From 4677205010563e5c313f2c9cc0185a9e206cb150 Mon Sep 17 00:00:00 2001 From: Adrian Prantl Date: Sun, 23 Apr 2017 00:44:40 +0000 Subject: [PATCH] Revert "Use DW_OP_stack_value when reconstructing variable values with arithmetic." This reverts commit r301093 while investigating stage2 bot breakage. llvm-svn: 301099 --- llvm/lib/Transforms/Utils/Local.cpp | 45 +++++++---------------- llvm/test/Transforms/InstCombine/debuginfo-dce.ll | 42 ++++----------------- 2 files changed, 20 insertions(+), 67 deletions(-) diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp index 357c303..09924d1 100644 --- a/llvm/lib/Transforms/Utils/Local.cpp +++ b/llvm/lib/Transforms/Utils/Local.cpp @@ -1268,37 +1268,21 @@ static void appendOffset(SmallVectorImpl &Ops, int64_t Offset) { } } -enum { WithStackValue = true }; - -/// Prepend \p DIExpr with a deref and offset operation and optionally turn it -/// into a stack value. +/// Prepend \p DIExpr with a deref and offset operation. static DIExpression *prependDIExpr(DIBuilder &Builder, DIExpression *DIExpr, - bool Deref, int64_t Offset = 0, - bool StackValue = false) { - if (!Deref && !Offset && !StackValue) + bool Deref, int64_t Offset) { + if (!Deref && !Offset) return DIExpr; - - SmallVector Ops; - appendOffset(Ops, Offset); + // Create a copy of the original DIDescriptor for user variable, prepending + // "deref" operation to a list of address elements, as new llvm.dbg.declare + // will take a value storing address of the memory for variable, not + // alloca itself. + SmallVector Ops; if (Deref) Ops.push_back(dwarf::DW_OP_deref); + appendOffset(Ops, Offset); if (DIExpr) - for (auto Op : DIExpr->expr_ops()) { - // A DW_OP_stack_value comes at the end, but before a DW_OP_LLVM_fragment. - if (StackValue) { - if (Op.getOp() == dwarf::DW_OP_stack_value) - StackValue = false; - else if (Op.getOp() == dwarf::DW_OP_LLVM_fragment) { - Ops.push_back(dwarf::DW_OP_stack_value); - StackValue = false; - } - } - Ops.push_back(Op.getOp()); - for (unsigned I = 0; I < Op.getNumArgs(); ++I) - Ops.push_back(Op.getArg(I)); - } - if (StackValue) - Ops.push_back(dwarf::DW_OP_stack_value); + Ops.append(DIExpr->elements_begin(), DIExpr->elements_end()); return Builder.createExpression(Ops); } @@ -1390,15 +1374,12 @@ void llvm::salvageDebugInfo(Instruction &I) { unsigned BitWidth = M.getDataLayout().getPointerSizeInBits(GEP->getPointerAddressSpace()); APInt Offset(BitWidth, 0); - // Rewrite a constant GEP into a DIExpression. Since we are performing - // arithmetic to compute the variable's *value* in the DIExpression, we - // need to mark the expression with a DW_OP_stack_value. + // Rewrite a constant GEP into a DIExpression. if (GEP->accumulateConstantOffset(M.getDataLayout(), Offset)) { auto *DIExpr = DVI->getExpression(); DIBuilder DIB(M, /*AllowUnresolved*/ false); // GEP offsets are i32 and thus always fit into an int64_t. - DIExpr = prependDIExpr(DIB, DIExpr, NoDeref, Offset.getSExtValue(), - WithStackValue); + DIExpr = prependDIExpr(DIB, DIExpr, NoDeref, Offset.getSExtValue()); DVI->setOperand(0, MDWrap(I.getOperand(0))); DVI->setOperand(3, MetadataAsValue::get(I.getContext(), DIExpr)); DEBUG(dbgs() << "SALVAGE: " << *DVI << '\n'); @@ -1410,7 +1391,7 @@ void llvm::salvageDebugInfo(Instruction &I) { // Rewrite the load into DW_OP_deref. auto *DIExpr = DVI->getExpression(); DIBuilder DIB(M, /*AllowUnresolved*/ false); - DIExpr = prependDIExpr(DIB, DIExpr, WithDeref); + DIExpr = prependDIExpr(DIB, DIExpr, WithDeref, 0); DVI->setOperand(0, MDWrap(I.getOperand(0))); DVI->setOperand(3, MetadataAsValue::get(I.getContext(), DIExpr)); DEBUG(dbgs() << "SALVAGE: " << *DVI << '\n'); diff --git a/llvm/test/Transforms/InstCombine/debuginfo-dce.ll b/llvm/test/Transforms/InstCombine/debuginfo-dce.ll index 58e9d7d..e23aef7 100644 --- a/llvm/test/Transforms/InstCombine/debuginfo-dce.ll +++ b/llvm/test/Transforms/InstCombine/debuginfo-dce.ll @@ -23,6 +23,7 @@ target triple = "x86_64-apple-macosx10.12.0" %struct.entry = type { %struct.entry* } +; Function Attrs: nounwind ssp uwtable define void @salvage_load(%struct.entry** %queue) local_unnamed_addr #0 !dbg !14 { entry: %im_not_dead = alloca %struct.entry* @@ -37,6 +38,7 @@ entry: ret void, !dbg !21 } +; Function Attrs: nounwind ssp uwtable define void @salvage_bitcast(%struct.entry* %queue) local_unnamed_addr #0 !dbg !14 { entry: %im_not_dead = alloca i8* @@ -51,54 +53,24 @@ entry: ret void, !dbg !21 } -define void @salvage_gep0(%struct.entry* %queue, %struct.entry* %end) local_unnamed_addr #0 !dbg !14 { +; Function Attrs: nounwind ssp uwtable +define void @salvage_gep(%struct.entry* %queue, %struct.entry* %end) local_unnamed_addr #0 !dbg !14 { entry: %im_not_dead = alloca %struct.entry** %0 = getelementptr inbounds %struct.entry, %struct.entry* %queue, i32 -1, i32 0, !dbg !19 %1 = getelementptr inbounds %struct.entry, %struct.entry* %queue, i32 -1, i32 0, !dbg !19 call void @llvm.dbg.value(metadata %struct.entry** %1, i64 0, metadata !18, metadata !20), !dbg !19 -; CHECK: define void @salvage_gep0 +; CHECK: define void @salvage_gep ; CHECK-NEXT: entry: ; CHECK-NEXT: call void @llvm.dbg.value(metadata %struct.entry* %queue, i64 0, -; CHECK-SAME: metadata ![[GEP0_EXPR:[0-9]+]]) - store %struct.entry** %1, %struct.entry*** %im_not_dead, align 8 - ret void, !dbg !21 -} - -define void @salvage_gep1(%struct.entry* %queue, %struct.entry* %end) local_unnamed_addr #0 !dbg !14 { -entry: - %im_not_dead = alloca %struct.entry** - %0 = getelementptr inbounds %struct.entry, %struct.entry* %queue, i32 -1, i32 0, !dbg !19 - %1 = getelementptr inbounds %struct.entry, %struct.entry* %queue, i32 -1, i32 0, !dbg !19 - call void @llvm.dbg.value(metadata %struct.entry** %1, i64 0, metadata !18, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 32)), !dbg !19 -; CHECK: define void @salvage_gep1 -; CHECK-NEXT: entry: -; CHECK-NEXT: call void @llvm.dbg.value(metadata %struct.entry* %queue, i64 0, -; CHECK-SAME: metadata ![[GEP1_EXPR:[0-9]+]]) - store %struct.entry** %1, %struct.entry*** %im_not_dead, align 8 - ret void, !dbg !21 -} - -define void @salvage_gep2(%struct.entry* %queue, %struct.entry* %end) local_unnamed_addr #0 !dbg !14 { -entry: - %im_not_dead = alloca %struct.entry** - %0 = getelementptr inbounds %struct.entry, %struct.entry* %queue, i32 -1, i32 0, !dbg !19 - %1 = getelementptr inbounds %struct.entry, %struct.entry* %queue, i32 -1, i32 0, !dbg !19 - call void @llvm.dbg.value(metadata %struct.entry** %1, i64 0, metadata !18, metadata !DIExpression(DW_OP_stack_value)), !dbg !19 -; CHECK: define void @salvage_gep2 -; CHECK-NEXT: entry: -; CHECK-NEXT: call void @llvm.dbg.value(metadata %struct.entry* %queue, i64 0, -; CHECK-SAME: metadata ![[GEP2_EXPR:[0-9]+]]) +; CHECK-SAME: metadata ![[GEP_EXPR:[0-9]+]]) store %struct.entry** %1, %struct.entry*** %im_not_dead, align 8 ret void, !dbg !21 } ; CHECK: ![[LOAD_EXPR]] = !DIExpression(DW_OP_deref, DW_OP_plus, 0) ; CHECK: ![[BITCAST_EXPR]] = !DIExpression(DW_OP_plus, 0) -; CHECK: ![[GEP0_EXPR]] = !DIExpression(DW_OP_minus, 8, DW_OP_plus, 0, DW_OP_stack_value) -; CHECK: ![[GEP1_EXPR]] = !DIExpression(DW_OP_minus, 8, DW_OP_stack_value, -; CHECK-SAME: DW_OP_LLVM_fragment, 0, 32) -; CHECK: ![[GEP2_EXPR]] = !DIExpression(DW_OP_minus, 8, DW_OP_stack_value) +; CHECK: ![[GEP_EXPR]] = !DIExpression(DW_OP_minus, 8, DW_OP_plus, 0) ; Function Attrs: nounwind readnone declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1 -- 2.7.4