From 30a121b4e83c2bed062cc2d89f4b8fc354ac370e Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Fri, 27 May 2011 18:37:52 +0000 Subject: [PATCH] Don't sink or hoist debug info instrinsics; it isn't useful. This also prevents LICM sinking from erasing debug intrinsics which don't dominate any exit block of the loop. rdar://9143943 . git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132201 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LICM.cpp | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp index d42d4ff837b..eba77d30903 100644 --- a/lib/Transforms/Scalar/LICM.cpp +++ b/lib/Transforms/Scalar/LICM.cpp @@ -372,7 +372,11 @@ bool LICM::canSinkOrHoistInst(Instruction &I) { return !pointerInvalidatedByLoop(LI->getOperand(0), Size, LI->getMetadata(LLVMContext::MD_tbaa)); } else if (CallInst *CI = dyn_cast(&I)) { - // Handle obvious cases efficiently. + // Don't sink or hoist dbg info; it's legal, but not useful. + if (isa(I)) + return false; + + // Handle simple cases by querying alias analysis. AliasAnalysis::ModRefBehavior Behavior = AA->getModRefBehavior(CI); if (Behavior == AliasAnalysis::DoesNotAccessMemory) return true; @@ -445,8 +449,7 @@ void LICM::sink(Instruction &I) { // enough that we handle it as a special (more efficient) case. It is more // efficient to handle because there are no PHI nodes that need to be placed. if (ExitBlocks.size() == 1) { - if (!isa(I) && - !DT->dominates(I.getParent(), ExitBlocks[0])) { + if (!DT->dominates(I.getParent(), ExitBlocks[0])) { // Instruction is not used, just delete it. CurAST->deleteValue(&I); // If I has users in unreachable blocks, eliminate. -- 2.11.0