[llvm-branch-commits] [libclc] libclc: Add work_group_reduce_* functions (PR #185368)
Matt Arsenault via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Mon Mar 9 00:52:15 PDT 2026
https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/185368
None
>From 9d69d49e05776fd1a2d6ff50ef79e3dd6faa43df Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Sun, 8 Mar 2026 17:35:55 +0100
Subject: [PATCH] libclc: Add work_group_reduce_* functions
---
.../clc/collective/clc_work_group_reduce.h | 20 +++++
.../clc/collective/clc_work_group_reduce.inc | 17 ++++
libclc/clc/lib/generic/CMakeLists.txt | 1 +
.../collective/clc_work_group_reduce.cl | 30 +++++++
.../collective/clc_work_group_reduce.inc | 86 +++++++++++++++++++
libclc/opencl/lib/generic/CMakeLists.txt | 1 +
.../generic/collective/work_group_reduce.cl | 15 ++++
.../generic/collective/work_group_reduce.inc | 23 +++++
8 files changed, 193 insertions(+)
create mode 100644 libclc/clc/include/clc/collective/clc_work_group_reduce.h
create mode 100644 libclc/clc/include/clc/collective/clc_work_group_reduce.inc
create mode 100644 libclc/clc/lib/generic/collective/clc_work_group_reduce.cl
create mode 100644 libclc/clc/lib/generic/collective/clc_work_group_reduce.inc
create mode 100644 libclc/opencl/lib/generic/collective/work_group_reduce.cl
create mode 100644 libclc/opencl/lib/generic/collective/work_group_reduce.inc
diff --git a/libclc/clc/include/clc/collective/clc_work_group_reduce.h b/libclc/clc/include/clc/collective/clc_work_group_reduce.h
new file mode 100644
index 0000000000000..5b78ead50370b
--- /dev/null
+++ b/libclc/clc/include/clc/collective/clc_work_group_reduce.h
@@ -0,0 +1,20 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __CLC_COLLECTIVE_CLC_WORK_GROUP_REDUCE_H__
+#define __CLC_COLLECTIVE_CLC_WORK_GROUP_REDUCE_H__
+
+#include "clc/internal/clc.h"
+
+#define __CLC_BODY <clc/collective/clc_work_group_reduce.inc>
+#include <clc/integer/gentype.inc>
+
+#define __CLC_BODY <clc/collective/clc_work_group_reduce.inc>
+#include <clc/math/gentype.inc>
+
+#endif // __CLC_COLLECTIVE_CLC_WORK_GROUP_REDUCE_H__
diff --git a/libclc/clc/include/clc/collective/clc_work_group_reduce.inc b/libclc/clc/include/clc/collective/clc_work_group_reduce.inc
new file mode 100644
index 0000000000000..a95112ca51831
--- /dev/null
+++ b/libclc/clc/include/clc/collective/clc_work_group_reduce.inc
@@ -0,0 +1,17 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, 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
+//
+//===----------------------------------------------------------------------===//
+
+#if defined(__CLC_SCALAR) && \
+ (defined(__CLC_FPSIZE) || __CLC_GENSIZE == 32 || __CLC_GENSIZE == 64)
+_CLC_OVERLOAD _CLC_DECL _CLC_CONST __CLC_GENTYPE
+__clc_work_group_reduce_add(__CLC_GENTYPE x);
+_CLC_OVERLOAD _CLC_DECL _CLC_CONST __CLC_GENTYPE
+__clc_work_group_reduce_min(__CLC_GENTYPE x);
+_CLC_OVERLOAD _CLC_DECL _CLC_CONST __CLC_GENTYPE
+__clc_work_group_reduce_max(__CLC_GENTYPE x);
+#endif
diff --git a/libclc/clc/lib/generic/CMakeLists.txt b/libclc/clc/lib/generic/CMakeLists.txt
index ac4799c035f73..ce7614726e21e 100644
--- a/libclc/clc/lib/generic/CMakeLists.txt
+++ b/libclc/clc/lib/generic/CMakeLists.txt
@@ -18,6 +18,7 @@ libclc_configure_source_list(CLC_GENERIC_SOURCES
atomic/clc_atomic_store.cl
collective/clc_work_group_any_all.cl
collective/clc_work_group_broadcast.cl
+ collective/clc_work_group_reduce.cl
common/clc_degrees.cl
common/clc_radians.cl
common/clc_sign.cl
diff --git a/libclc/clc/lib/generic/collective/clc_work_group_reduce.cl b/libclc/clc/lib/generic/collective/clc_work_group_reduce.cl
new file mode 100644
index 0000000000000..515b533ab6b9c
--- /dev/null
+++ b/libclc/clc/lib/generic/collective/clc_work_group_reduce.cl
@@ -0,0 +1,30 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clc/atomic/clc_atomic_load.h"
+#include "clc/atomic/clc_atomic_store.h"
+#include "clc/collective/clc_work_group_reduce.h"
+#include "clc/subgroup/clc_sub_group_reduce.h"
+#include "clc/synchronization/clc_work_group_barrier.h"
+#include "clc/workitem/clc_get_num_sub_groups.h"
+#include "clc/workitem/clc_get_sub_group_id.h"
+#include "clc/workitem/clc_get_sub_group_local_id.h"
+
+#pragma OPENCL EXTENSION __cl_clang_function_scope_local_variables : enable
+
+enum clc_work_group_reduce_op {
+ clc_work_group_reduce_add,
+ clc_work_group_reduce_min,
+ clc_work_group_reduce_max
+};
+
+#define __CLC_BODY <clc_work_group_reduce.inc>
+#include <clc/integer/gentype.inc>
+
+#define __CLC_BODY <clc_work_group_reduce.inc>
+#include <clc/math/gentype.inc>
diff --git a/libclc/clc/lib/generic/collective/clc_work_group_reduce.inc b/libclc/clc/lib/generic/collective/clc_work_group_reduce.inc
new file mode 100644
index 0000000000000..bac19485f8428
--- /dev/null
+++ b/libclc/clc/lib/generic/collective/clc_work_group_reduce.inc
@@ -0,0 +1,86 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, 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
+//
+//===----------------------------------------------------------------------===//
+
+#if defined(__CLC_SCALAR) && \
+ (defined(__CLC_FPSIZE) || __CLC_GENSIZE == 32 || __CLC_GENSIZE == 64)
+
+_CLC_OVERLOAD _CLC_CONST static __CLC_GENTYPE
+sub_group_reduce_op(__CLC_GENTYPE x, enum clc_work_group_reduce_op opcode) {
+ switch (opcode) {
+ case clc_work_group_reduce_add:
+ return __clc_sub_group_reduce_add(x);
+ case clc_work_group_reduce_min:
+ return __clc_sub_group_reduce_min(x);
+ case clc_work_group_reduce_max:
+ return __clc_sub_group_reduce_max(x);
+ }
+}
+
+_CLC_OVERLOAD
+static __CLC_GENTYPE atomic_reduce_op(__local __CLC_GENTYPE *ptr,
+ __CLC_GENTYPE x,
+ enum clc_work_group_reduce_op opcode) {
+ switch (opcode) {
+ case clc_work_group_reduce_add:
+ return __scoped_atomic_fetch_add(ptr, x, __ATOMIC_RELAXED,
+ __MEMORY_SCOPE_WRKGRP);
+ case clc_work_group_reduce_min:
+ return __scoped_atomic_fetch_min(ptr, x, __ATOMIC_RELAXED,
+ __MEMORY_SCOPE_WRKGRP);
+ case clc_work_group_reduce_max:
+ return __scoped_atomic_fetch_max(ptr, x, __ATOMIC_RELAXED,
+ __MEMORY_SCOPE_WRKGRP);
+ }
+}
+
+_CLC_OVERLOAD
+static __CLC_GENTYPE
+__clc_work_group_reduce_impl(__CLC_GENTYPE a,
+ enum clc_work_group_reduce_op opcode) {
+ uint n = __clc_get_num_sub_groups();
+ a = sub_group_reduce_op(a, opcode);
+ if (n == 1)
+ return a;
+
+ __local __CLC_GENTYPE scratch;
+ uint l = __clc_get_sub_group_local_id();
+ uint i = __clc_get_sub_group_id();
+
+ if ((i == 0) & (l == 0)) {
+ __scoped_atomic_store_n(&scratch, a, __ATOMIC_RELAXED,
+ __MEMORY_SCOPE_WRKGRP);
+ }
+
+ __clc_work_group_barrier(__MEMORY_SCOPE_WRKGRP, __CLC_MEMORY_LOCAL);
+ if ((i != 0) & (l == 0)) {
+ atomic_reduce_op(&scratch, a, opcode);
+ }
+
+ __clc_work_group_barrier(__MEMORY_SCOPE_WRKGRP, __CLC_MEMORY_LOCAL);
+ __CLC_GENTYPE ret =
+ __scoped_atomic_load_n(&scratch, __ATOMIC_RELAXED, __MEMORY_SCOPE_WRKGRP);
+ __clc_work_group_barrier(__MEMORY_SCOPE_WRKGRP, __CLC_MEMORY_LOCAL);
+ return ret;
+}
+
+_CLC_OVERLOAD
+__CLC_GENTYPE __clc_work_group_reduce_add(__CLC_GENTYPE a) {
+ return __clc_work_group_reduce_impl(a, clc_work_group_reduce_add);
+}
+
+_CLC_OVERLOAD
+__CLC_GENTYPE __clc_work_group_reduce_min(__CLC_GENTYPE a) {
+ return __clc_work_group_reduce_impl(a, clc_work_group_reduce_min);
+}
+
+_CLC_OVERLOAD
+__CLC_GENTYPE __clc_work_group_reduce_max(__CLC_GENTYPE a) {
+ return __clc_work_group_reduce_impl(a, clc_work_group_reduce_max);
+}
+
+#endif
diff --git a/libclc/opencl/lib/generic/CMakeLists.txt b/libclc/opencl/lib/generic/CMakeLists.txt
index d380b8b6becfa..ca95e6d5cfe23 100644
--- a/libclc/opencl/lib/generic/CMakeLists.txt
+++ b/libclc/opencl/lib/generic/CMakeLists.txt
@@ -45,6 +45,7 @@ libclc_configure_source_list(OPENCL_GENERIC_SOURCES
atomic/atomic_work_item_fence.cl
collective/work_group_any_all.cl
collective/work_group_broadcast.cl
+ collective/work_group_reduce.cl
common/degrees.cl
common/mix.cl
common/radians.cl
diff --git a/libclc/opencl/lib/generic/collective/work_group_reduce.cl b/libclc/opencl/lib/generic/collective/work_group_reduce.cl
new file mode 100644
index 0000000000000..219106432cfc6
--- /dev/null
+++ b/libclc/opencl/lib/generic/collective/work_group_reduce.cl
@@ -0,0 +1,15 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clc/collective/clc_work_group_reduce.h"
+
+#define __CLC_BODY <work_group_reduce.inc>
+#include <clc/integer/gentype.inc>
+
+#define __CLC_BODY <work_group_reduce.inc>
+#include <clc/math/gentype.inc>
diff --git a/libclc/opencl/lib/generic/collective/work_group_reduce.inc b/libclc/opencl/lib/generic/collective/work_group_reduce.inc
new file mode 100644
index 0000000000000..8a3993ef68587
--- /dev/null
+++ b/libclc/opencl/lib/generic/collective/work_group_reduce.inc
@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, 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
+//
+//===----------------------------------------------------------------------===//
+
+#if defined(__CLC_SCALAR) && (defined(__CLC_FPSIZE) || __CLC_GENSIZE >= 32)
+
+_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE work_group_reduce_add(__CLC_GENTYPE a) {
+ return __clc_work_group_reduce_add(a);
+}
+
+_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE work_group_reduce_min(__CLC_GENTYPE a) {
+ return __clc_work_group_reduce_min(a);
+}
+
+_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE work_group_reduce_max(__CLC_GENTYPE a) {
+ return __clc_work_group_reduce_max(a);
+}
+
+#endif
More information about the llvm-branch-commits
mailing list