[libc] Some MSVC compatibility changes for src/string/memory_utils. (#158393)

4 files changed, 27 insertions, 0 deletions

diff --git a/libc/src/string/memory_utils/CMakeLists.txt b/libc/src/string/memory_utils/CMakeLists.txt
index 670db3012957..9cabfb931801 100644
--- a/libc/src/string/memory_utils/CMakeLists.txt
+++ b/libc/src/string/memory_utils/CMakeLists.txt
@@ -42,6 +42,7 @@ add_header_library(
     libc.src.__support.macros.config
     libc.src.__support.macros.optimization
     libc.src.__support.macros.properties.architectures
+    libc.src.__support.macros.properties.compiler
 )
 
 add_header_library(
diff --git a/libc/src/string/memory_utils/op_generic.h b/libc/src/string/memory_utils/op_generic.h
index 37603410e3a5..010f2187a4ff 100644
--- a/libc/src/string/memory_utils/op_generic.h
+++ b/libc/src/string/memory_utils/op_generic.h
@@ -31,6 +31,7 @@
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
 #include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/optimization.h"
+#include "src/__support/macros/properties/compiler.h"
 #include "src/__support/macros/properties/types.h" // LIBC_TYPES_HAS_INT64
 #include "src/string/memory_utils/op_builtin.h"
 #include "src/string/memory_utils/utils.h"
@@ -39,12 +40,22 @@ static_assert((UINTPTR_MAX == 4294967295U) ||
                   (UINTPTR_MAX == 18446744073709551615UL),
               "We currently only support 32- or 64-bit platforms");
 
+#ifdef LIBC_COMPILER_IS_MSVC
+
+namespace LIBC_NAMESPACE_DECL {
+using generic_v128 = __m128i;
+using generic_v256 = __m256i;
+using generic_v512 = __m512i;
+} // namespace LIBC_NAMESPACE_DECL
+
+#else
 namespace LIBC_NAMESPACE_DECL {
 // Compiler types using the vector attributes.
 using generic_v128 = uint8_t __attribute__((__vector_size__(16)));
 using generic_v256 = uint8_t __attribute__((__vector_size__(32)));
 using generic_v512 = uint8_t __attribute__((__vector_size__(64)));
 } // namespace LIBC_NAMESPACE_DECL
+#endif // LIBC_COMPILER_IS_MSVC
 
 namespace LIBC_NAMESPACE_DECL {
 namespace generic {
diff --git a/libc/src/string/memory_utils/op_x86.h b/libc/src/string/memory_utils/op_x86.h
index 8bd84120c4ff..1b4052747552 100644
--- a/libc/src/string/memory_utils/op_x86.h
+++ b/libc/src/string/memory_utils/op_x86.h
@@ -15,6 +15,7 @@
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
 #include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h"
+#include "src/__support/macros/properties/compiler.h"
 
 #if defined(LIBC_TARGET_ARCH_IS_X86)
 
@@ -57,7 +58,12 @@ LIBC_INLINE_VAR constexpr bool K_AVX512_BW = LLVM_LIBC_IS_DEFINED(__AVX512BW__);
 // Memcpy repmovsb implementation
 struct Memcpy {
   LIBC_INLINE static void repmovsb(void *dst, const void *src, size_t count) {
+#ifdef LIBC_COMPILER_IS_MSVC
+    __movsb(static_cast<unsigned char *>(dst),
+            static_cast<const unsigned char *>(src), count);
+#else
     asm volatile("rep movsb" : "+D"(dst), "+S"(src), "+c"(count) : : "memory");
+#endif // LIBC_COMPILER_IS_MSVC
   }
 };
 
@@ -138,8 +144,10 @@ LIBC_INLINE MemcmpReturnType cmp_neq<uint64_t>(CPtr p1, CPtr p2,
 // When we use these SIMD types in template specialization GCC complains:
 // "ignoring attributes on template argument ‘__m128i’ [-Wignored-attributes]"
 // Therefore, we disable this warning in this file.
+#ifndef LIBC_COMPILER_IS_MSVC
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wignored-attributes"
+#endif // !LIBC_COMPILER_IS_MSVC
 
 ///////////////////////////////////////////////////////////////////////////////
 // Specializations for __m128i
@@ -366,7 +374,9 @@ LIBC_INLINE MemcmpReturnType cmp_neq<__m512i>(CPtr p1, CPtr p2, size_t offset) {
 }
 #endif // __AVX512BW__
 
+#ifndef LIBC_COMPILER_IS_MSVC
 #pragma GCC diagnostic pop
+#endif // !LIBC_COMPILER_IS_MSVC
 
 } // namespace generic
 } // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/string/memory_utils/utils.h b/libc/src/string/memory_utils/utils.h
index 0f9c9e36a3dc..86ff4f12e8c2 100644
--- a/libc/src/string/memory_utils/utils.h
+++ b/libc/src/string/memory_utils/utils.h
@@ -17,6 +17,7 @@
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
 #include "src/__support/macros/config.h"     // LIBC_NAMESPACE_DECL
 #include "src/__support/macros/properties/architectures.h"
+#include "src/__support/macros/properties/compiler.h"
 
 #include <stddef.h> // size_t
 
@@ -90,13 +91,17 @@ LIBC_INLINE void memcpy_inline(void *__restrict dst,
   // different value of the Size parameter. This doesn't play well with GCC's
   // Value Range Analysis that wrongly detects out of bounds accesses. We
   // disable these warnings for the purpose of this function.
+#ifndef LIBC_COMPILER_IS_MSVC
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Warray-bounds"
 #pragma GCC diagnostic ignored "-Wstringop-overread"
 #pragma GCC diagnostic ignored "-Wstringop-overflow"
+#endif // !LIBC_COMPILER_IS_MSVC
   for (size_t i = 0; i < Size; ++i)
     static_cast<char *>(dst)[i] = static_cast<const char *>(src)[i];
+#ifndef LIBC_COMPILER_IS_MSVC
 #pragma GCC diagnostic pop
+#endif // !LIBC_COMPILER_IS_MSVC
 #endif
 }