From 29fe20a98b0616be8f45c8cea2f49d096e78526d Mon Sep 17 00:00:00 2001 From: Reid Spencer Date: Fri, 2 Mar 2007 23:31:34 +0000 Subject: Guard against huge loop trip counts in an APInt safe way. llvm-svn: 34858 --- llvm/lib/Transforms/Scalar/LoopUnroll.cpp | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'llvm/lib/Transforms') 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(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 = " -- cgit v1.2.3