[llvm-commits] [llvm] r85331 - /llvm/trunk/lib/Target/X86/README.txt

[Bill Wendling]

Author: void
Date: Tue Oct 27 17:40:45 2009
New Revision: 85331

URL: http://llvm.org/viewvc/llvm-project?rev=85331&view=rev
Log:
Modify note.

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=85331&r1=85330&r2=85331&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/README.txt (original)
+++ llvm/trunk/lib/Target/X86/README.txt Tue Oct 27 17:40:45 2009
@@ -1969,9 +1969,17 @@
         movsbl  %al, %eax
 
 Better:
+
         movl    %esi, %eax
         orl     $-128, %eax
         andl    $-128, %esi
         testb   %dil, %dil
         cmovns  %esi, %eax
         movsbl  %al,%eax
+
+Best (recognize this as 'b = (b & ~0x80) | (a & 0x80)'):
+
+        andb    $-128, %dil
+        andb    $127, %sil
+        orb     %dil, %sil
+        movsbl  %sil, %eax