From: Torok Edwin Date: Sun, 11 Oct 2009 19:15:54 +0000 (+0000) Subject: LICM shouldn't sink/delete debug information. Fix this and add a testcase. X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=commitdiff_plain;h=9289ae85b41eef62ae1fadb93e99d33f723fb682 LICM shouldn't sink/delete debug information. Fix this and add a testcase. For now the metadata of sinked/hoisted instructions is still wrong, but that'll be fixed when instructions will have debug metadata directly attached. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83786 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp index 6df246fa80e..40af0a811d1 100644 --- a/lib/Transforms/Scalar/LICM.cpp +++ b/lib/Transforms/Scalar/LICM.cpp @@ -35,6 +35,7 @@ #include "llvm/Transforms/Scalar.h" #include "llvm/Constants.h" #include "llvm/DerivedTypes.h" +#include "llvm/IntrinsicInst.h" #include "llvm/Instructions.h" #include "llvm/Target/TargetData.h" #include "llvm/Analysis/LoopInfo.h" @@ -140,6 +141,10 @@ namespace { /// void HoistRegion(DomTreeNode *N); + // Cleanup debug information (remove stoppoints with no coressponding + // instructions). + void CleanupDbgInfoRegion(DomTreeNode *N); + /// inSubLoop - Little predicate that returns true if the specified basic /// block is in a subloop of the current one, not the current one itself. /// @@ -287,6 +292,7 @@ bool LICM::runOnLoop(Loop *L, LPPassManager &LPM) { // SinkRegion(DT->getNode(L->getHeader())); HoistRegion(DT->getNode(L->getHeader())); + CleanupDbgInfoRegion(DT->getNode(L->getHeader())); // Now that all loop invariants have been removed from the loop, promote any // memory references to scalars that we can... @@ -338,6 +344,35 @@ void LICM::SinkRegion(DomTreeNode *N) { } } +void LICM::CleanupDbgInfoRegion(DomTreeNode *N) { + BasicBlock *BB = N->getBlock(); + + // If this subregion is not in the top level loop at all, exit. + if (!CurLoop->contains(BB)) return; + + // We are processing blocks in reverse dfo, so process children first... + const std::vector &Children = N->getChildren(); + for (unsigned i = 0, e = Children.size(); i != e; ++i) + CleanupDbgInfoRegion(Children[i]); + + // Only need to process the contents of this block if it is not part of a + // subloop (which would already have been processed). + if (inSubLoop(BB)) return; + + // We modify the basicblock, so don't cache end() + for (BasicBlock::iterator I=BB->begin(); I != BB->end();) { + Instruction *Last = 0; + // Remove consecutive dbgstoppoints, leave only last + do { + if (Last) { + Last->eraseFromParent(); + Changed = true; + } + Last = I; + ++I; + } while (isa(Last) && isa(I)); + } +} /// HoistRegion - Walk the specified region of the CFG (defined by all blocks /// dominated by the specified block, and that are in the current loop) in depth @@ -392,6 +427,10 @@ bool LICM::canSinkOrHoistInst(Instruction &I) { Size = AA->getTypeStoreSize(LI->getType()); return !pointerInvalidatedByLoop(LI->getOperand(0), Size); } else if (CallInst *CI = dyn_cast(&I)) { + if (isa(CI)) { + // Don't hoist/sink dbgstoppoints, we handle them separately + return false; + } // Handle obvious cases efficiently. AliasAnalysis::ModRefBehavior Behavior = AA->getModRefBehavior(CI); if (Behavior == AliasAnalysis::DoesNotAccessMemory) @@ -489,7 +528,6 @@ void LICM::sink(Instruction &I) { // Move the instruction to the start of the exit block, after any PHI // nodes in it. I.removeFromParent(); - BasicBlock::iterator InsertPt = ExitBlocks[0]->getFirstNonPHI(); ExitBlocks[0]->getInstList().insert(InsertPt, &I); } diff --git a/test/Transforms/LICM/licm_preserve_dbginfo.ll b/test/Transforms/LICM/licm_preserve_dbginfo.ll new file mode 100644 index 00000000000..e013c273544 --- /dev/null +++ b/test/Transforms/LICM/licm_preserve_dbginfo.ll @@ -0,0 +1,55 @@ +; RUN: opt -licm -S <%s | FileCheck %s +; Test that licm doesn't sink/delete debug info. +define i32 @foo(i32 %a, i32 %j) nounwind { +entry: +;CHECK: entry: + call void @llvm.dbg.func.start(metadata !0) + call void @llvm.dbg.stoppoint(i32 3, i32 5, metadata !1) +;CHECK: %mul = mul i32 %j, %j + br label %for.cond + +for.cond: +;CHECK: for.cond: + %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ] + %s.0 = phi i32 [ 0, %entry ], [ %add, %for.inc ] + call void @llvm.dbg.stoppoint(i32 4, i32 5, metadata !1) +; CHECK: call void @llvm.dbg.stoppoint(i32 4, i32 5, metadata !1) + %cmp = icmp slt i32 %i.0, %a + br i1 %cmp, label %for.body, label %for.end + +for.body: +;CHECK: for.body: + call void @llvm.dbg.stoppoint(i32 5, i32 2, metadata !1) +;CHECK: call void @llvm.dbg.stoppoint(i32 5, i32 2, metadata !1) + %mul = mul i32 %j, %j + %add = add nsw i32 %s.0, %mul + br label %for.inc + +for.inc: +;CHECK: for.inc: + call void @llvm.dbg.stoppoint(i32 4, i32 18, metadata !1) +;CHECK: call void @llvm.dbg.stoppoint(i32 4, i32 18, metadata !1) + %inc = add nsw i32 %i.0, 1 + br label %for.cond + +for.end: + call void @llvm.dbg.stoppoint(i32 7, i32 5, metadata !1) + br label %0 + +;