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| author | Chris Lattner <sabre@nondot.org> | 2006-09-13 03:54:54 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2006-09-13 03:54:54 +0000 |
| commit | 3496710f25b930251739acc6e2031c17c11d5a8b (patch) | |
| tree | fd9ba777cc07990cd7e7d0e4815300000d3525ea /llvm/lib/Target | |
| parent | 72b503bcadcd23d336baba37f0b2b3c9b6898304 (diff) | |
| download | bcm5719-llvm-3496710f25b930251739acc6e2031c17c11d5a8b.tar.gz bcm5719-llvm-3496710f25b930251739acc6e2031c17c11d5a8b.zip | |
new note
llvm-svn: 30285
Diffstat (limited to 'llvm/lib/Target')
| -rw-r--r-- | llvm/lib/Target/X86/README.txt | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/README.txt b/llvm/lib/Target/X86/README.txt index 8994569ea9c..5e2ab199ad2 100644 --- a/llvm/lib/Target/X86/README.txt +++ b/llvm/lib/Target/X86/README.txt @@ -45,6 +45,19 @@ http://gcc.gnu.org/ml/gcc-patches/2004-09/msg01136.html Another useful one would be ~0ULL >> X and ~0ULL << X. +One better solution for 1LL << x is: + xorl %eax, %eax + xorl %edx, %edx + testb $32, %cl + sete %al + setne %dl + sall %cl, %eax + sall %cl, %edx + +But that requires good 8-bit subreg support. + + + //===---------------------------------------------------------------------===// Compile this: |
