Modify note.

llvm-svn: 85331
2009-10-27 22:40:45 +00:00 · 2009-10-27 22:40:45 +00:00 · cd4d148040
parent aa8814a877
commit cd4d148040
1 changed files with 8 additions and 0 deletions
--- a/llvm/lib/Target/X86/README.txt
+++ b/llvm/lib/Target/X86/README.txt
@ -1969,9 +1969,17 @@ LBB1_2:
        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