From 43fc14d6e439d7a1bb7fea059500019d3036e763 Mon Sep 17 00:00:00 2001 From: Dale Johannesen Date: Mon, 26 Mar 2007 03:01:27 +0000 Subject: [PATCH] Look through bitcast when finding IVs. (Chris' patch really.) llvm-svn: 35347 --- lib/Transforms/Scalar/LoopStrengthReduce.cpp | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp index 4ace17f7a4a..f48f828cb6f 100644 --- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -235,6 +235,16 @@ DeleteTriviallyDeadInstructions(std::set &Insts) { /// GetExpressionSCEV - Compute and return the SCEV for the specified /// instruction. SCEVHandle LoopStrengthReduce::GetExpressionSCEV(Instruction *Exp, Loop *L) { + // Pointer to pointer bitcast instructions return the same value as their + // operand. + if (BitCastInst *BCI = dyn_cast(Exp)) { + if (SE->hasSCEV(BCI) || !isa(BCI->getOperand(0))) + return SE->getSCEV(BCI); + SCEVHandle R = GetExpressionSCEV(cast(BCI->getOperand(0)), L); + SE->setSCEV(BCI, R); + return R; + } + // Scalar Evolutions doesn't know how to compute SCEV's for GEP instructions. // If this is a GEP that SE doesn't know about, compute it now and insert it. // If this is not a GEP, or if we have already done this computation, just let