From 04e586151e7987089d760662126e247012431e90 Mon Sep 17 00:00:00 2001 From: Nikita Popov Date: Sat, 11 Jan 2020 15:10:50 +0100 Subject: [InstCombine] Fix worklist management when removing guard intrinsic When multiple guard intrinsics are merged into one, currently the result of eraseInstFromFunction() is returned -- however, this should only be done if the current instruction is being removed. In this case we're removing a different instruction and should instead report that the current one has been modified by returning it. For this test case, this reduces the number of instcombine iterations from 5 to 2 (the minimum possible). Differential Revision: https://reviews.llvm.org/D72558 --- llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'llvm/lib/Transforms') diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp index bcbc953ecd6..f463c5fa113 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -4179,18 +4179,18 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) { Value *CurrCond = II->getArgOperand(0); // Remove a guard that it is immediately preceded by an identical guard. - if (CurrCond == NextCond) - return eraseInstFromFunction(*NextInst); - // Otherwise canonicalize guard(a); guard(b) -> guard(a & b). - Instruction *MoveI = II->getNextNonDebugInstruction(); - while (MoveI != NextInst) { - auto *Temp = MoveI; - MoveI = MoveI->getNextNonDebugInstruction(); - Temp->moveBefore(II); + if (CurrCond != NextCond) { + Instruction *MoveI = II->getNextNonDebugInstruction(); + while (MoveI != NextInst) { + auto *Temp = MoveI; + MoveI = MoveI->getNextNonDebugInstruction(); + Temp->moveBefore(II); + } + II->setArgOperand(0, Builder.CreateAnd(CurrCond, NextCond)); } - II->setArgOperand(0, Builder.CreateAnd(CurrCond, NextCond)); - return eraseInstFromFunction(*NextInst); + eraseInstFromFunction(*NextInst); + return II; } break; } -- cgit v1.2.3