From 77fbf069f6dd5f18d992a8d2e03484070f60ba3d Mon Sep 17 00:00:00 2001 From: Florian Hahn Date: Fri, 11 Oct 2019 11:46:40 +0000 Subject: [SCEV] Add stricter verification option. Currently -verify-scev only fails if there is a constant difference between two BE counts. This misses a lot of cases. This patch adds a -verify-scev-strict options, which fails for any non-zero differences, if used together with -verify-scev. With the stricter checking, some unit tests fail because of mis-matches, especially around IndVarSimplify. If there is no reason I am missing for just checking constant deltas, I am planning on looking into the various failures. Reviewers: efriedma, sanjoy.google, reames, atrick Reviewed By: sanjoy.google Differential Revision: https://reviews.llvm.org/D68592 llvm-svn: 374535 --- llvm/lib/Analysis/ScalarEvolution.cpp | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'llvm/lib/Analysis/ScalarEvolution.cpp') diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index c29fc5dbccf..8d4c7c5a55f 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -158,6 +158,9 @@ MaxBruteForceIterations("scalar-evolution-max-iterations", cl::ReallyHidden, static cl::opt VerifySCEV( "verify-scev", cl::Hidden, cl::desc("Verify ScalarEvolution's backedge taken counts (slow)")); +static cl::opt VerifySCEVStrict( + "verify-scev-strict", cl::Hidden, + cl::desc("Enable stricter verification with -verify-scev is passed")); static cl::opt VerifySCEVMap("verify-scev-maps", cl::Hidden, cl::desc("Verify no dangling value in ScalarEvolution's " @@ -11922,14 +11925,14 @@ void ScalarEvolution::verify() const { SE.getTypeSizeInBits(NewBECount->getType())) CurBECount = SE2.getZeroExtendExpr(CurBECount, NewBECount->getType()); - auto *ConstantDelta = - dyn_cast(SE2.getMinusSCEV(CurBECount, NewBECount)); + const SCEV *Delta = SE2.getMinusSCEV(CurBECount, NewBECount); - if (ConstantDelta && ConstantDelta->getAPInt() != 0) { - dbgs() << "Trip Count Changed!\n"; + // Unless VerifySCEVStrict is set, we only compare constant deltas. + if ((VerifySCEVStrict || isa(Delta)) && !Delta->isZero()) { + dbgs() << "Trip Count for " << *L << " Changed!\n"; dbgs() << "Old: " << *CurBECount << "\n"; dbgs() << "New: " << *NewBECount << "\n"; - dbgs() << "Delta: " << *ConstantDelta << "\n"; + dbgs() << "Delta: " << *Delta << "\n"; std::abort(); } } -- cgit v1.2.3