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| author | Reid Spencer <rspencer@reidspencer.com> | 2007-03-02 23:31:34 +0000 |
|---|---|---|
| committer | Reid Spencer <rspencer@reidspencer.com> | 2007-03-02 23:31:34 +0000 |
| commit | 4e69f48a0a6ef9b36c8f17d6ad4e3b6998c81078 (patch) | |
| tree | 9b4878aed5dc4d068932f355a03ae0ded4cd9408 /lib/Transforms/Scalar/LoopUnroll.cpp | |
| parent | ae6421935bd3f2e48346fd16a21297ed1a28fd32 (diff) | |
| download | external_llvm-4e69f48a0a6ef9b36c8f17d6ad4e3b6998c81078.zip external_llvm-4e69f48a0a6ef9b36c8f17d6ad4e3b6998c81078.tar.gz external_llvm-4e69f48a0a6ef9b36c8f17d6ad4e3b6998c81078.tar.bz2 | |
Guard against huge loop trip counts in an APInt safe way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34858 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Scalar/LoopUnroll.cpp')
| -rw-r--r-- | lib/Transforms/Scalar/LoopUnroll.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/LoopUnroll.cpp b/lib/Transforms/Scalar/LoopUnroll.cpp index d1770da..b0db806 100644 --- a/lib/Transforms/Scalar/LoopUnroll.cpp +++ b/lib/Transforms/Scalar/LoopUnroll.cpp @@ -190,10 +190,15 @@ bool LoopUnroll::visitLoop(Loop *L) { ConstantInt *TripCountC = dyn_cast_or_null<ConstantInt>(L->getTripCount()); if (!TripCountC) return Changed; // Must have constant trip count! - uint64_t TripCountFull = TripCountC->getZExtValue(); - if (TripCountFull != TripCountC->getZExtValue() || TripCountFull == 0) + // Guard against huge trip counts. This also guards against assertions in + // APInt from the use of getZExtValue, below. + if (TripCountC->getValue().getActiveBits() > 32) return Changed; // More than 2^32 iterations??? + uint64_t TripCountFull = TripCountC->getZExtValue(); + if (TripCountFull == 0) + return Changed; // Zero iteraitons? + unsigned LoopSize = ApproximateLoopSize(L); DOUT << "Loop Unroll: F[" << Header->getParent()->getName() << "] Loop %" << Header->getName() << " Loop Size = " |