From c8c0fd39931491146efd08d7ac835f2839e41b1e Mon Sep 17 00:00:00 2001 From: Bill Wendling Date: Thu, 1 Sep 2011 21:28:33 +0000 Subject: Change worklist driven deletion to be an iterative process. Duncan noticed this! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138967 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/SCCP.cpp | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) (limited to 'lib/Transforms/Scalar/SCCP.cpp') diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp index 3d52afa2e1..4ac5b2f910 100644 --- a/lib/Transforms/Scalar/SCCP.cpp +++ b/lib/Transforms/Scalar/SCCP.cpp @@ -1688,24 +1688,15 @@ static void DeleteInstructionInBlock(BasicBlock *BB) { // Delete the instructions backwards, as it has a reduced likelihood of // having to update as many def-use and use-def chains. - std::vector WorkList; - WorkList.reserve(BB->size()); - BasicBlock::iterator I = --BasicBlock::iterator(BB->getTerminator()); - - while (true) { - if (!I->use_empty()) - I->replaceAllUsesWith(UndefValue::get(I->getType())); - WorkList.push_back(I); - if (I == BB->begin()) + for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) { + Instruction *Inst = &*I++; + if (isa(Inst)) break; - --I; - } - - for (std::vector::iterator - II = WorkList.begin(), IE = WorkList.end(); II != IE; ++II) { - if (isa(*II)) + if (!Inst->use_empty()) + Inst->replaceAllUsesWith(UndefValue::get(Inst->getType())); + if (isa(Inst)) continue; - BB->getInstList().erase(*II); + BB->getInstList().erase(Inst); ++NumInstRemoved; } } -- cgit v1.2.3