ++chunk) {
+        input_t x_vals_load[2 * kNElts] = {0};
+        if constexpr(kIsVecLoad) {
+            typename Ktraits::BlockLoadVecT(smem_load_vec).Load(reinterpret_cast<vec_t*>(x), *reinterpret_cast<vec_t (*)[1]>(&x_vals_load[kNElts]), (params.seqlen - chunk * kChunkSize) / kNElts);
+        } else {
+            __syncthreads();
+            typename Ktraits::BlockLoadT(smem_load).Load(x, *reinterpret_cast<input_t (*)[kNElts]>(&x_vals_load[kNElts]), params.seqlen - chunk * kChunkSize);
+        }
+        x += kChunkSize;
+        __syncthreads();
+        // Thread kNThreads - 1 don't write yet, so that thread 0 can read
+        // the last elements of the previous chunk.
+        if (tidx < kNThreads - 1) { smem_exchange[tidx] = reinterpret_cast<vec_t *>(x_vals_load)[1]; }
+        __syncthreads();
+        reinterpret_cast<vec_t *>(x_vals_load)[0] = smem_exchange[tidx > 0 ? tidx - 1 : kNThreads - 1];
+        __syncthreads();
+        // Now thread kNThreads - 1 can write the last elements of the current chunk.
+        if (tidx == kNThreads - 1) { smem_exchange[tidx] = reinterpret_cast<vec_t *>(x_vals_load)[1]; }
+
+        float x_vals[2 * kNElts];
+        #pragma unroll
+        for (int i = 0; i < 2 * kNElts; ++i) { x_vals[i] = float(x_vals_load[i]); }
+
+        float out_vals[kNElts];
+        #pragma unroll
+        for (int i = 0; i < kNElts; ++i) {
+            out_vals[i] = bias_val;
+            #pragma unroll
+            for (int w = 0; w < kWidth; ++w) {
+                out_vals[i] += weight_vals[w] * x_vals[kNElts + i - (kWidth - w - 1)];
+            }
+        }
+
+        if (params.silu_activation) {
+            #pragma unroll
+            for (int i = 0; i < kNElts; ++i) {
+                out_vals[i] = out_vals[i] / (1 + expf(-out_vals[i]));
+            }
+        }
+
+        input_t out_vals_store[kNElts];
+        #pragma unroll
+        for (int i = 0; i < kNElts; ++i) { out_vals_store[i] = out_vals[i]; }
+        if constexpr(kIsVecLoad) {
+            typename Ktraits::BlockStoreVecT(smem_store_vec).Store(reinterpret_cast<vec_t*>(out), reinterpret_cast<vec_t (&)[1]>(out_vals_store), (params.seqlen - chunk * kChunkSize) / kNElts);
+        } else {
+            typename Ktraits::BlockStoreT(smem_store).Store(out, out_vals_store, params.seqlen - chunk * kChunkSize);
+        }
+        out += kChunkSize;
+    }
+}
+
+template<int kNThreads, int kWidth, typename input_t, typename weight_t>
+void causal_conv1d_fwd_launch(ConvParamsBase &params, cudaStream_t stream) {
+    static constexpr int kNElts = sizeof(input_t) == 4 ? 4 : 8;
+    BOOL_SWITCH(params.seqlen % kNElts == 0, kIsVecLoad, [&] {
+        using Ktraits = Causal_conv1d_fwd_kernel_traits<kNThreads, kWidth, kIsVecLoad, input_t, weight_t>;
+        constexpr int kSmemSize = Ktraits::kSmemSize;
+        dim3 grid(params.batch, params.dim);
+
+        auto kernel = &causal_conv1d_fwd_kernel<Ktraits>;
+
+        if (kSmemSize >= 48 * 1024) {
+            #ifndef USE_ROCM
+            C10_CUDA_CHECK(cudaFuncSetAttribute(
+                kernel, cudaFuncAttributeMaxDynamicSharedMemorySize, kSmemSize));
+            #else
+            // There is a slight signature discrepancy in HIP and CUDA "FuncSetAttribute" function.
+            C10_CUDA_CHECK(cudaFuncSetAttribute(
+                (void *) kernel, cudaFuncAttributeMaxDynamicSharedMemorySize, kSmemSize));
+            std::cerr << "Warning (causal_conv1d fwd launch): attempting to set maxDynamicSharedMemorySize on an AMD GPU which is currently a non-op (in ROCm versions <= 6.1). This might lead to undefined behavior. \n" << std::endl;
+            #endif
+        }
+        kernel<<<grid, Ktraits::kNThreads, kSmemSize, stream>>>(params);
+
+        C10_CUDA_KERNEL_LAUNCH_CHECK();
+    });
+}
+
+template<typename input_t, typename weight_t>
+void causal_conv1d_fwd_cuda(ConvParamsBase &params, cudaStream_t stream) {
+    if (params.width == 2) {
+        causal_conv1d_fwd_launch<128, 2, input_t, weight_t>(params, stream);
+    } else if (params.width == 3) {
+        causal_conv1d_fwd_launch<128, 3, input_t, weight_t>(params, stream);
+    } else if (params.width == 4) {
+        causal_conv1d_fwd_launch<128, 4, input_t, weight_t>(params, stream);
+    }
+}
+
+template<int kNThreads_, int kWidth_, int kChunkSizeL_, bool kIsVecLoad_, typename input_t_, typename weight_t_>
+struct Causal_conv1d_channellast_fwd_kernel_traits {
+    // The cache line is 128 bytes, and we try to read 16 bytes per thread.
+    // So we have 8 threads per "row", so 32 or 64 elements in the channel dimension.
+    // That leaves 4 columns per warp, and so 16 columns per block (assuming each block has 128
+    // threads). Each each load is 16 x 32|64 elements in the L x C dimensions.
+    using input_t = input_t_;
+    using weight_t = weight_t_;
+    static constexpr int kNThreads = kNThreads_;
+    static_assert(kNThreads % 32 == 0);
+    static constexpr int kNWarps = kNThreads / 32;
+    static constexpr int kWidth = kWidth_;
+    static constexpr int kChunkSizeL = kChunkSizeL_;
+    static constexpr int kNBytes = sizeof(input_t);
+    static_assert(kNBytes == 2 || kNBytes == 4);
+    static constexpr int kNElts = kNBytes == 4 ? 4 : 8;
+    static constexpr int kNEltsPerRow = 128 / kNBytes;
+    static constexpr int kNThreadsPerRow = kNEltsPerRow / kNElts;  // Always 8 for now
+    static_assert(kNThreadsPerRow * kNBytes * kNElts == 128);
+    static constexpr int kNColsPerWarp = 32 / kNThreadsPerRow;  // Always 4 for now
+    static_assert(kNColsPerWarp * kNThreadsPerRow == 32);
+    static constexpr int kNColsPerLoad = kNColsPerWarp * kNWarps;
+    static constexpr int kNLoads = kChunkSizeL / kNColsPerLoad;
+    static_assert(kNLoads * kNColsPerLoad == kChunkSizeL);
+    static constexpr bool kIsVecLoad = kIsVecLoad_;
+    using vec_t = typename BytesToType<kNBytes * kNElts>::Type;
+    // using BlockLoadT = cub::BlockLoad<input_t, kNThreads, kNItems, cub::BLOCK_LOAD_WARP_TRANSPOSE>;
+    // using BlockStoreT = cub::BlockStore<input_t, kNThreads, kNItems, cub::BLOCK_STORE_WARP_TRANSPOSE>;
+    // static constexpr int kSmemSize = std::max({sizeof(typename BlockLoadT::TempStorage),
+    //                                            sizeof(typename BlockStoreT::TempStorage)});
+    // static constexpr int kSmemSize = kChunkSizeL * kNEltsPerRow * kNBytes;
+};
+
+template<typename Ktraits, bool kHasSeqIdx>
+__global__ __launch_bounds__(Ktraits::kNThreads)
+void causal_conv1d_channellast_fwd_kernel(ConvParamsBase params) {
+    constexpr int kWidth = Ktraits::kWidth;
+    constexpr int kNThreads = Ktraits::kNThreads;
+    constexpr int kNElts = Ktraits::kNElts;
+    constexpr int kNWarp = Ktraits::kNWarps;
+    constexpr int kNThreadsPerC = Ktraits::kNThreadsPerRow;
+    constexpr int kLPerLoad = Ktraits::kNColsPerLoad;
+    constexpr int kChunkSizeL = Ktraits::kChunkSizeL;
+    constexpr int kChunkSizeC = Ktraits::kNEltsPerRow;
+    using input_t = typename Ktraits::input_t;
+    using vec_t = typename Ktraits::vec_t;
+    using weight_t = typename Ktraits::weight_t;
+
+    // Shared memory.
+    __shared__ input_t x_smem[kWidth - 1 + kChunkSizeL][kChunkSizeC + kNElts];
+
+    const int batch_id = blockIdx.x;
+    const int chunk_l_id = blockIdx.y;
+    const int chunk_c_id = blockIdx.z;
+    const int tid = threadIdx.x;
+    const int l_idx = tid / kNThreadsPerC;
+    const int c_idx = tid % kNThreadsPerC;
+    input_t *x = reinterpret_cast<input_t *>(params.x_ptr) + batch_id * params.x_batch_stride
+        + (chunk_l_id * kChunkSizeL + l_idx) * params.x_l_stride + chunk_c_id * kChunkSizeC + c_idx * kNElts;
+    weight_t *weight = reinterpret_cast<weight_t *>(params.weight_ptr)
+        + chunk_c_id * kChunkSizeC * params.weight_c_stride;
+    input_t *out = reinterpret_cast<input_t *>(params.out_ptr) + batch_id * params.out_batch_stride
+        + (chunk_l_id * kChunkSizeL + l_idx) * params.out_l_stride + chunk_c_id * kChunkSizeC + c_idx * kNElts;
+    int *seq_idx = !kHasSeqIdx ? nullptr : reinterpret_cast<int *>(params.seq_idx_ptr)
+        + batch_id * params.seqlen + chunk_l_id * kChunkSizeL;
+    input_t *initial_states = params.initial_states_ptr == nullptr || chunk_l_id > 0 ? nullptr
+        : reinterpret_cast<input_t *>(params.initial_states_ptr) + batch_id * params.initial_states_batch_stride + l_idx * params.initial_states_l_stride + chunk_c_id * kChunkSizeC + c_idx * kNElts;
+    // The last L-chunk will also have enough info to write to final states, since it also contain a few x values
+    // from the previous L-chunk.
+    input_t *final_states = params.final_states_ptr == nullptr || chunk_l_id < gridDim.y - 1 ? nullptr
+        : reinterpret_cast<input_t *>(params.final_states_ptr) + batch_id * params.final_states_batch_stride + l_idx * params.final_states_l_stride + chunk_c_id * kChunkSizeC + c_idx * kNElts;
+
+    #pragma unroll
+    for (int l = 0; l < Ktraits::kNLoads; ++l) {
+        input_t x_vals_load[kNElts] = {0};
+        if (chunk_l_id * kChunkSizeL + l * kLPerLoad + l_idx < params.seqlen
+            && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+            reinterpret_cast<vec_t *>(x_vals_load)[0] = *reinterpret_cast<vec_t *>(x + l * kLPerLoad * params.x_l_stride);
+        }
+        reinterpret_cast<vec_t *>(x_smem[kWidth - 1 + l * kLPerLoad + l_idx])[c_idx] = reinterpret_cast<vec_t *>(x_vals_load)[0];
+    }
+    // Load the elements from the previous chunk that are needed for convolution.
+    if (l_idx < kWidth - 1) {
+        input_t x_vals_load[kNElts] = {0};
+        if (chunk_l_id * kChunkSizeL + l_idx - (kWidth - 1) >= 0
+            && chunk_l_id * kChunkSizeL + l_idx - (kWidth - 1) < params.seqlen
+            && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+            reinterpret_cast<vec_t *>(x_vals_load)[0] = *reinterpret_cast<vec_t *>(x - (kWidth - 1) * params.x_l_stride);
+        } else if (initial_states != nullptr
+                   && chunk_l_id * kChunkSizeL + l_idx - (kWidth - 1) < 0
+                   && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+            reinterpret_cast<vec_t *>(x_vals_load)[0] = *reinterpret_cast<vec_t *>(initial_states);
+        }
+        reinterpret_cast<vec_t *>(x_smem[l_idx])[c_idx] = reinterpret_cast<vec_t *>(x_vals_load)[0];
+    }
+
+    __syncthreads();
+
+    if (final_states != nullptr
+        && l_idx < kWidth - 1
+        && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+        // x_smem[0] contains element at index chunk_l_id * kChunkSizeL - (kWidth - 1)
+        // So last few elements (index params.seqlen - kWidth + 1 + l_idx) are stored in x_smem[params.seqlen - kWidth + 1 + l_idx - (chunk_l_id * kChunkSizeL - kWidth + 1)][c_idx]
+        *reinterpret_cast<vec_t *>(final_states) = reinterpret_cast<vec_t *>(x_smem[params.seqlen + l_idx - chunk_l_id * kChunkSizeL])[c_idx];
+    }
+
+    constexpr int kLPerThread = constexpr_min(kChunkSizeL * kChunkSizeC / kNThreads, kChunkSizeL);
+    static_assert(kLPerThread * kNThreads == kChunkSizeL * kChunkSizeC);
+    constexpr int kNThreadsPerRow = kChunkSizeL / kLPerThread;
+    static_assert(kNThreadsPerRow * kLPerThread == kChunkSizeL);
+    // kChunkSizeL, kLPerThread, kNThreadsPerRow should be powers of 2 for simplicity
+    static_assert((kChunkSizeL & (kChunkSizeL - 1)) == 0);
+    static_assert((kLPerThread & (kLPerThread - 1)) == 0);
+    static_assert((kNThreadsPerRow & (kNThreadsPerRow - 1)) == 0);
+    static_assert(kNThreadsPerRow <= 32);
+
+    const int row_idx = tid / kNThreadsPerRow;
+    const int col_idx = tid % kNThreadsPerRow;
+
+    float bias_val = params.bias_ptr == nullptr || chunk_c_id * kChunkSizeC + row_idx >= params.dim ? 0.f : float(reinterpret_cast<weight_t *>(params.bias_ptr)[chunk_c_id * kChunkSizeC + row_idx]);
+    float weight_vals[kWidth] = {0};
+    if (chunk_c_id * kChunkSizeC + row_idx < params.dim) {
+        #pragma unroll
+        for (int w = 0; w < kWidth; ++w) {
+            weight_vals[w] = weight[row_idx * params.weight_c_stride + w * params.weight_width_stride];
+        }
+    }
+    float x_vals[kWidth - 1 + kLPerThread];
+    #pragma unroll
+    for (int i = 0; i < kWidth - 1 + kLPerThread; ++i) {
+        x_vals[i] = float(x_smem[col_idx * kLPerThread + i][row_idx]);
+    }
+    int seq_idx_thread[kWidth - 1 + kLPerThread];
+    if constexpr (kHasSeqIdx) {
+        #pragma unroll
+        for (int i = 0; i < kWidth - 1 + kLPerThread; ++i) {
+            seq_idx_thread[i] = chunk_l_id * kChunkSizeL + col_idx * kLPerThread + i - (kWidth - 1) >= 0 ? seq_idx[col_idx * kLPerThread + i - (kWidth - 1)] : -1;
+        }
+    }
+
+    float out_vals[kLPerThread];
+    #pragma unroll
+    for (int i = 0; i < kLPerThread; ++i) {
+        out_vals[i] = bias_val;
+        const int seq_idx_cur = !kHasSeqIdx ? 0 : seq_idx_thread[i + kWidth - 1];
+        #pragma unroll
+        for (int w = 0; w < kWidth; ++w) {
+            if constexpr (!kHasSeqIdx) {
+                out_vals[i] += weight_vals[w] * x_vals[i + w];
+            } else {
+                out_vals[i] += seq_idx_thread[i + w] == seq_idx_cur ? weight_vals[w] * x_vals[i + w] : 0.f;
+            }
+        }
+        if (params.silu_activation) {out_vals[i] = out_vals[i] / (1 + expf(-out_vals[i])); }
+    }
+
+    __syncthreads();
+    #pragma unroll
+    for (int i = 0; i < kLPerThread; ++i) { x_smem[col_idx * kLPerThread + i][row_idx] = out_vals[i]; }
+    __syncthreads();
+
+    #pragma unroll
+    for (int l = 0; l < Ktraits::kNLoads; ++l) {
+        input_t out_vals_store[kNElts];
+        reinterpret_cast<vec_t *>(out_vals_store)[0] = reinterpret_cast<vec_t *>(x_smem[l * kLPerLoad + l_idx])[c_idx];
+        if (chunk_l_id * kChunkSizeL + l * kLPerLoad + l_idx < params.seqlen
+            && chunk_c_id * kChunkSizeC + c_idx * kNElts < params.dim) {
+            *reinterpret_cast<vec_t *>(out + l * kLPerLoad * params.out_l_stride) = reinterpret_cast<vec_t *>(out_vals_store)[0];
+        }
+    }
+
+}
+
+template<int kNThreads, int kWidth, typename input_t, typename weight_t>
+void causal_conv1d_channellast_fwd_launch(ConvParamsBase &params, cudaStream_t stream) {
+    BOOL_SWITCH(params.seq_idx_ptr != nullptr, kHasSeqIdx, [&] {
+        using Ktraits = Causal_conv1d_channellast_fwd_kernel_traits<kNThreads, kWidth, 64, true, input_t, weight_t>;
+        // constexpr int kSmemSize = Ktraits::kSmemSize;
+        constexpr int kChunkSizeL = Ktraits::kChunkSizeL;
+        constexpr int kChunkSizeC = Ktraits::kNEltsPerRow;
+        const int n_chunks_L = (params.seqlen + kChunkSizeL - 1) / kChunkSizeL;
+        const int n_chunks_C = (params.dim + kChunkSizeC - 1) / kChunkSizeC;
+        dim3 grid(params.batch, n_chunks_L, n_chunks_C);
+        dim3 block(Ktraits::kNThreads);
+        auto kernel = &causal_conv1d_channellast_fwd_kernel<Ktraits, kHasSeqIdx>;
+        // if (kSmemSize >= 48 * 1024) {
+        //     C10_CUDA_CHECK(cudaFuncSetAttribute(
+        //         kernel, cudaFuncAttributeMaxDynamicSharedMemorySize, kSmemSize));
+        //     }
+        // kernel<<<grid, Ktraits::kNThreads, kSmemSize, stream>>>(params);
+        kernel<<<grid, Ktraits::kNThreads, 0, stream>>>(params);
+        C10_CUDA_KERNEL_LAUNCH_CHECK();
+    });
+}
+
+template<typename input_t, typename weight_t>
+void causal_conv1d_channellast_fwd_cuda(ConvParamsBase &params, cudaStream_t stream) {
+    if (params.width == 2) {
+        causal_conv1d_channellast_fwd_launch<128, 2, input_t, weight_t>(params, stream);
+    } else if (params.width == 3) {
+        causal_conv1d_channellast_fwd_launch<128, 3, input_t, weight_t>(params, stream);
+    } else if (params.width == 4) {
+        causal_conv1d_channellast_fwd_launch<128, 4, input_t, weight_t>(params, stream);
+    }
+}
+
+template void causal_conv1d_fwd_cuda<float, float>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_fwd_cuda<at::Half, float>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_fwd_cuda<at::BFloat16, float>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_fwd_cuda<float, at::Half>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_fwd_cuda<at::Half, at::Half>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_fwd_cuda<at::BFloat16, at::Half>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_fwd_cuda<float, at::BFloat16>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_fwd_cuda<at::Half, at::BFloat16>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_fwd_cuda<at::BFloat16, at::BFloat16>(ConvParamsBase &params, cudaStream_t stream);
+
+template void causal_conv1d_channellast_fwd_cuda<float, float>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_channellast_fwd_cuda<at::Half, float>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_channellast_fwd_cuda<at::BFloat16, float>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_channellast_fwd_cuda<float, at::Half>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_channellast_fwd_cuda<at::Half, at::Half>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_channellast_fwd_cuda<at::BFloat16, at::Half>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_channellast_fwd_cuda<float, at::BFloat16>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_channellast_fwd_cuda<at::Half, at::BFloat16>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_channellast_fwd_cuda<at::BFloat16, at::BFloat16>(ConvParamsBase &params, cudaStream_t stream);

causal-conv1d/causal_conv1d_update.cu

@@ -0,0 +1,137 @@
+/******************************************************************************
+ * Copyright (c) 2023, Tri Dao.
+ ******************************************************************************/
+
+#include <c10/util/BFloat16.h>
+#include <c10/util/Half.h>
+#include <c10/cuda/CUDAException.h>  // For C10_CUDA_CHECK and C10_CUDA_KERNEL_LAUNCH_CHECK
+
+#include "causal_conv1d.h"
+#include "causal_conv1d_common.h"
+#include "static_switch.h"
+
+template<int kNThreads_, int kWidth_, typename input_t_, typename weight_t_>
+struct Causal_conv1d_update_kernel_traits {
+    using input_t = input_t_;
+    using weight_t = weight_t_;
+    static constexpr int kNThreads = kNThreads_;
+    static constexpr int kWidth = kWidth_;
+    static constexpr int kNBytes = sizeof(input_t);
+    static_assert(kNBytes == 2 || kNBytes == 4);
+};
+
+template<typename Ktraits, bool kIsCircularBuffer>
+__global__ __launch_bounds__(Ktraits::kNThreads)
+void causal_conv1d_update_kernel(ConvParamsBase params) {
+    constexpr int kWidth = Ktraits::kWidth;
+    constexpr int kNThreads = Ktraits::kNThreads;
+    using input_t = typename Ktraits::input_t;
+    using weight_t = typename Ktraits::weight_t;
+
+    const int tidx = threadIdx.x;
+    const int batch_id = blockIdx.x;
+    const int channel_id = blockIdx.y * kNThreads + tidx;
+    if (channel_id >= params.dim) return;
+
+    input_t *x = reinterpret_cast<input_t *>(params.x_ptr) + batch_id * params.x_batch_stride
+        + channel_id * params.x_c_stride;
+
+    // If params.conv_state_batch_indices is set, then the conv state is gathered from the conv state tensor
+    // along the batch axis. Otherwise, the conv state coordinate is the same as the batch id.
+    const int conv_state_batch_coord = params.conv_state_indices_ptr == nullptr
+        ? batch_id
+        : params.conv_state_indices_ptr[batch_id];
+    input_t *conv_state = reinterpret_cast<input_t *>(params.conv_state_ptr) 
+        + conv_state_batch_coord * params.conv_state_batch_stride
+        + channel_id * params.conv_state_c_stride;
+    weight_t *weight = reinterpret_cast<weight_t *>(params.weight_ptr) + channel_id * params.weight_c_stride;
+    input_t *out = reinterpret_cast<input_t *>(params.out_ptr) + batch_id * params.out_batch_stride
+        + channel_id * params.out_c_stride;
+    float bias_val = params.bias_ptr == nullptr ? 0.f : float(reinterpret_cast<weight_t *>(params.bias_ptr)[channel_id]);
+
+    int state_len = params.conv_state_len;
+    int advance_len = params.seqlen;
+    int cache_seqlen = kIsCircularBuffer ? params.cache_seqlens[batch_id] % state_len : 0;
+    int update_idx = cache_seqlen - (kWidth - 1);
+    update_idx = update_idx < 0 ? update_idx + state_len : update_idx;
+
+    float weight_vals[kWidth] = {0};
+    #pragma unroll
+    for (int i = 0; i < kWidth; ++i) { weight_vals[i] = float(weight[i * params.weight_width_stride]); }
+
+    float x_vals[kWidth] = {0};
+    if constexpr (!kIsCircularBuffer) {
+        #pragma unroll 2
+        for (int i = 0; i < state_len - advance_len - (kWidth - 1); ++i) {
+            conv_state[i * params.conv_state_l_stride] = conv_state[(i + advance_len) * params.conv_state_l_stride];
+        }
+        #pragma unroll
+        for (int i = 0; i < kWidth - 1; ++i) {
+            input_t state_val = conv_state[(state_len - (kWidth - 1) + i) * params.conv_state_l_stride];
+            if (i < advance_len + (kWidth - 1) && state_len - advance_len - (kWidth - 1) + i >= 0) {
+                conv_state[(state_len - advance_len - (kWidth - 1) + i) * params.conv_state_l_stride] = state_val;
+            }
+            x_vals[i] = float(state_val);
+        }
+    } else {
+        #pragma unroll
+        for (int i = 0; i < kWidth - 1; ++i, update_idx = update_idx + 1 >= state_len ? update_idx + 1 - state_len : update_idx + 1) {
+            input_t state_val = conv_state[update_idx * params.conv_state_l_stride];
+            x_vals[i] = float(state_val);
+        }
+    }
+    #pragma unroll 2
+    for (int i = 0; i < params.seqlen; ++i) {
+        input_t x_val = x[i * params.x_l_stride];
+        if constexpr (!kIsCircularBuffer) {
+            if (i < advance_len && state_len - advance_len + i >= 0) {
+                conv_state[(state_len - advance_len + i) * params.conv_state_l_stride] = x_val;
+            }
+        } else {
+            conv_state[update_idx * params.conv_state_l_stride] = x_val;
+            ++update_idx;
+            update_idx = update_idx >= state_len ? update_idx - state_len : update_idx;
+        }
+        x_vals[kWidth - 1] = float(x_val);
+        float out_val = bias_val;
+        #pragma unroll
+        for (int j = 0; j < kWidth; ++j) { out_val += weight_vals[j] * x_vals[j]; }
+        if (params.silu_activation) { out_val = out_val / (1 + expf(-out_val)); }
+        out[i * params.out_l_stride] = input_t(out_val);
+        // Shift the input buffer by 1
+        #pragma unroll
+        for (int i = 0; i < kWidth - 1; ++i) { x_vals[i] = x_vals[i + 1]; }
+    }
+}
+
+template<int kNThreads, int kWidth, typename input_t, typename weight_t>
+void causal_conv1d_update_launch(ConvParamsBase &params, cudaStream_t stream) {
+    using Ktraits = Causal_conv1d_update_kernel_traits<kNThreads, kWidth, input_t, weight_t>;
+    dim3 grid(params.batch, (params.dim + kNThreads - 1) / kNThreads);
+    auto kernel = params.cache_seqlens == nullptr
+        ? &causal_conv1d_update_kernel<Ktraits, false>
+        : &causal_conv1d_update_kernel<Ktraits, true>;
+    kernel<<<grid, Ktraits::kNThreads, 0, stream>>>(params);
+    C10_CUDA_KERNEL_LAUNCH_CHECK();
+}
+
+template<typename input_t, typename weight_t>
+void causal_conv1d_update_cuda(ConvParamsBase &params, cudaStream_t stream) {
+    if (params.width == 2) {
+        causal_conv1d_update_launch<64, 2, input_t, weight_t>(params, stream);
+    } else if (params.width == 3) {
+        causal_conv1d_update_launch<64, 3, input_t, weight_t>(params, stream);
+    } else if (params.width == 4) {
+        causal_conv1d_update_launch<64, 4, input_t, weight_t>(params, stream);
+    }
+}
+
+template void causal_conv1d_update_cuda<float, float>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_update_cuda<at::Half, float>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_update_cuda<at::BFloat16, float>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_update_cuda<float, at::Half>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_update_cuda<at::Half, at::Half>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_update_cuda<at::BFloat16, at::Half>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_update_cuda<float, at::BFloat16>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_update_cuda<at::Half, at::BFloat16>(ConvParamsBase &params, cudaStream_t stream);
+template void causal_conv1d_update_cuda<at::BFloat16, at::BFloat16>(ConvParamsBase &params, cudaStream_t stream);

causal-conv1d/static_switch.h

@@ -0,0 +1,25 @@
+// Inspired by https://github.com/NVIDIA/DALI/blob/main/include/dali/core/static_switch.h
+// and https://github.com/pytorch/pytorch/blob/master/aten/src/ATen/Dispatch.h
+
+#pragma once
+
+/// @param COND       - a boolean expression to switch by
+/// @param CONST_NAME - a name given for the constexpr bool variable.
+/// @param ...       - code to execute for true and false
+///
+/// Usage:
+/// ```
+/// BOOL_SWITCH(flag, BoolConst, [&] {
+///     some_function<BoolConst>(...);
+/// });
+/// ```
+#define BOOL_SWITCH(COND, CONST_NAME, ...)                                           \
+    [&] {                                                                            \
+        if (COND) {                                                                  \
+            static constexpr bool CONST_NAME = true;                                 \
+            return __VA_ARGS__();                                                    \
+        } else {                                                                     \
+            static constexpr bool CONST_NAME = false;                                \
+            return __VA_ARGS__();                                                    \
+        }                                                                            \
+    }()

flake.lock

@@ -0,0 +1,168 @@
+{
+  "nodes": {
+    "flake-compat": {
+      "locked": {
+        "lastModified": 1747046372,
+        "narHash": "sha256-CIVLLkVgvHYbgI2UpXvIIBJ12HWgX+fjA8Xf8PUmqCY=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "9100a0f413b0c601e0533d1d94ffd501ce2e7885",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "flake-compat_2": {
+      "locked": {
+        "lastModified": 1733328505,
+        "narHash": "sha256-NeCCThCEP3eCl2l/+27kNNK7QrwZB1IJCrXfrbv5oqU=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "ff81ac966bb2cae68946d5ed5fc4994f96d0ffec",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_2"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "hf-nix": {
+      "inputs": {
+        "flake-compat": "flake-compat_2",
+        "flake-utils": "flake-utils_2",
+        "nixpkgs": "nixpkgs"
+      },
+      "locked": {
+        "lastModified": 1754038838,
+        "narHash": "sha256-oHigCT4z0ayyLyEuxdZooSXRAZP8lfOkZHzY1lx1U50=",
+        "owner": "huggingface",
+        "repo": "hf-nix",
+        "rev": "336f781fa284e193baa3d4c3ce3f95fb34e9ffad",
+        "type": "github"
+      },
+      "original": {
+        "owner": "huggingface",
+        "repo": "hf-nix",
+        "type": "github"
+      }
+    },
+    "kernel-builder": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "flake-utils": "flake-utils",
+        "hf-nix": "hf-nix",
+        "nixpkgs": [
+          "kernel-builder",
+          "hf-nix",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1755181472,
+        "narHash": "sha256-xOXjhehC5xi/XB4fXZ5c0L2sSyDjJQdlH7/BcdHLBaM=",
+        "owner": "huggingface",
+        "repo": "kernel-builder",
+        "rev": "85da46f660c1c43b40771c3df3b223bb3fa39bec",
+        "type": "github"
+      },
+      "original": {
+        "owner": "huggingface",
+        "repo": "kernel-builder",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1752785354,
+        "narHash": "sha256-Y33ryUz7MPqKrZwlbQcsYCUz2jAJCacRf8jbs0tYUlA=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "d38025438a6ee456758dc03188ca6873a415463b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "d38025438a6ee456758dc03188ca6873a415463b",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "kernel-builder": "kernel-builder"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,18 @@
+{
+  description = "Flake for attention kernels";
+
+  inputs = {
+    kernel-builder.url = "github:huggingface/kernel-builder";
+  };
+
+  outputs =
+    {
+      self,
+      kernel-builder,
+    }:
+    kernel-builder.lib.genFlakeOutputs {
+      path = ./.;
+      rev = self.shortRev or self.dirtyShortRev or self.lastModifiedDate;
+      pythonCheckInputs = pkgs: with pkgs; [ einops ];
+    };
+}

tests/test_causal_conv1d.py

@@ -0,0 +1,353 @@
+# Copyright (C) 2024, Tri Dao.
+
+import math
+
+import torch
+import torch.nn.functional as F
+
+import pytest
+
+from einops import rearrange
+
+
+from causal_conv1d import causal_conv1d_fn, causal_conv1d_update, causal_conv1d_varlen_states
+from causal_conv1d.causal_conv1d_interface import causal_conv1d_ref
+from causal_conv1d.causal_conv1d_interface import causal_conv1d_update_ref
+from causal_conv1d.causal_conv1d_varlen import causal_conv1d_varlen_states_ref
+
+
+@pytest.mark.parametrize("return_final_states", [False, True])
+# @pytest.mark.parametrize("return_final_states", [True])
+@pytest.mark.parametrize("has_initial_states", [False, True])
+# @pytest.mark.parametrize("has_initial_states", [False])
+@pytest.mark.parametrize("channel_last", [False, True])
+# @pytest.mark.parametrize('channel_last', [True])
+@pytest.mark.parametrize("itype", [torch.float32, torch.float16, torch.bfloat16])
+# @pytest.mark.parametrize('itype', [torch.float16])
+@pytest.mark.parametrize("silu_activation", [False, True])
+# @pytest.mark.parametrize('silu_activation', [True])
+@pytest.mark.parametrize("has_bias", [False, True])
+# @pytest.mark.parametrize('has_bias', [True])
+@pytest.mark.parametrize("width", [2, 3, 4])
+# @pytest.mark.parametrize('width', [3])
+@pytest.mark.parametrize(
+    "seqlen", [1, 2, 8, 16, 32, 64, 128, 129, 130, 151, 256, 372, 512, 784, 1024, 1134, 2048, 4096]
+)
+# @pytest.mark.parametrize('seqlen', [8, 16, 32, 64, 128, 256, 512, 784, 1024, 2048, 4096])
+# @pytest.mark.parametrize('seqlen', [128])
+@pytest.mark.parametrize('dim', [64, 4096 + 32])
+# @pytest.mark.parametrize('dim', [64])
+def test_causal_conv1d(dim, seqlen, width, has_bias, silu_activation, itype, channel_last, has_initial_states, return_final_states):
+    if not channel_last and (has_initial_states or return_final_states):
+        pytest.skip("Only channel_last support initial_states or return_final_states")
+    device = "cuda"
+    rtol, atol = (3e-4, 1e-3) if itype == torch.float32 else (3e-3, 5e-3)
+    if itype == torch.bfloat16:
+        rtol, atol = 1e-2, 5e-2
+    rtolw, atolw = (1e-3, 1e-3)
+    # set seed
+    torch.random.manual_seed(0)
+    batch = 2
+    # batch = 1
+    if not channel_last:
+        x = torch.randn(batch, 4096 + dim + 64, seqlen, device=device, dtype=itype)[:, 4096:4096 + dim, :].requires_grad_()
+    else:
+        x = rearrange(
+            torch.randn(batch, seqlen, 4096 + dim + 64, device=device, dtype=itype)[:, :, 4096:4096 + dim], "b s d -> b d s"
+        ).requires_grad_()
+    weight = torch.randn(dim, width, device=device, dtype=torch.float32, requires_grad=True)
+    if has_bias:
+        bias = torch.randn(dim, device=device, dtype=torch.float32, requires_grad=True)
+    else:
+        bias = None
+    if has_initial_states:
+        initial_states = torch.randn(batch, width - 1, dim, device=device, dtype=itype).transpose(1, 2).requires_grad_()
+    else:
+        initial_states = None
+    x_ref = x.detach().clone().requires_grad_()
+    weight_ref = weight.detach().clone().requires_grad_()
+    bias_ref = bias.detach().clone().requires_grad_() if bias is not None else None
+    initial_states_ref = initial_states.detach().clone().requires_grad_() if initial_states is not None else None
+    activation = None if not silu_activation else "silu"
+    out = causal_conv1d_fn(x, weight, bias, initial_states=initial_states, return_final_states=return_final_states,
+                           activation=activation)
+    out_ref = causal_conv1d_ref(x_ref, weight_ref, bias_ref, initial_states=initial_states_ref, return_final_states=return_final_states, activation=activation)
+    if return_final_states:
+        out, final_states = out
+        out_ref, final_states_ref = out_ref
+        print(f"Final states max diff: {(final_states - final_states_ref).abs().max().item()}")
+        print(f"Final states mean diff: {(final_states - final_states_ref).abs().mean().item()}")
+        assert torch.allclose(final_states, final_states_ref, rtol=rtol, atol=atol)
+
+    print(f"Output max diff: {(out - out_ref).abs().max().item()}")
+    print(f"Output mean diff: {(out - out_ref).abs().mean().item()}")
+    assert torch.allclose(out, out_ref, rtol=rtol, atol=atol)
+
+    if return_final_states:
+        out += F.sigmoid(final_states).sum(dim=-1, keepdim=True)
+        out_ref += F.sigmoid(final_states_ref).sum(dim=-1, keepdim=True)
+
+    g = torch.randn_like(out)
+    out.backward(g)
+    out_ref.backward(g)
+
+    print(f"dx max diff: {(x.grad - x_ref.grad).abs().max().item()}")
+    print(f"dweight max diff: {(weight.grad - weight_ref.grad).abs().max().item()}")
+    if has_bias:
+        print(f"dbias max diff: {(bias.grad - bias_ref.grad).abs().max().item()}")
+    if has_initial_states:
+        print(f"dinitial_states max diff: {(initial_states.grad - initial_states_ref.grad).abs().max().item()}")
+
+    assert torch.allclose(x.grad, x_ref.grad.to(dtype=itype), rtol=rtol, atol=atol)
+    assert torch.allclose(weight.grad, weight_ref.grad, rtol=rtolw, atol=atolw)
+    if has_bias:
+        assert torch.allclose(bias.grad, bias_ref.grad, rtol=rtolw, atol=atolw)
+    if has_initial_states:
+        assert torch.allclose(initial_states.grad, initial_states_ref.grad.to(dtype=itype), rtol=rtol, atol=atol)
+
+
+@pytest.mark.parametrize("itype", [torch.float32, torch.float16, torch.bfloat16])
+# @pytest.mark.parametrize('itype', [torch.float16])
+@pytest.mark.parametrize("silu_activation", [False, True])
+# @pytest.mark.parametrize('silu_activation', [True])
+@pytest.mark.parametrize("has_bias", [False, True])
+# @pytest.mark.parametrize('has_bias', [True])
+@pytest.mark.parametrize("has_cache_seqlens", [False, True])
+# @pytest.mark.parametrize('has_cache_seqlens', [True])
+@pytest.mark.parametrize("seqlen", [1, 4, 5])
+# @pytest.mark.parametrize('seqlen', [4])
+@pytest.mark.parametrize("width", [2, 3, 4])
+# @pytest.mark.parametrize('width', [4])
+@pytest.mark.parametrize("dim", [2048, 2048 + 16, 4096])
+# @pytest.mark.parametrize("dim", [2048])
+def test_causal_conv1d_update(dim, width, seqlen, has_cache_seqlens, has_bias, silu_activation, itype):
+    device = "cuda"
+    rtol, atol = (3e-4, 1e-3) if itype == torch.float32 else (3e-3, 5e-3)
+    if itype == torch.bfloat16:
+        rtol, atol = 1e-2, 5e-2
+    rtolw, atolw = (1e-3, 1e-3)
+    # set seed
+    torch.random.manual_seed(0)
+    batch = 64
+    # batch = 1
+    # dim = 64
+    x = torch.randn(batch, seqlen, dim, device=device, dtype=itype).transpose(-1, -2)
+    state_len = torch.randint(width - 1, width + 10, (1,)).item()
+    conv_state = torch.randn(batch, state_len, dim, device=device, dtype=itype).transpose(-1, -2)
+    weight = torch.randn(dim, width, device=device, dtype=torch.float32, requires_grad=True)
+    if has_bias:
+        bias = torch.randn(dim, device=device, dtype=torch.float32, requires_grad=True)
+    else:
+        bias = None
+    conv_state_ref = conv_state.detach().clone()
+    activation = None if not silu_activation else "silu"
+    cache_seqlens = (torch.randint(0, 1024, (batch,), dtype=torch.int32, device=device)
+                     if has_cache_seqlens else None)
+    out = causal_conv1d_update(x, conv_state, weight, bias, activation=activation, cache_seqlens=cache_seqlens)
+    out_ref = causal_conv1d_update_ref(x, conv_state_ref, weight, bias, activation=activation, cache_seqlens=cache_seqlens)
+
+    print(f"Output max diff: {(out - out_ref).abs().max().item()}")
+    print(f"Output mean diff: {(out - out_ref).abs().mean().item()}")
+    assert torch.equal(conv_state, conv_state_ref)
+    assert torch.allclose(out, out_ref, rtol=rtol, atol=atol)
+
+@pytest.mark.parametrize("itype", [torch.float32, torch.float16, torch.bfloat16])
+# @pytest.mark.parametrize('itype', [torch.float16])
+@pytest.mark.parametrize("silu_activation", [False, True])
+# @pytest.mark.parametrize('silu_activation', [True])
+@pytest.mark.parametrize("has_bias", [False, True])
+# @pytest.mark.parametrize('has_bias', [True])
+@pytest.mark.parametrize("has_cache_seqlens", [False, True])
+# @pytest.mark.parametrize('has_cache_seqlens', [True])
+@pytest.mark.parametrize("seqlen", [1, 4, 5])
+# @pytest.mark.parametrize('seqlen', [4])
+@pytest.mark.parametrize("width", [2, 3, 4])
+# @pytest.mark.parametrize('width', [4])
+@pytest.mark.parametrize("dim", [2048, 2048 + 16, 4096])
+# @pytest.mark.parametrize("dim", [2048])
+def test_causal_conv1d_update_with_batch_gather(dim, width, seqlen, has_cache_seqlens, has_bias, silu_activation, itype):
+    device = "cuda"
+    rtol, atol = (3e-4, 1e-3) if itype == torch.float32 else (3e-3, 5e-3)
+    if itype == torch.bfloat16:
+        rtol, atol = 1e-2, 5e-2
+    rtolw, atolw = (1e-3, 1e-3)
+    # set seed
+    torch.random.manual_seed(0)
+    batch = 64
+    # batch = 1
+    # dim = 64
+    x = torch.randn(batch, seqlen, dim, device=device, dtype=itype).transpose(-1, -2)
+    state_len = torch.randint(width - 1, width + 10, (1,)).item()
+
+    total_entries = 10 * batch
+    conv_state = torch.randn(total_entries, state_len, dim, device=device, dtype=itype).transpose(-1, -2)
+    conv_state_indices = torch.randperm(total_entries)[:batch].to(dtype=torch.int32, device=device)
+
+    weight = torch.randn(dim, width, device=device, dtype=torch.float32, requires_grad=True)
+    if has_bias:
+        bias = torch.randn(dim, device=device, dtype=torch.float32, requires_grad=True)
+    else:
+        bias = None
+    conv_state_ref = conv_state[conv_state_indices, :].detach().clone()
+    activation = None if not silu_activation else "silu"
+    cache_seqlens = (torch.randint(0, 1024, (batch,), dtype=torch.int32, device=device)
+                     if has_cache_seqlens else None)
+    out = causal_conv1d_update(x, conv_state, weight, bias, activation=activation,
+                               cache_seqlens=cache_seqlens, conv_state_indices=conv_state_indices)
+    out_ref = causal_conv1d_update_ref(x, conv_state_ref, weight, bias, activation=activation, cache_seqlens=cache_seqlens)
+
+    print(f"Output max diff: {(out - out_ref).abs().max().item()}")
+    print(f"Output mean diff: {(out - out_ref).abs().mean().item()}")
+    assert torch.equal(conv_state[conv_state_indices, :], conv_state_ref)
+    assert torch.allclose(out, out_ref, rtol=rtol, atol=atol)
+
+
+@pytest.mark.parametrize("itype", [torch.float32, torch.float16, torch.bfloat16])
+# @pytest.mark.parametrize('itype', [torch.float16])
+@pytest.mark.parametrize("dim", [2048, 2048 + 16, 4096])
+# @pytest.mark.parametrize("dim", [2048])
+def test_causal_conv1d_get_states(dim, itype):
+    device = "cuda"
+    # set seed
+    torch.random.manual_seed(0)
+    seqlens = torch.randint(1, 32, (100,), device=device)
+    total_seqlen = seqlens.sum().item()
+    x = torch.randn(total_seqlen, dim, device=device, dtype=itype)
+    cu_seqlens = F.pad(seqlens.cumsum(0), (1, 0))
+    state_len = 20
+    out = causal_conv1d_varlen_states(x, cu_seqlens, state_len)
+    out_ref = causal_conv1d_varlen_states_ref(x, cu_seqlens, state_len)
+    assert torch.equal(out, out_ref)
+
+
+# @pytest.mark.parametrize("channel_last", [False, True])
+@pytest.mark.parametrize('channel_last', [True])
+# @pytest.mark.parametrize("itype", [torch.float32, torch.float16, torch.bfloat16])
+@pytest.mark.parametrize('itype', [torch.bfloat16])
+# @pytest.mark.parametrize("silu_activation", [False, True])
+@pytest.mark.parametrize('silu_activation', [True])
+# @pytest.mark.parametrize("has_bias", [False, True])
+@pytest.mark.parametrize('has_bias', [True])
+# @pytest.mark.parametrize("width", [2, 3, 4])
+@pytest.mark.parametrize('width', [4])
+@pytest.mark.parametrize(
+    # "seqlen", [8, 16, 32, 64, 128, 151, 256, 372, 512, 784, 1024, 1134, 2048, 4096]
+    "seqlen", [2048]
+)
+# @pytest.mark.parametrize('seqlen', [8, 16, 32, 64, 128, 256, 512, 784, 1024, 2048, 4096])
+# @pytest.mark.parametrize('seqlen', [128])
+def test_causal_conv1d_race_condition(seqlen, width, has_bias, silu_activation, itype, channel_last):
+    device = "cuda"
+    # set seed
+    torch.random.manual_seed(0)
+    batch = 2
+    # batch = 1
+    dim = 4096 + 32  # Try dim not divisible by 64
+    # dim = 64
+    if not channel_last:
+        x = torch.randn(batch, 4096 + dim + 64, seqlen, device=device, dtype=itype)[:, 4096:4096 + dim, :].requires_grad_()
+    else:
+        x = rearrange(
+            torch.randn(batch, seqlen, 4096 + dim + 64, device=device, dtype=itype)[:, :, 4096:4096 + dim], "b s d -> b d s"
+        ).requires_grad_()
+    weight = torch.randn(dim, width, device=device, dtype=torch.float32, requires_grad=True)
+    if has_bias:
+        bias = torch.randn(dim, device=device, dtype=torch.float32, requires_grad=True)
+    else:
+        bias = None
+    activation = None if not silu_activation else "silu"
+    out0 = causal_conv1d_fn(x, weight, bias, activation=activation)
+    g = torch.randn_like(out0)
+    dx0, dw0, db0 = torch.autograd.grad(out0, (x, weight, bias), g)
+    dw_atol = 1e-4
+    db_atol = 1e-4
+
+    for i in range(10000):
+        out = causal_conv1d_fn(x, weight, bias, activation=activation)
+        dx, dw, db = torch.autograd.grad(out, (x, weight, bias), g)
+        dw_equal = torch.allclose(dw, dw0, atol=dw_atol)
+        # if not dw_equal:
+        #     breakpoint()
+        if has_bias:
+            db_equal = torch.allclose(db, db0, atol=db_atol)
+            # if not db_equal:
+            #     breakpoint()
+        assert torch.equal(out, out0)
+        assert torch.equal(dx, dx0)
+        assert dw_equal
+        if has_bias:
+            assert dw_equal
+
+
+@pytest.mark.parametrize("itype", [torch.float32, torch.float16, torch.bfloat16])
+# @pytest.mark.parametrize('itype', [torch.float16])
+@pytest.mark.parametrize("silu_activation", [False, True])
+# @pytest.mark.parametrize('silu_activation', [False])
+@pytest.mark.parametrize("has_bias", [False, True])
+# @pytest.mark.parametrize('has_bias', [False])
+@pytest.mark.parametrize("width", [2, 3, 4])
+# @pytest.mark.parametrize('width', [2])
+@pytest.mark.parametrize(
+    "seqlen", [8, 16, 32, 64, 128, 151, 256, 372, 512, 784, 1024, 1134, 2048, 4096]
+)
+# @pytest.mark.parametrize('seqlen', [8, 16, 32, 64, 128, 256, 512, 784, 1024, 2048, 4096])
+# @pytest.mark.parametrize('seqlen', [2048])
+@pytest.mark.parametrize('dim', [64, 4096 + 32])
+# @pytest.mark.parametrize('dim', [64])
+def test_causal_conv1d_varlen(dim, seqlen, width, has_bias, silu_activation, itype):
+    device = "cuda"
+    rtol, atol = (3e-4, 1e-3) if itype == torch.float32 else (3e-3, 5e-3)
+    if itype == torch.bfloat16:
+        rtol, atol = 1e-2, 5e-2
+    rtolw, atolw = (1e-3, 1e-3)
+    # set seed
+    torch.random.manual_seed(seqlen + dim + width)
+    batch = 3
+    seqlens = []
+    for b in range(batch):
+        nsplits = torch.randint(1, 5, (1,)).item()
+        eos_pos = torch.randperm(seqlen - 1)[:nsplits].sort().values
+        seqlens.append(torch.diff(torch.cat([torch.tensor([-1]), eos_pos, torch.tensor([seqlen - 1])])).tolist())
+        assert sum(seqlens[-1]) == seqlen
+        assert all(s > 0 for s in seqlens[-1])
+    # Only support channel_last
+    x = rearrange(
+        torch.randn(batch, seqlen, 4096 + dim + 64, device=device, dtype=itype)[:, :, 4096:4096 + dim], "b s d -> b d s"
+    ).requires_grad_()
+    weight = torch.randn(dim, width, device=device, dtype=torch.float32, requires_grad=True)
+    if has_bias:
+        bias = torch.randn(dim, device=device, dtype=torch.float32, requires_grad=True)
+    else:
+        bias = None
+    seq_idx = torch.stack([torch.cat([torch.full((s,), i, dtype=torch.int32, device=device) for i, s in enumerate(sl)], dim=0)
+                           for sl in seqlens], dim=0)
+    x_ref = x.detach().clone().requires_grad_()
+    weight_ref = weight.detach().clone().requires_grad_()
+    bias_ref = bias.detach().clone().requires_grad_() if bias is not None else None
+    activation = None if not silu_activation else "silu"
+    out = causal_conv1d_fn(x, weight, bias, seq_idx=seq_idx, activation=activation)
+    out_ref = []
+    for b in range(batch):
+        out_ref_b = []
+        for x_s in torch.split(x_ref[[b]], seqlens[b], dim=2):
+            out_ref_b.append(causal_conv1d_ref(x_s, weight_ref, bias_ref, activation=activation))
+        out_ref.append(torch.cat(out_ref_b, dim=2))
+    out_ref = torch.cat(out_ref, dim=0)
+
+    print(f"Output max diff: {(out - out_ref).abs().max().item()}")
+    print(f"Output mean diff: {(out - out_ref).abs().mean().item()}")
+    assert torch.allclose(out, out_ref, rtol=rtol, atol=atol)
+
+    g = torch.randn_like(out)
+    out_ref.backward(g)
+    out.backward(g)
+
+    print(f"dx max diff: {(x.grad - x_ref.grad).abs().max().item()}")
+    print(f"dweight max diff: {(weight.grad - weight_ref.grad).abs().max().item()}")
+    if has_bias:
+        print(f"dbias max diff: {(bias.grad - bias_ref.grad).abs().max().item()}")
+
+    assert torch.allclose(x.grad, x_ref.grad.to(dtype=itype), rtol=rtol, atol=atol)
+    assert torch.allclose(weight.grad, weight_ref.grad, rtol=rtolw, atol=atolw)
+    if has_bias:
+        assert torch.allclose(bias.grad, bias_ref.grad, rtol=rtolw, atol=atolw)

torch-ext/causal_conv1d/__init__.py

@@ -0,0 +1,4 @@
+from .causal_conv1d_interface import causal_conv1d_fn, causal_conv1d_update
+from .causal_conv1d_varlen import causal_conv1d_varlen_states
+
+__all__ = ["causal_conv1d_fn", "causal_conv1d_update", "causal_conv1d_varlen_states"]

torch-ext/causal_conv1d/causal_conv1d_interface.py

@@ -0,0 +1,242 @@
+# Copyright (c) 2024, Tri Dao.
+
+import torch
+import torch.nn.functional as F
+
+from .cpp_functions import causal_conv1d_fwd_function, causal_conv1d_bwd_function, causal_conv1d_update_function
+
+
+class CausalConv1dFn(torch.autograd.Function):
+    @staticmethod
+    def forward(
+        ctx,
+        x,
+        weight,
+        bias=None,
+        seq_idx=None,
+        initial_states=None,
+        return_final_states=False,
+        final_states_out=None,
+        activation=None,
+    ):
+        if activation not in [None, "silu", "swish"]:
+            raise NotImplementedError("activation must be None, silu, or swish")
+        if x.stride(2) != 1 and x.stride(1) != 1:
+            x = x.contiguous()
+        bias = bias.contiguous() if bias is not None else None
+        if seq_idx is not None:
+            assert (
+                initial_states is None
+            ), "initial_states must be None if seq_idx is not None"
+            assert (
+                not return_final_states
+            ), "If seq_idx is not None, we don't return final_states_out"
+        seq_idx = seq_idx.contiguous() if seq_idx is not None else None
+        if initial_states is not None and (
+            initial_states.stride(2) != 1 and initial_states.stride(1) != 1
+        ):
+            initial_states = initial_states.contiguous()
+        if return_final_states:
+            assert (
+                x.stride(1) == 1
+            ), "Only channel-last layout support returning final_states_out"
+            if final_states_out is not None:
+                assert (
+                    final_states_out.stride(2) == 1 or final_states_out.stride(1) == 1
+                )
+            else:
+                batch, dim, seqlen = x.shape
+                width = weight.shape[1]
+                final_states_out = torch.empty(
+                    batch, width - 1, dim, device=x.device, dtype=x.dtype
+                ).transpose(1, 2)
+        else:
+            final_states_out = None
+        ctx.activation = activation in ["silu", "swish"]
+        out = causal_conv1d_fwd_function(
+            x, weight, bias, seq_idx, initial_states, final_states_out, ctx.activation
+        )
+        ctx.save_for_backward(x, weight, bias, seq_idx, initial_states)
+        ctx.return_final_states = return_final_states
+        ctx.return_dinitial_states = (
+            initial_states is not None and initial_states.requires_grad
+        )
+        return out if not return_final_states else (out, final_states_out)
+
+    @staticmethod
+    def backward(ctx, dout, *args):
+        x, weight, bias, seq_idx, initial_states = ctx.saved_tensors
+        dfinal_states = args[0] if ctx.return_final_states else None
+        if dout.stride(2) != 1 and dout.stride(1) != 1:
+            dout = dout.contiguous()
+        # The kernel supports passing in a pre-allocated dx (e.g., in case we want to fuse the
+        # backward of conv1d with the backward of chunk).
+        # Here we just pass in None and dx will be allocated in the C++ code.
+        dx, dweight, dbias, dinitial_states = causal_conv1d_bwd_function(
+            x,
+            weight,
+            bias,
+            dout,
+            seq_idx,
+            initial_states,
+            dfinal_states,
+            None,
+            ctx.return_dinitial_states,
+            ctx.activation,
+        )
+        return (
+            dx,
+            dweight,
+            dbias if bias is not None else None,
+            None,
+            dinitial_states if initial_states is not None else None,
+            None,
+            None,
+            None,
+        )
+
+
+def causal_conv1d_fn(
+    x,
+    weight,
+    bias=None,
+    seq_idx=None,
+    initial_states=None,
+    return_final_states=False,
+    final_states_out=None,
+    activation=None,
+):
+    """
+    x: (batch, dim, seqlen)
+    weight: (dim, width)
+    bias: (dim,)
+    seq_idx: (batch, seqlen)
+    initial_states: (batch, dim, width - 1)
+    final_states_out: (batch, dim, width - 1), to be written to
+    activation: either None or "silu" or "swish"
+
+    out: (batch, dim, seqlen)
+    """
+    return CausalConv1dFn.apply(
+        x,
+        weight,
+        bias,
+        seq_idx,
+        initial_states,
+        return_final_states,
+        final_states_out,
+        activation,
+    )
+
+
+def causal_conv1d_ref(
+    x,
+    weight,
+    bias=None,
+    initial_states=None,
+    return_final_states=False,
+    final_states_out=None,
+    activation=None,
+):
+    """
+    x: (batch, dim, seqlen)
+    weight: (dim, width)
+    bias: (dim,)
+    initial_states: (batch, dim, width - 1)
+    final_states_out: (batch, dim, width - 1)
+
+    out: (batch, dim, seqlen)
+    """
+    if activation not in [None, "silu", "swish"]:
+        raise NotImplementedError("activation must be None, silu, or swish")
+    dtype_in = x.dtype
+    x = x.to(weight.dtype)
+    seqlen = x.shape[-1]
+    dim, width = weight.shape
+    if initial_states is None:
+        out = F.conv1d(x, weight.unsqueeze(1), bias, padding=width - 1, groups=dim)
+    else:
+        x = torch.cat([initial_states, x], dim=-1)
+        out = F.conv1d(x, weight.unsqueeze(1), bias, padding=0, groups=dim)
+    out = out[..., :seqlen]
+    if return_final_states:
+        final_states = F.pad(x, (width - 1 - x.shape[-1], 0)).to(
+            dtype_in
+        )  # (batch, dim, width - 1)
+        if final_states_out is not None:
+            final_states_out.copy_(final_states)
+        else:
+            final_states_out = final_states
+    out = (out if activation is None else F.silu(out)).to(dtype=dtype_in)
+    return out if not return_final_states else (out, final_states_out)
+
+
+def causal_conv1d_update(x, conv_state, weight, bias=None, activation=None, cache_seqlens=None, conv_state_indices=None):
+    """
+    x: (batch, dim) or (batch, dim, seqlen)
+    conv_state: (batch, dim, state_len), where state_len >= width - 1
+    weight: (dim, width)
+    bias: (dim,)
+    cache_seqlens: (batch,), dtype int32.
+        If not None, the conv_state is treated as a circular buffer.
+        The conv_state will be updated by copying x to the conv_state starting at the index
+        @cache_seqlens % state_len.
+    conv_state_indices: (batch,), dtype int32
+        If None, the conv_state is a larger tensor along the batch dim, 
+        and we are selecting the batch coords specified by conv_state_indices.
+        Useful for a continuous batching scenario.
+
+    out: (batch, dim) or (batch, dim, seqlen)
+    """
+    if activation not in [None, "silu", "swish"]:
+        raise NotImplementedError("activation must be None, silu, or swish")
+    activation = activation in ["silu", "swish"]
+    unsqueeze = x.dim() == 2
+    if unsqueeze:
+        x = x.unsqueeze(-1)
+    out = causal_conv1d_update_function(
+        x, conv_state, weight, bias, activation, cache_seqlens, conv_state_indices
+    )
+    if unsqueeze:
+        out = out.squeeze(-1)
+    return out
+
+
+def causal_conv1d_update_ref(x, conv_state, weight, bias=None, activation=None, cache_seqlens=None):
+    """
+    x: (batch, dim) or (batch, dim, seqlen)
+    conv_state: (batch, dim, state_len), where state_len >= width - 1
+    weight: (dim, width)
+    bias: (dim,)
+    cache_seqlens: (batch,), dtype int32.
+        If not None, the conv_state is treated as a circular buffer.
+        The conv_state will be updated by copying x to the conv_state starting at the index
+        @cache_seqlens % state_len before performing the convolution.
+
+    out: (batch, dim) or (batch, dim, seqlen)
+    """
+    if activation not in [None, "silu", "swish"]:
+        raise NotImplementedError("activation must be None, silu, or swish")
+    dtype_in = x.dtype
+    unsqueeze = x.dim() == 2
+    if unsqueeze:
+        x = x.unsqueeze(-1)
+    batch, dim, seqlen = x.shape
+    width = weight.shape[1]
+    state_len = conv_state.shape[-1]
+    assert conv_state.shape == (batch, dim, state_len)
+    assert weight.shape == (dim, width)
+    if cache_seqlens is None:
+        x_new = torch.cat([conv_state, x], dim=-1).to(weight.dtype)  # (batch, dim, state_len + seqlen)
+        conv_state.copy_(x_new[:, :, -state_len:])
+    else:
+        width_idx = torch.arange(-(width - 1), 0, dtype=torch.long, device=x.device).unsqueeze(0) + cache_seqlens.unsqueeze(1)
+        width_idx = torch.remainder(width_idx, state_len).unsqueeze(1).expand(-1, dim, -1)
+        x_new = torch.cat([conv_state.gather(2, width_idx), x], dim=-1).to(weight.dtype)
+        copy_idx = torch.arange(seqlen, dtype=torch.long, device=x.device).unsqueeze(0) + cache_seqlens.unsqueeze(1)
+        copy_idx = torch.remainder(copy_idx, state_len).unsqueeze(1).expand(-1, dim, -1)
+        conv_state.scatter_(2, copy_idx, x)
+    out = F.conv1d(x_new, weight.unsqueeze(1), bias, padding=0, groups=dim)[:, :, -seqlen:]
+    if unsqueeze:
+        out = out.squeeze(-1)
+    return (out if activation is None else F.silu(out)).to(dtype=dtype_in)

torch-ext/causal_conv1d/causal_conv1d_varlen.py

@@ -0,0 +1,86 @@
+import torch
+from torch import Tensor
+
+import triton
+import triton.language as tl
+
+
+@triton.jit
+def _causal_conv1d_varlen_states(
+    X,
+    CU_SEQLENS,
+    STATES,
+    state_len,
+    dim,
+    stride_x_seqlen, stride_x_dim,
+    stride_states_batch, stride_states_seqlen, stride_states_dim,
+    BLOCK_M: tl.constexpr,
+    BLOCK_N: tl.constexpr
+):
+    batch_idx = tl.program_id(2)
+    STATES += batch_idx * stride_states_batch
+    end_idx = tl.load(CU_SEQLENS + batch_idx + 1)
+    start_idx = tl.maximum(tl.load(CU_SEQLENS + batch_idx), end_idx - state_len)
+    rows = end_idx - (tl.program_id(1) + 1) * BLOCK_M + tl.arange(0, BLOCK_M)
+    cols = tl.program_id(0) * BLOCK_N + tl.arange(0, BLOCK_N)
+    x = tl.load(X + rows[:, None] * stride_x_seqlen + cols[None, :] * stride_x_dim,
+                mask=(rows[:, None] >= start_idx) & (cols[None, :] < dim),
+                other=0)
+    rows_states = state_len - (tl.program_id(1) + 1) * BLOCK_M + tl.arange(0, BLOCK_M)
+    tl.store(STATES + rows_states[:, None] * stride_states_seqlen + cols[None, :] * stride_states_dim,
+             x,
+             mask=(rows_states[:, None] >= 0) & (cols[None, :] < dim))
+
+
+def causal_conv1d_varlen_states(x: Tensor, cu_seqlens: Tensor, state_len: int) -> Tensor:
+    """
+    Forward pass only, does not support backward pass.
+    Parameters:
+        x: (total_tokens, dim)
+        cu_seqlens: (batch + 1), must already be sorted. The cumulative sum of the sequence lengths, starting from 0.
+        state_len: int. For each cu_seqlens, how many elements from x should be copied to the state.
+            If some of those elements belong to a different sequence, the value of the states will be zero.
+    Return:
+        states: (batch, dim, state_len)
+    """
+    _, dim = x.shape
+    batch = cu_seqlens.shape[0] - 1
+    cu_seqlens = cu_seqlens.contiguous()
+    states = torch.empty(batch, state_len, dim, dtype=x.dtype, device=x.device).transpose(1, 2)
+    BLOCK_M = min(triton.next_power_of_2(state_len), 16)
+    BLOCK_N = min(triton.next_power_of_2(dim), 256)
+    grid = (triton.cdiv(dim, BLOCK_N), triton.cdiv(state_len, BLOCK_M), batch)
+    with torch.cuda.device(x.device.index):
+        _causal_conv1d_varlen_states[grid](
+            x,
+            cu_seqlens,
+            states,
+            state_len,
+            dim,
+            x.stride(0), x.stride(1),
+            states.stride(0), states.stride(2), states.stride(1),
+            BLOCK_M=BLOCK_M, BLOCK_N=BLOCK_N
+        )
+    return states
+
+
+def causal_conv1d_varlen_states_ref(x: Tensor, cu_seqlens: Tensor, state_len: int) -> Tensor:
+    """
+    Forward pass only, does not support backward pass.
+    Parameters:
+        x: (total_tokens, dim)
+        cu_seqlens: (batch + 1), must already be sorted. The cumulative sum of the sequence lengths, starting from 0.
+        state_len: int. For each cu_seqlens, how many elements from x should be copied to the state.
+            If some of those elements belong to a different sequence, the value of the states will be zero.
+    Return:
+        states: (batch, dim, state_len)
+    """
+    _, dim = x.shape
+    batch = cu_seqlens.shape[0] - 1
+    cu_seqlens = cu_seqlens.contiguous()
+    states = torch.zeros(batch, state_len, dim, dtype=x.dtype, device=x.device).transpose(1, 2)
+    for i in range(batch):
+        end_idx = cu_seqlens[i + 1]
+        start_idx = torch.maximum(cu_seqlens[i], end_idx - state_len)
+        states[i, :, -(end_idx - start_idx):] = x[start_idx:end_idx].T
+    return states

torch-ext/causal_conv1d/cpp_functions.py

@@ -0,0 +1,96 @@
+# Copyright (c) 2024, Tri Dao.
+
+import torch
+
+from ._ops import ops
+
+def causal_conv1d_fwd_function(
+    x: torch.Tensor,
+    weight: torch.Tensor,
+    bias: torch.Tensor | None,
+    seq_idx: torch.Tensor | None,
+    initial_states: torch.Tensor | None,
+    final_states_out: torch.Tensor | None,
+    silu_activation: bool,
+) -> torch.Tensor:
+    out = torch.empty_like(x)
+    ops.causal_conv1d_fwd(
+        x=x,
+        weight=weight,
+        bias=bias,
+        seq_idx=seq_idx,
+        initial_states=initial_states,
+        out=out,
+        final_states_out=final_states_out,
+        silu_activation=silu_activation,
+    )
+    return out
+
+
+def causal_conv1d_bwd_function(
+    x: torch.Tensor,
+    weight: torch.Tensor,
+    bias: torch.Tensor | None,
+    dout: torch.Tensor,
+    seq_idx: torch.Tensor | None,
+    initial_states: torch.Tensor | None,
+    dfinal_states: torch.Tensor | None,
+    dx: torch.Tensor | None,
+    return_dinitial_states: torch.Tensor,
+    silu_activation: bool,
+) -> tuple[torch.Tensor | None]:
+    batch_size, dim = x.size()[:2]
+    width = weight.size(-1)
+
+    if dx is None:
+        dx = torch.empty_like(x)
+    dweight = torch.zeros_like(weight, dtype=torch.float32)
+    dbias = None
+    if bias is not None:
+        dbias = torch.zeros_like(bias, dtype=torch.float32)
+    dinitial_states = None
+    if return_dinitial_states:
+        dinitial_states = torch.empty(batch_size, width - 1, dim, device=x.device, dtype=x.dtype).transpose(1, 2)
+
+    ops.causal_conv1d_bwd(
+        x=x,
+        weight=weight,
+        bias=bias,
+        dout=dout,
+        seq_idx=seq_idx,
+        initial_states=initial_states,
+        dfinal_states=dfinal_states,
+        dx=dx,
+        dweight=dweight,
+        dbias=dbias,
+        dinitial_states=dinitial_states,
+        silu_activation=silu_activation,
+    )
+
+    dweight = dweight.type_as(weight)
+    if dbias is not None:
+        dbias = dbias.type_as(bias)
+    return dx, dweight, dbias, dinitial_states
+
+
+def causal_conv1d_update_function(
+    x: torch.Tensor,
+    conv_state: torch.Tensor,
+    weight: torch.Tensor,
+    bias: torch.Tensor | None,
+    silu_activation: bool,
+    cache_seqlens: torch.Tensor | None,
+    conv_state_indices: torch.Tensor | None,
+) -> torch.Tensor:
+    out = torch.empty_like(x)
+    ops.causal_conv1d_update(
+        x=x,
+        conv_state=conv_state,
+        weight=weight,
+        bias=bias,
+        out=out,
+        silu_activation=silu_activation,
+        cache_seqlens=cache_seqlens,
+        conv_state_indices=conv_state_indices,
+    )
+    return out

torch-ext/pytorch_shim.h

@@ -0,0 +1,105 @@
+#pragma once
+
+#include <torch/library.h>
+
+/**
+ * Unforunately, the type signatures of the flash_attn ops are not compatible 
+ * with the PyTorch library bindings. To get around that we use 
+ * `make_pytorch_shim` which creates a lambda that exponses the API using 
+ * PyTorch compatible types to the types, then converts them to the types 
+ * expected by the flash_attn ops. This shims allows us to make minimal changes
+ * to `flash_api.cpp` making it easier to synchronize with upstream changes.
+ * 
+ * The `pytorch_library_compatible_type` struct is used to map from the 
+ * flash_attn ops types to a PyTorch library compatible one. The main issues is
+ * that the following types are not support by PyTorch libary bindings:
+ *  - `int`
+ *  - `float`
+ *  - `std::optional<T> &`
+ *  - `std::optional<const at::Tensor> &`
+ * So we convert them to (respectively):
+ *  - `int64_t`
+ *  - `double`
+ *  - `const std::optional<T>&`
+ *  - `const std::optional<at::Tensor>&`
+ */
+
+template<typename T>
+struct pytorch_library_compatible_type { 
+    using type = T;
+    static T convert_from_type(T arg) { return arg; }
+};
+
+template<typename T>
+using pytorch_library_compatible_type_t = \
+    typename pytorch_library_compatible_type<T>::type;
+
+template<typename T>
+T convert_from_pytorch_compatible_type(pytorch_library_compatible_type_t<T> arg) 
+    { return pytorch_library_compatible_type<T>::convert_from_type(arg); }
+
+// Map `std::optional<T> &` -> `const std::optional<T>&`
+//  (NOTE: this is bit unsafe but non of the ops in flash_attn mutate 
+//   the optional container)
+template<typename T>
+struct pytorch_library_compatible_type<std::optional<T> &> { 
+    using type = const std::optional<T>&;
+    static std::optional<T>& convert_from_type(const std::optional<T> &arg) { 
+        return const_cast<std::optional<T>&>(arg); 
+    }
+};
+
+// Map `std::optional<T>` -> 
+//          `std::optional<pytorch_library_compatible_type_t<T>>`
+//  (NOTE: tested for `std::optional<int>` -> `std::optional<int64_t>`)
+template<typename T>
+struct pytorch_library_compatible_type<std::optional<T>> { 
+    using type = std::optional<pytorch_library_compatible_type_t<T>>;
+    static std::optional<pytorch_library_compatible_type_t<T>> convert_from_type(std::optional<T> arg) { 
+        return arg; 
+    }
+};
+
+// Map `std::optional<const at::Tensor>&` -> `const std::optional<at::Tensor>&`
+template<>
+struct pytorch_library_compatible_type<std::optional<const at::Tensor> &> { 
+    using type = const std::optional<at::Tensor>&;
+    static std::optional<const at::Tensor>& convert_from_type(
+        const std::optional<at::Tensor> &arg) {
+        return const_cast<std::optional<const at::Tensor>&>(
+            reinterpret_cast<const std::optional<const at::Tensor>&>(arg)); 
+    }
+};
+
+// Map `int` -> `int64_t`
+template<> struct pytorch_library_compatible_type<int> { 
+    using type = int64_t; 
+    static int convert_from_type(int64_t arg) {
+        TORCH_CHECK(arg <= std::numeric_limits<int>::max(), 
+            "int64_t value is too large to be converted to int");
+        TORCH_CHECK(arg >= std::numeric_limits<int>::min(), 
+            "int64_t value is too small to be converted to int");
+        return arg; 
+    }
+};
+
+// Map `float` -> `double`
+template<> struct pytorch_library_compatible_type<float> { 
+    using type = double; 
+    static float convert_from_type(double arg) { 
+        TORCH_CHECK(std::abs(arg) <= std::numeric_limits<float>::max(), 
+            "double value is too large to be converted to float");
+        return arg; 
+    }
+};
+
+//
+//  Shim Utils
+//
+
+template <typename Ret, typename... Args>
+auto make_pytorch_shim(Ret(*fun)(Args... args)){
+    return [fun](pytorch_library_compatible_type_t<Args>... args) {
+        return fun(convert_from_pytorch_compatible_type<Args>(args)...);
+    };
+}

torch-ext/torch_binding.cpp

@@ -0,0 +1,32 @@
+#include <torch/library.h>
+
+#include "registration.h"
+
+#include "pytorch_shim.h"
+#include "torch_binding.h"
+
+TORCH_LIBRARY_EXPAND(TORCH_EXTENSION_NAME, ops) {
+    ops.def(
+        "causal_conv1d_fwd("
+        "    Tensor x, Tensor weight, Tensor? bias, Tensor? seq_idx,"
+        "    Tensor? initial_states, Tensor! out, Tensor!? final_states_out,"
+        "    bool silu_activation) -> ()");
+    ops.impl("causal_conv1d_fwd", torch::kCUDA, make_pytorch_shim(&causal_conv1d_fwd));
+    
+    ops.def(
+        "causal_conv1d_bwd("
+        "    Tensor x, Tensor weight, Tensor? bias, Tensor! dout,"
+        "    Tensor? seq_idx, Tensor? initial_states, Tensor? dfinal_states,"
+        "    Tensor! dx, Tensor! dweight, Tensor!? dbias,"
+        "    Tensor!? dinitial_states, bool silu_activation) -> ()");
+    ops.impl("causal_conv1d_bwd", torch::kCUDA, make_pytorch_shim(&causal_conv1d_bwd));
+    
+    ops.def(
+        "causal_conv1d_update("
+        "    Tensor x, Tensor conv_state, Tensor weight, Tensor? bias,"
+        "    Tensor! out, bool silu_activation, Tensor? cache_seqlens,"
+        "    Tensor? conv_state_indices) -> ()");
+    ops.impl("causal_conv1d_update", torch::kCUDA, make_pytorch_shim(&causal_conv1d_update));
+}
+
+REGISTER_EXTENSION(TORCH_EXTENSION_NAME)

torch-ext/torch_binding.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <torch/torch.h>
+
+void
+causal_conv1d_fwd(const at::Tensor &x,
+                  const at::Tensor &weight,
+                  const c10::optional<at::Tensor> &bias_,
+                  const c10::optional<at::Tensor> &seq_idx_,
+                  const c10::optional<at::Tensor> &initial_states_,
+                  at::Tensor &out,
+                  c10::optional<at::Tensor> &final_states_out_,
+                  bool silu_activation);
+
+void
+causal_conv1d_bwd(const at::Tensor &x,
+                  const at::Tensor &weight,
+                  const c10::optional<at::Tensor> &bias_,
+                  at::Tensor &dout,
+                  const c10::optional<at::Tensor> &seq_idx_,
+                  const c10::optional<at::Tensor> &initial_states_,
+                  const c10::optional<at::Tensor> &dfinal_states_,
+                  at::Tensor &dx,
+                  at::Tensor &dweight,
+                  c10::optional<at::Tensor> &dbias_,
+                  c10::optional<at::Tensor> &dinitial_states_,
+                  bool silu_activation);
+
+void
+causal_conv1d_update(const at::Tensor &x,
+                     const at::Tensor &conv_state,
+                     const at::Tensor &weight,
+                     const c10::optional<at::Tensor> &bias_,
+                     at::Tensor &out,
+                     bool silu_activation,
+                     const c10::optional<at::Tensor> &cache_seqlens_,
+                     const c10::optional<at::Tensor> &conv_state_indices_
+                     );
+