From: Chris Lattner <sabre@nondot.org>
Date: Fri, 2 Nov 2007 17:04:20 +0000 (+0000)
Subject: add a note
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=253945899ba32793894b9983bce7cce3cb90b6d6;p=oota-llvm.git

add a note


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43642 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt
index 567d5c4ebbd..9a5ca427e1e 100644
--- a/lib/Target/X86/README.txt
+++ b/lib/Target/X86/README.txt
@@ -651,6 +651,26 @@ _f:
 
 etc.
 
+Another is:
+int usesbb(unsigned int a, unsigned int b) {
+       return (a < b ? -1 : 0);
+}
+to:
+_usesbb:
+	movl	8(%esp), %eax
+	cmpl	%eax, 4(%esp)
+	sbbl	%eax, %eax
+	ret
+
+instead of:
+_usesbb:
+	xorl	%eax, %eax
+	movl	8(%esp), %ecx
+	cmpl	%ecx, 4(%esp)
+	movl	$4294967295, %ecx
+	cmovb	%ecx, %eax
+	ret
+
 //===---------------------------------------------------------------------===//
 
 Currently we don't have elimination of redundant stack manipulations. Consider