From 108e902aebd7d8d09f29dc62fa13c155d2d8b6c2 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 27 Oct 2005 17:13:11 +0000 Subject: [PATCH] Do not sink any instruction with side effects, including vaarg. This fixes PR640 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24046 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/InstructionCombining.cpp | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 7db409d39e2..4aab0963352 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -5717,8 +5717,8 @@ void InstCombiner::removeFromWorkList(Instruction *I) { static bool TryToSinkInstruction(Instruction *I, BasicBlock *DestBlock) { assert(I->hasOneUse() && "Invariants didn't hold!"); - // Cannot move control-flow-involving instructions. - if (isa(I) || isa(I) || isa(I)) return false; + // Cannot move control-flow-involving, volatile loads, vaarg, etc. + if (isa(I) || I->mayWriteToMemory()) return false; // Do not sink alloca instructions out of the entry block. if (isa(I) && I->getParent() == &DestBlock->getParent()->front()) @@ -5727,8 +5727,6 @@ static bool TryToSinkInstruction(Instruction *I, BasicBlock *DestBlock) { // We can only sink load instructions if there is nothing between the load and // the end of block that could change the value. if (LoadInst *LI = dyn_cast(I)) { - if (LI->isVolatile()) return false; // Don't sink volatile loads. - for (BasicBlock::iterator Scan = LI, E = LI->getParent()->end(); Scan != E; ++Scan) if (Scan->mayWriteToMemory()) -- 2.34.1