Using exclusive mode prefetch

CMakeLists.txt

@@ -386,6 +386,11 @@ if(NOT SNMALLOC_HEADER_ONLY_LIBRARY)
       target_compile_definitions(${name} PRIVATE "SNMALLOC_EXPORT=__attribute__((visibility(\"default\")))")
       target_compile_options(${name} PRIVATE
         -fomit-frame-pointer -ffunction-sections)
+
+      check_cxx_compiler_flag("-Werror -Wextra -Wall -mprfchw" SUPPORT_PREFETCH_WRITE)
+      if (SUPPORT_PREFETCH_WRITE)
+        target_compile_options(${name} PRIVATE -mprfchw)
+      endif()
       # Static TLS model is unsupported on Haiku.
       if (NOT CMAKE_SYSTEM_NAME STREQUAL "Haiku")
         target_compile_options(${name} PRIVATE -ftls-model=initial-exec)

src/snmalloc/aal/aal.h

@@ -147,7 +147,7 @@ namespace snmalloc
     static inline void prefetch(void* ptr) noexcept
     {
 #if __has_builtin(__builtin_prefetch) && !defined(SNMALLOC_NO_AAL_BUILTINS)
-      __builtin_prefetch(ptr);
+      __builtin_prefetch(ptr, 1, 3);
 #else
       Arch::prefetch(ptr);
 #endif

src/snmalloc/aal/aal_arm.h

@@ -54,7 +54,7 @@ namespace snmalloc
 #elif __has_builtin(__builtin_prefetch) && !defined(SNMALLOC_NO_AAL_BUILTINS)
       __builtin_prefetch(ptr);
 #elif defined(SNMALLOC_VA_BITS_64)
-      __asm__ volatile("prfm pldl1keep, [%0]" : "=r"(ptr));
+      __asm__ volatile("prfm pstl1keep, [%0]" : "=r"(ptr));
 #else
       __asm__ volatile("pld\t[%0]" : "=r"(ptr));
 #endif

src/snmalloc/aal/aal_x86.h

@@ -78,7 +78,11 @@ namespace snmalloc
      */
     static inline void prefetch(void* ptr)
     {
-      _mm_prefetch(reinterpret_cast<const char*>(ptr), _MM_HINT_T0);
+#if defined(_MSC_VER)
+      _m_prefetchw(ptr);
+#else
+      _mm_prefetch(reinterpret_cast<const char*>(ptr), _MM_HINT_ET0);
+#endif
     }
 
     /**