Modify note.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85331 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt
index 5967fd55c09b4d54a00b13c83e70e274c20e73c2..75dde2d28aa1d42a86f2e04e06f46e1034c42896 100644 (file)
--- a/lib/Target/X86/README.txt
+++ b/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