Add Histogram implementation for c.parallel

c/parallel/include/cccl/c/histogram.h

@@ -0,0 +1,85 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of CUDA Experimental in CUDA Core Compute Libraries,
+// under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+// SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES.
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#ifndef CCCL_C_EXPERIMENTAL
+#  error "C exposure is experimental and subject to change. Define CCCL_C_EXPERIMENTAL to acknowledge this notice."
+#endif // !CCCL_C_EXPERIMENTAL
+
+#include <cuda.h>
+
+#include <cccl/c/extern_c.h>
+#include <cccl/c/types.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+CCCL_C_EXTERN_C_BEGIN
+
+typedef struct cccl_device_histogram_build_result_t
+{
+  int cc;
+  void* cubin;
+  size_t cubin_size;
+  CUlibrary library;
+  cccl_type_info counter_type;
+  int num_active_channels;
+  CUkernel init_kernel;
+  CUkernel sweep_kernel;
+} cccl_device_histogram_build_result_t;
+
+CCCL_C_API CUresult cccl_device_histogram_build(
+  cccl_device_histogram_build_result_t* build,
+  int num_channels,
+  int num_active_channels,
+  cccl_iterator_t d_samples,
+  int num_output_levels_val,
+  cccl_iterator_t d_output_histograms,
+  cccl_value_t d_levels,
+  int64_t num_rows,
+  int64_t row_stride_samples,
+  bool is_evenly_segmented,
+  int cc_major,
+  int cc_minor,
+  const char* cub_path,
+  const char* thrust_path,
+  const char* libcudacxx_path,
+  const char* ctk_path);
+
+CCCL_C_API CUresult cccl_device_histogram_range(
+  cccl_device_histogram_build_result_t build,
+  void* d_temp_storage,
+  size_t* temp_storage_bytes,
+  cccl_iterator_t d_samples,
+  cccl_iterator_t d_output_histograms,
+  cccl_value_t num_output_levels,
+  cccl_value_t d_levels,
+  int64_t num_row_pixels,
+  int64_t num_rows,
+  int64_t row_stride_samples,
+  CUstream stream);
+
+CCCL_C_API CUresult cccl_device_histogram_even(
+  cccl_device_histogram_build_result_t build,
+  void* d_temp_storage,
+  size_t* temp_storage_bytes,
+  cccl_iterator_t d_samples,
+  cccl_iterator_t d_output_histograms,
+  cccl_value_t num_output_levels,
+  cccl_value_t lower_level,
+  cccl_value_t upper_level,
+  int64_t num_row_pixels,
+  int64_t num_rows,
+  int64_t row_stride_samples,
+  CUstream stream);
+
+CCCL_C_API CUresult cccl_device_histogram_cleanup(cccl_device_histogram_build_result_t* bld_ptr);
+
+CCCL_C_EXTERN_C_END