[libc-commits] [libc] 57a3373 - [libc][c23] add memset_explicit (#83577)
via libc-commits
libc-commits at lists.llvm.org
Thu Mar 7 11:57:38 PST 2024
Author: Schrodinger ZHU Yifan
Date: 2024-03-07T14:57:35-05:00
New Revision: 57a337378f37fa3813992842714c9b06fae20af2
URL: https://github.com/llvm/llvm-project/commit/57a337378f37fa3813992842714c9b06fae20af2
DIFF: https://github.com/llvm/llvm-project/commit/57a337378f37fa3813992842714c9b06fae20af2.diff
LOG: [libc][c23] add memset_explicit (#83577)
Added:
libc/src/string/memset_explicit.cpp
libc/src/string/memset_explicit.h
libc/test/src/string/memset_explicit_test.cpp
Modified:
libc/config/linux/aarch64/entrypoints.txt
libc/config/linux/x86_64/entrypoints.txt
libc/spec/stdc.td
libc/src/string/CMakeLists.txt
libc/test/src/string/CMakeLists.txt
Removed:
################################################################################
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index 06832a41221dd8..c32773f67cda53 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -51,6 +51,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.string.mempcpy
libc.src.string.memrchr
libc.src.string.memset
+ libc.src.string.memset_explicit
libc.src.string.rindex
libc.src.string.stpcpy
libc.src.string.stpncpy
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index bd2006ddb7e985..1f36f127e3c473 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -51,6 +51,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.string.mempcpy
libc.src.string.memrchr
libc.src.string.memset
+ libc.src.string.memset_explicit
libc.src.string.rindex
libc.src.string.stpcpy
libc.src.string.stpncpy
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index a3a856a4ec8507..e09cce0efd9bcc 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -234,6 +234,11 @@ def StdC : StandardSpec<"stdc"> {
RetValSpec<VoidPtr>,
[ArgSpec<VoidPtr>, ArgSpec<IntType>, ArgSpec<SizeTType>]
>,
+ FunctionSpec<
+ "memset_explicit",
+ RetValSpec<VoidPtr>,
+ [ArgSpec<VoidPtr>, ArgSpec<IntType>, ArgSpec<SizeTType>]
+ >,
FunctionSpec<
"strcpy",
RetValSpec<CharPtr>,
diff --git a/libc/src/string/CMakeLists.txt b/libc/src/string/CMakeLists.txt
index 1c893280e8a3c2..56588ffafb86f0 100644
--- a/libc/src/string/CMakeLists.txt
+++ b/libc/src/string/CMakeLists.txt
@@ -441,6 +441,17 @@ add_entrypoint_object(
.memory_utils.inline_memcpy
)
+add_entrypoint_object(
+ memset_explicit
+ SRCS
+ memset_explicit.cpp
+ HDRS
+ memset_explicit.h
+ DEPENDS
+ .string_utils
+ .memory_utils.inline_memset
+)
+
# Helper to define a function with multiple implementations
# - Computes flags to satisfy required/rejected features and arch,
# - Declares an entry point,
diff --git a/libc/src/string/memset_explicit.cpp b/libc/src/string/memset_explicit.cpp
new file mode 100644
index 00000000000000..a8656d1e791e84
--- /dev/null
+++ b/libc/src/string/memset_explicit.cpp
@@ -0,0 +1,25 @@
+//===-- Implementation of memset_explicit ---------------------------------===//
+//
+// 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 "src/string/memset_explicit.h"
+#include "src/__support/common.h"
+#include "src/string/memory_utils/inline_memset.h"
+
+namespace LIBC_NAMESPACE {
+
+[[gnu::noinline]] LLVM_LIBC_FUNCTION(void *, memset_explicit,
+ (void *dst, int value, size_t count)) {
+ // Use the inline memset function to set the memory.
+ inline_memset(dst, static_cast<uint8_t>(value), count);
+ // avoid dead store elimination
+ // The asm itself should also be sufficient to behave as a compiler barrier.
+ asm("" : : "r"(dst) : "memory");
+ return dst;
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/string/memset_explicit.h b/libc/src/string/memset_explicit.h
new file mode 100644
index 00000000000000..f6c189761a123c
--- /dev/null
+++ b/libc/src/string/memset_explicit.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for memset_explicit ---------------*- C++ -*-===//
+//
+// 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 LLVM_LIBC_SRC_STRING_MEMSET_EXPLICIT_H
+#define LLVM_LIBC_SRC_STRING_MEMSET_EXPLICIT_H
+
+#include <stddef.h> // size_t
+
+namespace LIBC_NAMESPACE {
+
+[[gnu::noinline]] void *memset_explicit(void *ptr, int value, size_t count);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_STRING_MEMSET_EXPLICIT_H
diff --git a/libc/test/src/string/CMakeLists.txt b/libc/test/src/string/CMakeLists.txt
index 6088289532d771..c1caec5fd912c8 100644
--- a/libc/test/src/string/CMakeLists.txt
+++ b/libc/test/src/string/CMakeLists.txt
@@ -418,6 +418,16 @@ add_libc_test(
libc.src.string.strxfrm
)
+add_libc_test(
+ memset_explicit_test
+ SUITE
+ libc-string-tests
+ SRCS
+ memset_explicit_test.cpp
+ DEPENDS
+ libc.src.string.memset_explicit
+)
+
# Tests all implementations that can run on the target CPU.
function(add_libc_multi_impl_test name)
get_property(fq_implementations GLOBAL PROPERTY ${name}_implementations)
diff --git a/libc/test/src/string/memset_explicit_test.cpp b/libc/test/src/string/memset_explicit_test.cpp
new file mode 100644
index 00000000000000..bb5111bd639e3a
--- /dev/null
+++ b/libc/test/src/string/memset_explicit_test.cpp
@@ -0,0 +1,31 @@
+//===-- Unittests for memset_explicit -------------------------------------===//
+//
+// 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 "memory_utils/memory_check_utils.h"
+#include "src/string/memset_explicit.h"
+#include "test/UnitTest/Test.h"
+
+namespace LIBC_NAMESPACE {
+
+// Apply the same tests as memset
+
+static inline void Adaptor(cpp::span<char> p1, uint8_t value, size_t size) {
+ LIBC_NAMESPACE::memset_explicit(p1.begin(), value, size);
+}
+
+TEST(LlvmLibcmemsetExplicitTest, SizeSweep) {
+ static constexpr size_t kMaxSize = 400;
+ Buffer DstBuffer(kMaxSize);
+ for (size_t size = 0; size < kMaxSize; ++size) {
+ const char value = size % 10;
+ auto dst = DstBuffer.span().subspan(0, size);
+ ASSERT_TRUE((CheckMemset<Adaptor>(dst, value, size)));
+ }
+}
+
+} // namespace LIBC_NAMESPACE
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