[llvm-commits] [llvm] r45404 - in /llvm/trunk: lib/Target/X86/README.txt test/CodeGen/X86/sext-load.ll

[Chris Lattner]

Author: lattner
Date: Sat Dec 29 02:19:39 2007
New Revision: 45404

URL: http://llvm.org/viewvc/llvm-project?rev=45404&view=rev
Log:
this xform is implemented.

Added:
    llvm/trunk/test/CodeGen/X86/sext-load.ll
Modified:
    llvm/trunk/lib/Target/X86/README.txt

Modified: llvm/trunk/lib/Target/X86/README.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/README.txt?rev=45404&r1=45403&r2=45404&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/README.txt (original)
+++ llvm/trunk/lib/Target/X86/README.txt Sat Dec 29 02:19:39 2007
@@ -702,28 +702,6 @@
 
 //===---------------------------------------------------------------------===//
 
-We currently compile sign_extend_inreg into two shifts:
-
-long foo(long X) {
-  return (long)(signed char)X;
-}
-
-becomes:
-
-_foo:
-        movl 4(%esp), %eax
-        shll $24, %eax
-        sarl $24, %eax
-        ret
-
-This could be:
-
-_foo:
-        movsbl  4(%esp),%eax
-        ret
-
-//===---------------------------------------------------------------------===//
-
 Consider the expansion of:
 
 uint %test3(uint %X) {

Added: llvm/trunk/test/CodeGen/X86/sext-load.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/sext-load.ll?rev=45404&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/sext-load.ll (added)
+++ llvm/trunk/test/CodeGen/X86/sext-load.ll Sat Dec 29 02:19:39 2007
@@ -0,0 +1,9 @@
+; RUN: llvm-as < %s | llc -march=x86 | grep movsbl
+
+define i32 @foo(i32 %X) nounwind  {
+entry:
+	%tmp12 = trunc i32 %X to i8		; <i8> [#uses=1]
+	%tmp123 = sext i8 %tmp12 to i32		; <i32> [#uses=1]
+	ret i32 %tmp123
+}
+