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author | Duncan Sands <baldrick@free.fr> | 2011-01-14 00:37:45 +0000 |
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committer | Duncan Sands <baldrick@free.fr> | 2011-01-14 00:37:45 +0000 |
commit | c43cee3fbb3098f0647e50dd2c13bc55b027a228 (patch) | |
tree | 1e584c101d4d96ef46988fd14f156b4e74b21ec4 /lib/Transforms/Utils/BreakCriticalEdges.cpp | |
parent | 68a659d423b56e3cafcc3751b33e2472bb191048 (diff) |
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123417 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Utils/BreakCriticalEdges.cpp')
0 files changed, 0 insertions, 0 deletions