From 75ebc0ec2019f391648d3bc3bac6f6da11cfbabd Mon Sep 17 00:00:00 2001 From: Andrew Trick Date: Tue, 6 Sep 2011 20:20:38 +0000 Subject: [PATCH] Add -verify-indvars for imperfect SCEV trip count verification after indvars. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139169 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/IndVarSimplify.cpp | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp index b12a76acf85..636fefaf22e 100644 --- a/lib/Transforms/Scalar/IndVarSimplify.cpp +++ b/lib/Transforms/Scalar/IndVarSimplify.cpp @@ -76,6 +76,13 @@ namespace llvm { cl::opt DisableIVRewrite( "disable-iv-rewrite", cl::Hidden, cl::desc("Disable canonical induction variable rewriting")); + + // Trip count verification can be enabled by default under NDEBUG if we + // implement a strong expression equivalence checker in SCEV. Until then, we + // use the verify-indvars flag, which may assert in some cases. + cl::opt VerifyIndvars( + "verify-indvars", cl::Hidden, + cl::desc("Verify the ScalarEvolution result after running indvars")); } // Temporary flag for use with -disable-iv-rewrite to force a canonical IV for @@ -1968,7 +1975,8 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) { // Verify that LFTR, and any other change have not interfered with SCEV's // ability to compute trip count. #ifndef NDEBUG - if (DisableIVRewrite && !isa(BackedgeTakenCount)) { + if (DisableIVRewrite && VerifyIndvars && + !isa(BackedgeTakenCount)) { SE->forgetLoop(L); const SCEV *NewBECount = SE->getBackedgeTakenCount(L); if (SE->getTypeSizeInBits(BackedgeTakenCount->getType()) <