diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/X86/README.txt | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index 5967fd55c0..75dde2d28a 100644 --- 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 |