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| author | David Majnemer <david.majnemer@gmail.com> | 2015-01-03 02:33:25 +0000 |
|---|---|---|
| committer | David Majnemer <david.majnemer@gmail.com> | 2015-01-03 02:33:25 +0000 |
| commit | 8df46c92897a8e1ac7925ab5f26d1b47a393a4d6 (patch) | |
| tree | 13b425fde48e02e794a8e1dd21d210646e444ac2 /llvm/lib/Analysis | |
| parent | 0f53d9a2ee556992aaa822fb21da66ca41539ffb (diff) | |
| download | bcm5719-llvm-8df46c92897a8e1ac7925ab5f26d1b47a393a4d6.tar.gz bcm5719-llvm-8df46c92897a8e1ac7925ab5f26d1b47a393a4d6.zip | |
ValueTracking: Make computeKnownBits for Arguments a little more clear
We would sometimes leave the out-param APInts untouched while going
through computeKnownBits. While I don't know of a way to trigger a bug
involving this in practice, it goes against the overall design of
computeKnownBits.
Found via code inspection.
llvm-svn: 225109
Diffstat (limited to 'llvm/lib/Analysis')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 3a0efa76b2f..6fdf4afebc2 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -831,6 +831,9 @@ void computeKnownBits(Value *V, APInt &KnownZero, APInt &KnownOne, if (Align) KnownZero = APInt::getLowBitsSet(BitWidth, countTrailingZeros(Align)); + else + KnownZero.clearAllBits(); + KnownOne.clearAllBits(); // Don't give up yet... there might be an assumption that provides more // information... |
