Author: Amy Huang Date: 2020-08-19T18:36:13+02:00 New Revision: 9b0e9ed0ac5f9047538106c55c84082f12a1945c
URL: https://github.com/llvm/llvm-project/commit/9b0e9ed0ac5f9047538106c55c84082f12a1945c DIFF: https://github.com/llvm/llvm-project/commit/9b0e9ed0ac5f9047538106c55c84082f12a1945c.diff LOG: [globalopt] Change so that emitting fragments doesn't use the type size of DIVariables When turning on -debug-info-kind=constructor we ran into a "fragment covers entire variable" error during thinlto. The fragment is currently always emitted if there is no type size, but sometimes the variable has a forward declared struct type which doesn't have a size. This changes the code to get the type size from the GlobalVariable instead. Differential Revision: https://reviews.llvm.org/D85572 (cherry picked from commit 54b6cca0f28484395ae43bcda4c9f929bc51cfe3) Added: llvm/test/DebugInfo/Generic/global-sra-struct-fwd-decl.ll Modified: llvm/lib/Transforms/IPO/GlobalOpt.cpp Removed: ################################################################################ diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp index d9fb820f7cb5..9524d9a36204 100644 --- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp +++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp @@ -468,19 +468,16 @@ static bool CanDoGlobalSRA(GlobalVariable *GV) { /// Copy over the debug info for a variable to its SRA replacements. static void transferSRADebugInfo(GlobalVariable *GV, GlobalVariable *NGV, uint64_t FragmentOffsetInBits, - uint64_t FragmentSizeInBits) { + uint64_t FragmentSizeInBits, + uint64_t VarSize) { SmallVector<DIGlobalVariableExpression *, 1> GVs; GV->getDebugInfo(GVs); for (auto *GVE : GVs) { DIVariable *Var = GVE->getVariable(); - Optional<uint64_t> VarSize = Var->getSizeInBits(); - DIExpression *Expr = GVE->getExpression(); // If the FragmentSize is smaller than the variable, // emit a fragment expression. - // If the variable size is unknown a fragment must be - // emitted to be safe. - if (!VarSize || FragmentSizeInBits < *VarSize) { + if (FragmentSizeInBits < VarSize) { if (auto E = DIExpression::createFragmentExpression( Expr, FragmentOffsetInBits, FragmentSizeInBits)) Expr = *E; @@ -505,6 +502,7 @@ static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) { assert(GV->hasLocalLinkage()); Constant *Init = GV->getInitializer(); Type *Ty = Init->getType(); + uint64_t VarSize = DL.getTypeSizeInBits(Ty); std::map<unsigned, GlobalVariable *> NewGlobals; @@ -560,7 +558,7 @@ static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) { // Copy over the debug info for the variable. uint64_t Size = DL.getTypeAllocSizeInBits(NGV->getValueType()); uint64_t FragmentOffsetInBits = Layout.getElementOffsetInBits(ElementIdx); - transferSRADebugInfo(GV, NGV, FragmentOffsetInBits, Size); + transferSRADebugInfo(GV, NGV, FragmentOffsetInBits, Size, VarSize); } else { uint64_t EltSize = DL.getTypeAllocSize(ElTy); Align EltAlign = DL.getABITypeAlign(ElTy); @@ -573,7 +571,7 @@ static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) { if (NewAlign > EltAlign) NGV->setAlignment(NewAlign); transferSRADebugInfo(GV, NGV, FragmentSizeInBits * ElementIdx, - FragmentSizeInBits); + FragmentSizeInBits, VarSize); } } diff --git a/llvm/test/DebugInfo/Generic/global-sra-struct-fwd-decl.ll b/llvm/test/DebugInfo/Generic/global-sra-struct-fwd-decl.ll new file mode 100644 index 000000000000..caef2dd4ef78 --- /dev/null +++ b/llvm/test/DebugInfo/Generic/global-sra-struct-fwd-decl.ll @@ -0,0 +1,63 @@ +; RUN: opt -S -globalopt < %s | FileCheck %s +; Generated at -O2 -g from: +; typedef struct {} a; +; static struct { +; long b; +; a c; +; } d; +; e() { +; long f = d.b + 1; +; d.b = f; +; } +; (IR is modified so that d's struct type is forward declared.) + +; Check that the global variable "d" is not +; emitted as a fragment if its struct type is +; forward declared but d.c has zero length, so +; a fragment shouldn't be emitted. + +source_filename = "t.c" +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +%struct.anon = type { i64, %struct.a } +%struct.a = type {} + +; CHECK: @d.0 = internal unnamed_addr global i64 0, align 8, !dbg ![[GVE:.*]] +@d = internal global %struct.anon zeroinitializer, align 8, !dbg !0 + +; Function Attrs: noinline nounwind uwtable +define dso_local i32 @e() #0 !dbg !18 { +entry: + %0 = load i64, i64* getelementptr inbounds (%struct.anon, %struct.anon* @d, i32 0, i32 0), align 8 + %add = add nsw i64 %0, 1 + call void @llvm.dbg.value(metadata i64 %add, metadata !24, metadata !DIExpression()), !dbg !25 + store i64 %add, i64* getelementptr inbounds (%struct.anon, %struct.anon* @d, i32 0, i32 0), align 8 + ret i32 undef +} + +; Function Attrs: nounwind readnone speculatable willreturn +declare void @llvm.dbg.declare(metadata, metadata, metadata) + +; Function Attrs: nounwind readnone speculatable willreturn +declare void @llvm.dbg.value(metadata, metadata, metadata) + +!llvm.dbg.cu = !{!2} +!llvm.module.flags = !{!14, !15} + +; CHECK: ![[GVE]] = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) +!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) +!1 = distinct !DIGlobalVariable(name: "d", scope: !2, file: !3, line: 6, type: !7, isLocal: true, isDefinition: true) +!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !{}, globals: !{!0}, splitDebugInlining: false, nameTableKind: None) +!3 = !DIFile(filename: "t.c", directory: "/") +!7 = distinct !DICompositeType(tag: DW_TAG_structure_type, file: !3, line: 3, flags: DIFlagFwdDecl) +!10 = !DIBasicType(name: "long int", size: 64, encoding: DW_ATE_signed) +!12 = !DIDerivedType(tag: DW_TAG_typedef, name: "a", file: !3, line: 2, baseType: !13) +!13 = distinct !DICompositeType(tag: DW_TAG_structure_type, file: !3, line: 1, elements: !{}) +!14 = !{i32 7, !"Dwarf Version", i32 4} +!15 = !{i32 2, !"Debug Info Version", i32 3} +!18 = distinct !DISubprogram(name: "e", scope: !3, file: !3, line: 7, type: !19, scopeLine: 7, spFlags: DISPFlagDefinition, unit: !2, retainedNodes: !{}) +!19 = !DISubroutineType(types: !{!21}) +!21 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!24 = !DILocalVariable(name: "f", scope: !18, file: !3, line: 8, type: !10) +!25 = !DILocation(line: 0, scope: !18) _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
