From 3c947045ef67a30d2a4400c820b3a9ab912ff92c Mon Sep 17 00:00:00 2001 From: Nick Lewycky Date: Tue, 8 Jul 2008 05:05:37 +0000 Subject: Expand SCEVUDiv of power of 2 to a lshr instruction. llvm-svn: 53217 --- llvm/lib/Analysis/ScalarEvolutionExpander.cpp | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'llvm/lib/Analysis') diff --git a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp index 593e27300d3..628129dc5f0 100644 --- a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp +++ b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp @@ -129,6 +129,20 @@ Value *SCEVExpander::visitMulExpr(SCEVMulExpr *S) { return V; } +Value *SCEVExpander::visitUDivExpr(SCEVUDivExpr *S) { + Value *LHS = expand(S->getLHS()); + if (SCEVConstant *SC = dyn_cast(S->getRHS())) { + const APInt &RHS = SC->getValue()->getValue(); + if (RHS.isPowerOf2()) + return InsertBinop(Instruction::LShr, LHS, + ConstantInt::get(S->getType(), RHS.logBase2()), + InsertPt); + } + + Value *RHS = expand(S->getRHS()); + return InsertBinop(Instruction::UDiv, LHS, RHS, InsertPt); +} + Value *SCEVExpander::visitAddRecExpr(SCEVAddRecExpr *S) { const Type *Ty = S->getType(); const Loop *L = S->getLoop(); -- cgit v1.2.3