From 15983b80a0ceb224b74d2ee5ef53d3eed37dc03b Mon Sep 17 00:00:00 2001
From: Tim Northover <tnorthover@apple.com>
Date: Thu, 30 May 2013 13:19:42 +0000
Subject: X86: use sub-register sequences for MOV*r0 operations

Instead of having a bunch of separate MOV8r0, MOV16r0, ... pseudo-instructions,
it's better to use a single MOV32r0 (which will expand to "xorl %reg, %reg")
and obtain other sizes with EXTRACT_SUBREG and SUBREG_TO_REG. The encoding is
smaller and partial register updates can sometimes be avoided.

Until recently, this sequence was a barrier to rematerialization though. That
should now be fixed so it's an appropriate time to make the change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182928 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/CodeGen/X86/sibcall.ll | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'test/CodeGen/X86/sibcall.ll')

diff --git a/test/CodeGen/X86/sibcall.ll b/test/CodeGen/X86/sibcall.ll
index ceb79ea927..de98cb4bb6 100644
--- a/test/CodeGen/X86/sibcall.ll
+++ b/test/CodeGen/X86/sibcall.ll
@@ -279,7 +279,7 @@ entry:
 ; 32: jmp {{_?}}bar5
 
 ; 64: t17:
-; 64: xorb %al, %al
+; 64: xorl %eax, %eax
 ; 64: jmp {{_?}}bar5
   tail call void (...)* @bar5() nounwind
   ret void
@@ -295,7 +295,7 @@ entry:
 ; 32: fstp %st(0)
 
 ; 64: t18:
-; 64: xorb %al, %al
+; 64: xorl %eax, %eax
 ; 64: jmp {{_?}}bar6
   %0 = tail call double (...)* @bar6() nounwind
   ret void
-- 
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