From 97de92c08d675e5ee5be2e1ebec64cbff86c17f4 Mon Sep 17 00:00:00 2001 From: Devang Patel Date: Thu, 26 May 2011 21:51:06 +0000 Subject: [PATCH] If llvm.dbg.value and the value instruction it refers to are far apart then iSel may not be able to find corresponding Node for llvm.dbg.value during DAG construction. Make iSel's life easier by removing this distance between llvm.dbg.value and its value instruction. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132151 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/CodeGenPrepare.cpp | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Scalar/CodeGenPrepare.cpp b/lib/Transforms/Scalar/CodeGenPrepare.cpp index 483bfe36552..7ba92ba2565 100644 --- a/lib/Transforms/Scalar/CodeGenPrepare.cpp +++ b/lib/Transforms/Scalar/CodeGenPrepare.cpp @@ -548,7 +548,19 @@ bool CodeGenPrepare::OptimizeCallInst(CallInst *CI) { // From here on out we're working with named functions. if (CI->getCalledFunction() == 0) return false; - + + // llvm.dbg.value is far away from the value then iSel may not be able + // handle it properly. iSel will drop llvm.dbg.value if it can not + // find a node corresponding to the value. + if (DbgValueInst *DVI = dyn_cast(CI)) + if (Instruction *VI = dyn_cast_or_null(DVI->getValue())) + if (DVI->getParent() != VI->getParent() || DT->dominates(DVI, VI)) { + DEBUG(dbgs() << "Moving Debug Value before :\n" << *DVI << ' ' << *VI); + DVI->removeFromParent(); + DVI->insertAfter(VI); + return true; + } + // We'll need TargetData from here on out. const TargetData *TD = TLI ? TLI->getTargetData() : 0; if (!TD) return false;