From c02e5a8668b53ea36935000d964723b275df3a75 Mon Sep 17 00:00:00 2001 From: Nate Begeman Date: Sun, 26 Mar 2006 19:19:27 +0000 Subject: [PATCH] Readme note git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27152 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/X86/README.txt | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index 91bdb538e94..58a864e01cc 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -542,6 +542,13 @@ Currently the load folding imull has a higher complexity than the LEA32 pattern. //===---------------------------------------------------------------------===// +We are currently lowering large (1MB+) memmove/memcpy to rep/stosl and rep/movsl +We should leave these as libcalls for everything over a much lower threshold, +since libc is hand tuned for medium and large mem ops (avoiding RFO for large +stores, TLB preheating, etc) + +//===---------------------------------------------------------------------===// + Lower memcpy / memset to a series of SSE 128 bit move instructions when it's feasible.