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| author | Duncan Sands <baldrick@free.fr> | 2011-01-14 00:37:45 +0000 |
|---|---|---|
| committer | Duncan Sands <baldrick@free.fr> | 2011-01-14 00:37:45 +0000 |
| commit | 7f60dc1eb07e712f51b2768700263a32b1f184e3 (patch) | |
| tree | 5c28705aa2e742beff119c358208150c2ff97fa9 /llvm/lib/CodeGen/MachineBasicBlock.cpp | |
| parent | ae6ce377c2370800765a92720ead1c52e10e9cbc (diff) | |
| download | llvm-7f60dc1eb07e712f51b2768700263a32b1f184e3.zip llvm-7f60dc1eb07e712f51b2768700263a32b1f184e3.tar.gz llvm-7f60dc1eb07e712f51b2768700263a32b1f184e3.tar.bz2 | |
Move some shift transforms out of instcombine and into InstructionSimplify.
While there, I noticed that the transform "undef >>a X -> undef" was wrong.
For example if X is 2 then the top two bits must be equal, so the result can
not be anything. I fixed this in the constant folder as well. Also, I made
the transform for "X << undef" stronger: it now folds to undef always, even
though X might be zero. This is in accordance with the LangRef, but I must
admit that it is fairly aggressive. Also, I added "i32 X << 32 -> undef"
following the LangRef and the constant folder, likewise fairly aggressive.
llvm-svn: 123417
Diffstat (limited to 'llvm/lib/CodeGen/MachineBasicBlock.cpp')
0 files changed, 0 insertions, 0 deletions