Index: lib/Transforms/Utils/Local.cpp =================================================================== --- lib/Transforms/Utils/Local.cpp +++ lib/Transforms/Utils/Local.cpp @@ -1070,9 +1070,15 @@ if (LdStHasDebugValue(DIVar, LI)) return true; - - Builder.insertDbgValueIntrinsic(LI->getOperand(0), 0, DIVar, DIExpr, - DDI->getDebugLoc(), LI); + + // We are now tracking the loaded value instead of the address. In the + // future if multi-location support is added to the IR, it might be + // preferable to keep tracking both the loaded value and the original + // address in case the alloca can not be elided. + Instruction *DbgValue = + Builder.insertDbgValueIntrinsic(LI, 0, DIVar, DIExpr, + DDI->getDebugLoc(), (Instruction*) nullptr); + DbgValue->insertAfter(LI); return true; } @@ -1114,9 +1120,14 @@ // This is a call by-value or some other instruction that // takes a pointer to the variable. Insert a *value* // intrinsic that describes the alloca. + SmallVector NewDIExpr; + auto *DIExpr = DDI->getExpression(); + if (DIExpr) + NewDIExpr.append(DIExpr->elements_begin(), DIExpr->elements_end()); + NewDIExpr.push_back(dwarf::DW_OP_deref); DIB.insertDbgValueIntrinsic(AI, 0, DDI->getVariable(), - DDI->getExpression(), DDI->getDebugLoc(), - CI); + DIB.createExpression(NewDIExpr), + DDI->getDebugLoc(), CI); } DDI->eraseFromParent(); } Index: test/Transforms/Util/simplify-dbg-declare-load.ll =================================================================== --- /dev/null +++ test/Transforms/Util/simplify-dbg-declare-load.ll @@ -0,0 +1,52 @@ +; RUN: opt -instcombine -S < %s | FileCheck % +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-pc-linux-gnu" + +%foo = type { i64, i32, i32 } + +; Function Attrs: nounwind readnone +declare void @llvm.dbg.declare(metadata, metadata, metadata) #0 +declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #0 + +; Function Attrs: sspreq +define void @julia_fastshortest_6256() #1 { +top: + %cp = alloca %foo, align 8 + call void @llvm.dbg.declare(metadata %foo* %cp, metadata !1, metadata !16), !dbg !17 + br i1 undef, label %idxend, label %fail + +fail: ; preds = %top + unreachable + +idxend: ; preds = %top +; CHECK-NOT call void @llvm.dbg.value(metadata %foo* %cp, i64 0, metadata !1, metadata !16), !dbg !17 + %0 = load %foo, %foo* %cp, align 8 +; CHECK: call void @llvm.dbg.value(metadata %foo %0, i64 0, metadata !1, metadata !16), !dbg !17 + store %foo %0, %foo* undef, align 8 + ret void +} + +attributes #0 = { nounwind readnone } +attributes #1 = { sspreq } + +!llvm.module.flags = !{!0} +!llvm.dbg.cu = !{} + +!0 = !{i32 1, !"Debug Info Version", i32 3} +!1 = !DILocalVariable(name: "cp", scope: !2, file: !3, line: 106, type: !12) +!2 = distinct !DISubprogram(name: "fastshortest", linkageName: "julia_fastshortest_6256", scope: null, file: !3, type: !4, isLocal: false, isDefinition: true, isOptimized: true, variables: !11) +!3 = !DIFile(filename: "grisu/fastshortest.jl", directory: ".") +!4 = !DISubroutineType(types: !5) +!5 = !{!6, !7} +!6 = !DIBasicType(name: "Float64", size: 64, align: 64, encoding: DW_ATE_unsigned) +!7 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !8, size: 64, align: 64) +!8 = !DICompositeType(tag: DW_TAG_structure_type, name: "jl_value_t", file: !9, line: 71, align: 64, elements: !10) +!9 = !DIFile(filename: "julia.h", directory: "") +!10 = !{!7} +!11 = !{} +!12 = !DICompositeType(tag: DW_TAG_structure_type, name: "Float", size: 128, align: 64, elements: !13, runtimeLang: DW_LANG_Julia) +!13 = !{!14, !15, !15} +!14 = !DIBasicType(name: "UInt64", size: 64, align: 64, encoding: DW_ATE_unsigned) +!15 = !DIBasicType(name: "Int32", size: 32, align: 32, encoding: DW_ATE_unsigned) +!16 = !DIExpression() +!17 = !DILocation(line: 106, scope: !2)