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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 | 29fe20a98b0616be8f45c8cea2f49d096e78526d (patch) | |
| tree | 4c8758b9c1c5c0beadf8f48367f465f3e648bd02 /llvm/lib/Transforms | |
| parent | deaea25eb9813e8d0acde981758c438825aa6fbc (diff) | |
| download | bcm5719-llvm-29fe20a98b0616be8f45c8cea2f49d096e78526d.tar.gz bcm5719-llvm-29fe20a98b0616be8f45c8cea2f49d096e78526d.zip | |
Guard against huge loop trip counts in an APInt safe way.
llvm-svn: 34858
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/LoopUnroll.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Scalar/LoopUnroll.cpp b/llvm/lib/Transforms/Scalar/LoopUnroll.cpp index d1770da8fce..b0db806a495 100644 --- a/llvm/lib/Transforms/Scalar/LoopUnroll.cpp +++ b/llvm/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 = " |
