From: Chris Lattner <sabre@nondot.org>
Date: Mon, 8 May 2006 21:24:21 +0000 (+0000)
Subject: add a note
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=8ef67ac3c3d3b21d4d5e9b7275603a6366acef9a;p=oota-llvm.git

add a note


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28176 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt
index b8ec59ae364..af520afe1d8 100644
--- a/lib/Target/X86/README.txt
+++ b/lib/Target/X86/README.txt
@@ -1166,4 +1166,13 @@ pressure.  The scheduling issue is more pronounced without -static.
 The 2) marked instructions are the lowered form of the 1,undef,3,4 
 shufflevector.  It seems that there should be a better way to do it :)
 
+//===---------------------------------------------------------------------===//
+
+If shorter, we should use things like:
+movzwl %ax, %eax
+instead of:
+andl $65535, %EAX
+
+The former can also be used when the two-addressy nature of the 'and' would
+require a copy to be inserted (in X86InstrInfo::convertToThreeAddress).