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| author | Eli Friedman <eli.friedman@gmail.com> | 2011-02-19 21:54:28 +0000 |
|---|---|---|
| committer | Eli Friedman <eli.friedman@gmail.com> | 2011-02-19 21:54:28 +0000 |
| commit | 86b115c78b6c50c7fedbeab80128b2dcbc3cfc57 (patch) | |
| tree | cebce34ef762c0c5b730dc73488384f1fa8456e7 /lib/Target/X86/README.txt | |
| parent | 37d42f8a5072bfd216445b8c1f983686dea0ea1c (diff) | |
| download | external_llvm-86b115c78b6c50c7fedbeab80128b2dcbc3cfc57.zip external_llvm-86b115c78b6c50c7fedbeab80128b2dcbc3cfc57.tar.gz external_llvm-86b115c78b6c50c7fedbeab80128b2dcbc3cfc57.tar.bz2 | |
Minor x86 README updates.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126054 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/README.txt')
| -rw-r--r-- | lib/Target/X86/README.txt | 34 |
1 files changed, 14 insertions, 20 deletions
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index a7a477d..c10e170 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 //===---------------------------------------------------------------------===// |