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| author | Chris Lattner <sabre@nondot.org> | 2007-11-02 17:04:20 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2007-11-02 17:04:20 +0000 |
| commit | 389d430c49eec9cc6a9318b7f64992f382a425c4 (patch) | |
| tree | 4aea4e2f46f6de6a4b6c9483df8148e080e2c5f4 /llvm/lib/Target | |
| parent | bfd60eedd7d4365fa7399c8a37bdd59d34a1e04d (diff) | |
| download | bcm5719-llvm-389d430c49eec9cc6a9318b7f64992f382a425c4.tar.gz bcm5719-llvm-389d430c49eec9cc6a9318b7f64992f382a425c4.zip | |
add a note
llvm-svn: 43642
Diffstat (limited to 'llvm/lib/Target')
| -rw-r--r-- | llvm/lib/Target/X86/README.txt | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/README.txt b/llvm/lib/Target/X86/README.txt index 567d5c4ebbd..9a5ca427e1e 100644 --- a/llvm/lib/Target/X86/README.txt +++ b/llvm/lib/Target/X86/README.txt @@ -651,6 +651,26 @@ _f: etc. +Another is: +int usesbb(unsigned int a, unsigned int b) { + return (a < b ? -1 : 0); +} +to: +_usesbb: + movl 8(%esp), %eax + cmpl %eax, 4(%esp) + sbbl %eax, %eax + ret + +instead of: +_usesbb: + xorl %eax, %eax + movl 8(%esp), %ecx + cmpl %ecx, 4(%esp) + movl $4294967295, %ecx + cmovb %ecx, %eax + ret + //===---------------------------------------------------------------------===// Currently we don't have elimination of redundant stack manipulations. Consider |
