From 92f7365740e9a116c59a8d33e636ebf6e4699301 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 12 Sep 2006 19:17:09 +0000 Subject: [PATCH] An sinkable instruction may exist with uses, if those uses are in dead blocks. Handle this. This fixes PR908 and Transforms/LICM/2006-09-12-DeadUserOfSunkInstr.ll git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30275 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LICM.cpp | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp index a24b366e8d9..7ca9be01359 100644 --- a/lib/Transforms/Scalar/LICM.cpp +++ b/lib/Transforms/Scalar/LICM.cpp @@ -447,6 +447,8 @@ void LICM::sink(Instruction &I) { if (!isExitBlockDominatedByBlockInLoop(ExitBlocks[0], I.getParent())) { // Instruction is not used, just delete it. CurAST->deleteValue(&I); + if (!I.use_empty()) // If I has users in unreachable blocks, eliminate. + I.replaceAllUsesWith(UndefValue::get(I.getType())); I.eraseFromParent(); } else { // Move the instruction to the start of the exit block, after any PHI @@ -460,6 +462,8 @@ void LICM::sink(Instruction &I) { } else if (ExitBlocks.size() == 0) { // The instruction is actually dead if there ARE NO exit blocks. CurAST->deleteValue(&I); + if (!I.use_empty()) // If I has users in unreachable blocks, eliminate. + I.replaceAllUsesWith(UndefValue::get(I.getType())); I.eraseFromParent(); } else { // Otherwise, if we have multiple exits, use the PromoteMem2Reg function to -- 2.34.1