From 86b115c78b6c50c7fedbeab80128b2dcbc3cfc57 Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Sat, 19 Feb 2011 21:54:28 +0000 Subject: [PATCH] Minor x86 README updates. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126054 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/X86/README.txt | 34 ++++++++++++++-------------------- 1 file changed, 14 insertions(+), 20 deletions(-) diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index a7a477d2d5b..c10e1709f66 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -710,23 +710,17 @@ This: { return !full_add(a, b).second; } Should compile to: + addl %esi, %edi + setae %al + movzbl %al, %eax + ret - - _Z11no_overflowjj: - addl %edi, %esi - setae %al - ret - -FIXME: That code looks wrong; bool return is normally defined as zext. - -on x86-64, not: - -__Z11no_overflowjj: - addl %edi, %esi - cmpl %edi, %esi - setae %al - movzbl %al, %eax - ret +on x86-64, instead of the rather stupid-looking: + addl %esi, %edi + setb %al + xorb $1, %al + movzbl %al, %eax + ret //===---------------------------------------------------------------------===// @@ -994,10 +988,10 @@ _foo: instead of: _foo: - movl $255, %eax - orl 4(%esp), %eax - andl $65535, %eax - ret + movl $65280, %eax + andl 4(%esp), %eax + orl $255, %eax + ret //===---------------------------------------------------------------------===//