[llvm] [reland][libc][bazel] Enable software prefetching for memcpy (PR #113886)

[Guillaume Chatelet via llvm-commits]

https://github.com/gchatelet created https://github.com/llvm/llvm-project/pull/113886

This will affect only Bazel configuration for now.
This is a reland of #108939 which has been reverted because of codegen
issues fixed by https://github.com/llvm/llvm-project/pull/113161.


>From 65e03146f5948f31071984e81c128b000651a338 Mon Sep 17 00:00:00 2001
From: Guillaume Chatelet <gchatelet at google.com>
Date: Fri, 20 Sep 2024 15:16:38 +0200
Subject: [PATCH] [reland][libc][bazel] Enable software prefetching for memcpy

This will affect only Bazel configuration for now.
This is a reland of #108939 which has been reverted because of codegen
issues fixed by https://github.com/llvm/llvm-project/pull/113161.
---
 .../bazel/llvm-project-overlay/libc/libc_configure_options.bzl  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/utils/bazel/llvm-project-overlay/libc/libc_configure_options.bzl b/utils/bazel/llvm-project-overlay/libc/libc_configure_options.bzl
index f65da9e98226b6..96d7fa86e9ddf2 100644
--- a/utils/bazel/llvm-project-overlay/libc/libc_configure_options.bzl
+++ b/utils/bazel/llvm-project-overlay/libc/libc_configure_options.bzl
@@ -24,7 +24,7 @@ LIBC_CONFIGURE_OPTIONS = [
     # Documentation in libc/src/string/memory_utils/...
     # "LIBC_COPT_MEMCPY_USE_EMBEDDED_TINY",
     # "LIBC_COPT_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE",
-    # "LIBC_COPT_MEMCPY_X86_USE_SOFTWARE_PREFETCHING",
+    "LIBC_COPT_MEMCPY_X86_USE_SOFTWARE_PREFETCHING",
     "LIBC_COPT_MEMSET_X86_USE_SOFTWARE_PREFETCHING",
 
     # Documentation in libc/docs/dev/printf_behavior.rst