From af290edea71f20d85338a34377067efeed207e25 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 17 Apr 2007 23:43:50 +0000 Subject: [PATCH] Be more careful when inserting reused instructions. This fixes CodeGen/Generic/2007-04-17-lsr-crash.ll llvm-svn: 36231 --- lib/Analysis/ScalarEvolutionExpander.cpp | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp index a9b88c1155e..c88c7811954 100644 --- a/lib/Analysis/ScalarEvolutionExpander.cpp +++ b/lib/Analysis/ScalarEvolutionExpander.cpp @@ -71,15 +71,20 @@ Value *SCEVExpander::InsertCastOfTo(Instruction::CastOps opcode, Value *V, /// InsertBinop - Insert the specified binary operator, doing a small amount /// of work to avoid inserting an obviously redundant operation. Value *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, Value *LHS, - Value *RHS, Instruction *InsertPt) { + Value *RHS, Instruction *&InsertPt) { // Do a quick scan to see if we have this binop nearby. If so, reuse it. unsigned ScanLimit = 6; for (BasicBlock::iterator IP = InsertPt, E = InsertPt->getParent()->begin(); ScanLimit; --IP, --ScanLimit) { if (BinaryOperator *BinOp = dyn_cast(IP)) if (BinOp->getOpcode() == Opcode && BinOp->getOperand(0) == LHS && - BinOp->getOperand(1) == RHS) + BinOp->getOperand(1) == RHS) { + // If we found the instruction *at* the insert point, insert later + // instructions after it. + if (BinOp == InsertPt) + InsertPt = ++IP; return BinOp; + } if (IP == E) break; }