From: Nate Begeman <natebegeman@mac.com>
Date: Sun, 26 Mar 2006 19:19:27 +0000 (+0000)
Subject: Readme note
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=c02e5a8668b53ea36935000d964723b275df3a75;p=oota-llvm.git

Readme note


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27152 91177308-0d34-0410-b5e6-96231b3b80d8
---

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.