diff options
| author | Chris Lattner <sabre@nondot.org> | 2006-05-30 21:29:15 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2006-05-30 21:29:15 +0000 |
| commit | a5d45872962435d7e541666ef10c3e3f4c4b10e9 (patch) | |
| tree | 3f907e6c7608ff90a2560f81fd23ed1fa44cdc9a /llvm | |
| parent | b9342afa56a04fb3a0d3bd79f379b93ede12d485 (diff) | |
| download | bcm5719-llvm-a5d45872962435d7e541666ef10c3e3f4c4b10e9.tar.gz bcm5719-llvm-a5d45872962435d7e541666ef10c3e3f4c4b10e9.zip | |
Add a note
llvm-svn: 28572
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/Target/README.txt | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/llvm/lib/Target/README.txt b/llvm/lib/Target/README.txt index 807768002b5..650eabf2d4d 100644 --- a/llvm/lib/Target/README.txt +++ b/llvm/lib/Target/README.txt @@ -251,3 +251,22 @@ void %test(uint* %P) { ret void } +//===---------------------------------------------------------------------===// + +dag/inst combine "clz(x)>>5 -> x==0" for 32-bit x. + +Compile: + +int bar(int x) +{ + int t = __builtin_clz(x); + return -(t>>5); +} + +to: + +_bar: addic r3,r3,-1 + subfe r3,r3,r3 + blr + + |
