Index: lib/Bitcode/Writer/ValueEnumerator.cpp =================================================================== --- lib/Bitcode/Writer/ValueEnumerator.cpp +++ lib/Bitcode/Writer/ValueEnumerator.cpp @@ -85,6 +85,16 @@ } // end anonymous namespace +/// Look for a value that might be wrapped as metadata, e.g. a value in a +/// metadata operand. Returns nullptr for a non-wrapped input value if +/// OnlyWrapped is true, or it returns the input value as-is if false. +static const Value *skipMetadataWrapper(const Value *V, bool OnlyWrapped) { + if (const auto *MAV = dyn_cast(V)) + if (const auto *VAM = dyn_cast(MAV->getMetadata())) + return VAM->getValue(); + return OnlyWrapped ? nullptr : V; +} + static void orderValue(const Value *V, OrderMap &OM) { if (OM.lookup(V).first) return; @@ -125,6 +135,25 @@ if (!isa(U.get())) orderValue(U.get(), OM); } + + // As constants used in metadata operands are emitted as module-level + // constants, we must order them before other operands. Also, we must order + // these before global values, as these will be read before setting the + // global values' initializers. The latter matters for constants which have + // uses towards other constants that are used as initializers. + for (const Function &F : M) { + if (F.isDeclaration()) + continue; + for (const BasicBlock &BB : F) + for (const Instruction &I : BB) + for (const Value *V : I.operands()) { + if (const Value *Op = skipMetadataWrapper(V, true)) { + if ((isa(*Op) && !isa(*Op)) || + isa(*Op)) + orderValue(Op, OM); + } + } + } OM.LastGlobalConstantID = OM.size(); // Initializers of GlobalValues are processed in @@ -281,9 +310,11 @@ predictValueUseListOrder(&A, &F, OM, Stack); for (const BasicBlock &BB : F) for (const Instruction &I : BB) - for (const Value *Op : I.operands()) + for (const Value *Op : I.operands()) { + Op = skipMetadataWrapper(Op, false); if (isa(*Op) || isa(*Op)) // Visit GlobalValues. predictValueUseListOrder(Op, &F, OM, Stack); + } for (const BasicBlock &BB : F) for (const Instruction &I : BB) predictValueUseListOrder(&I, &F, OM, Stack); Index: lib/IR/AsmWriter.cpp =================================================================== --- lib/IR/AsmWriter.cpp +++ lib/IR/AsmWriter.cpp @@ -118,6 +118,15 @@ } // end anonymous namespace +/// Look for a value that might be wrapped as metadata, e.g. a value in a +/// metadata operand. Returns the input value as-is if it is not wrapped. +static const Value *skipMetadataWrapper(const Value *V) { + if (const auto *MAV = dyn_cast(V)) + if (const auto *VAM = dyn_cast(MAV->getMetadata())) + return VAM->getValue(); + return V; +} + static void orderValue(const Value *V, OrderMap &OM) { if (OM.lookup(V).first) return; @@ -134,8 +143,6 @@ } static OrderMap orderModule(const Module *M) { - // This needs to match the order used by ValueEnumerator::ValueEnumerator() - // and ValueEnumerator::incorporateFunction(). OrderMap OM; for (const GlobalVariable &G : M->globals()) { @@ -169,10 +176,12 @@ for (const BasicBlock &BB : F) { orderValue(&BB, OM); for (const Instruction &I : BB) { - for (const Value *Op : I.operands()) + for (const Value *Op : I.operands()) { + Op = skipMetadataWrapper(Op); if ((isa(*Op) && !isa(*Op)) || isa(*Op)) orderValue(Op, OM); + } orderValue(&I, OM); } } @@ -286,9 +295,11 @@ predictValueUseListOrder(&A, &F, OM, Stack); for (const BasicBlock &BB : F) for (const Instruction &I : BB) - for (const Value *Op : I.operands()) + for (const Value *Op : I.operands()) { + Op = skipMetadataWrapper(Op); if (isa(*Op) || isa(*Op)) // Visit GlobalValues. predictValueUseListOrder(Op, &F, OM, Stack); + } for (const BasicBlock &BB : F) for (const Instruction &I : BB) predictValueUseListOrder(&I, &F, OM, Stack); Index: test/Assembler/metadata-use-uselistorder.ll =================================================================== --- /dev/null +++ test/Assembler/metadata-use-uselistorder.ll @@ -0,0 +1,56 @@ +; RUN: verify-uselistorder %s + +; Reproducer for PR36778. + +; Verify that uses in metadata operands are considered when generating the +; use-list order. + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +@global = local_unnamed_addr global i64 0, align 8 +@global_arr = common local_unnamed_addr global [10 x i64] zeroinitializer, align 16 + +define void @foo() local_unnamed_addr !dbg !6 { +entry: + %0 = load i64, i64* getelementptr inbounds ([10 x i64], [10 x i64]* @global_arr, i64 0, i64 4), align 16 + call void @llvm.dbg.value(metadata i64* getelementptr inbounds ([10 x i64], [10 x i64]* @global_arr, i64 0, i64 5), metadata !10, metadata !DIExpression()), !dbg !13 + %1 = load i64, i64* getelementptr inbounds ([10 x i64], [10 x i64]* @global_arr, i64 0, i64 6), align 16 + call void @llvm.dbg.value(metadata i64* getelementptr inbounds ([10 x i64], [10 x i64]* @global_arr, i64 0, i64 6), metadata !10, metadata !DIExpression()), !dbg !14 + ret void +} + +define void @bar() local_unnamed_addr !dbg !15 { +entry: + call void @llvm.dbg.value(metadata i64* getelementptr inbounds ([10 x i64], [10 x i64]* @global_arr, i64 0, i64 7), metadata !17, metadata !DIExpression()), !dbg !18 + ret void +} + +; Function Attrs: nounwind readnone speculatable +declare void @llvm.dbg.value(metadata, metadata, metadata) #0 + +attributes #0 = { nounwind readnone speculatable } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4} +!llvm.ident = !{!5} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !2, nameTableKind: None) +!1 = !DIFile(filename: "uses.c", directory: "/") +!2 = !{} +!3 = !{i32 2, !"Dwarf Version", i32 4} +!4 = !{i32 2, !"Debug Info Version", i32 3} +!5 = !{!"clang version 8.0.0"} +!6 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 6, type: !7, isLocal: false, isDefinition: true, scopeLine: 6, isOptimized: true, unit: !0, retainedNodes: !9) +!7 = !DISubroutineType(types: !8) +!8 = !{null} +!9 = !{!10} +!10 = !DILocalVariable(name: "local1", scope: !6, file: !1, line: 7, type: !11) +!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64) +!12 = !DIBasicType(name: "long int", size: 64, encoding: DW_ATE_signed) +!13 = !DILocation(line: 8, column: 8, scope: !6) +!14 = !DILocation(line: 7, column: 9, scope: !6) +!15 = distinct !DISubprogram(name: "bar", scope: !1, file: !1, line: 12, type: !7, isLocal: false, isDefinition: true, scopeLine: 12, isOptimized: true, unit: !0, retainedNodes: !16) +!16 = !{!17} +!17 = !DILocalVariable(name: "local2", scope: !15, file: !1, line: 13, type: !11) +!18 = !DILocation(line: 14, column: 1, scope: !15) Index: tools/verify-uselistorder/verify-uselistorder.cpp =================================================================== --- tools/verify-uselistorder/verify-uselistorder.cpp +++ tools/verify-uselistorder/verify-uselistorder.cpp @@ -225,10 +225,16 @@ // Constants used by instructions. for (const BasicBlock &BB : F) for (const Instruction &I : BB) - for (const Value *Op : I.operands()) + for (const Value *Op : I.operands()) { + // Look through a metadata wrapper. + if (const auto *MAV = dyn_cast(Op)) + if (const auto *VAM = dyn_cast(MAV->getMetadata())) + Op = VAM->getValue(); + if ((isa(Op) && !isa(*Op)) || isa(Op)) map(Op); + } } } @@ -501,10 +507,15 @@ // Constants used by instructions. for (BasicBlock &BB : F) for (Instruction &I : BB) - for (Value *Op : I.operands()) + for (Value *Op : I.operands()) { + // Look through a metadata wrapper. + if (auto *MAV = dyn_cast(Op)) + if (auto *VAM = dyn_cast(MAV->getMetadata())) + Op = VAM->getValue(); if ((isa(Op) && !isa(*Op)) || isa(Op)) changeValueUseList(Op); + } } if (verifyModule(M, &errs()))