diff options
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 14 | ||||
| -rw-r--r-- | test/DebugInfo/X86/dbg-value-arg-movement.ll | 104 |
2 files changed, 114 insertions, 4 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index a5b43bc0a8e..042a0c3a473 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -5492,10 +5492,16 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) { return nullptr; } - // The value is not used in this block yet (or it would have an SDNode). - // We still want the value to appear for the user if possible -- if it has - // an associated VReg, we can refer to that instead. - if (!isa<Argument>(V)) { + // Special rules apply for the first dbg.values of parameter variables in a + // function. Identify them by the fact they reference Argument Values, that + // they're parameters, and they are parameters of the current function. We + // need to let them dangle until they get an SDNode. + bool IsParamOfFunc = isa<Argument>(V) && Variable->isParameter() && + !DI.getDebugLoc()->getInlinedAt(); + if (!IsParamOfFunc) { + // The value is not used in this block yet (or it would have an SDNode). + // We still want the value to appear for the user if possible -- if it has + // an associated VReg, we can refer to that instead. auto VMI = FuncInfo.ValueMap.find(V); if (VMI != FuncInfo.ValueMap.end()) { unsigned Reg = VMI->second; diff --git a/test/DebugInfo/X86/dbg-value-arg-movement.ll b/test/DebugInfo/X86/dbg-value-arg-movement.ll new file mode 100644 index 00000000000..b5692b80435 --- /dev/null +++ b/test/DebugInfo/X86/dbg-value-arg-movement.ll @@ -0,0 +1,104 @@ +; RUN: llc -mtriple=x86_64-unknown-unknown -start-after=codegenprepare -stop-before=expand-isel-pseudos %s -o - | FileCheck %s + +; Test the movement of dbg.values of arguments. SelectionDAG tries to be +; helpful and places DBG_VALUEs of Arguments at the start of functions. +; Unfortunately, this doesn't necessarily make sense, as one can specify an +; Argument IR Value as a variable location anywhere in the program. +; +; Distinguish cases where we want to hoist DBG_VALUEs, and those where we +; don't, by whether the referred to variable is a parameter to the current +; function. In the test below, 'xyzzy' is a parameter to an inlined function, +; but should not be hoisted to the start of the function. +; +; Original test case, in which 'xyzzy' became unavailable because its DBG_VALUE +; landed far from any uses, compiled "clang -O2 -g" with inlining, +; +; int ext(void); +; +; int +; foo(int xyzzy) +; { +; xyzzy = ext() * xyzzy; +; xyzzy += 1; +; ext(); +; return xyzzy; +; } +; +; int +; bar(int baz, int qux) +; { +; int fish; +; switch (qux) { +; case 12: fish = 8; break; +; case 848: fish = 0; break; +; case 99999: fish = -1; break; +; default: fish = 12; +; } +; qux %= fish; +; qux += foo(baz); +; return qux; +; } + +; CHECK: [[BAZVAR:![0-9]+]] = !DILocalVariable(name: "baz", +; CHECK: [[XYZVAR:![0-9]+]] = !DILocalVariable(name: "xyzzy", + +; Start of MIR function block, +; CHECK-LABEL: body +; Expect DBG_VALUE of physreg, +; CHECK: DBG_VALUE $edi, $noreg, [[BAZVAR]] +; Expect DBG_VALUE of virtreg, +; CHECK: DBG_VALUE [[ARGREG:%[0-9]+]], $noreg, [[BAZVAR]] +; Label for next block, +; CHECK-LABEL: bb.1.next +; Correctly place dbg.value in the 'next' block. +; CHECK: DBG_VALUE [[ARGREG]], $noreg, [[XYZVAR]] + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +declare i32 @ext() + +define dso_local i32 @bar(i32, i32) local_unnamed_addr !dbg !7 { + %3 = srem i32 %1, %0, !dbg !15 + call void @llvm.dbg.value(metadata i32 %0, metadata !12, metadata !DIExpression()), !dbg !16 + br label %next + +next: ; preds = %2 + call void @llvm.dbg.value(metadata i32 %0, metadata !17, metadata !DIExpression()), !dbg !22 + %4 = tail call i32 @ext(), !dbg !24 + %5 = mul nsw i32 %3, %4, !dbg !25 + %6 = add i32 %5, %0, !dbg !25 + ret i32 %6, !dbg !25 +} + +; Function Attrs: nounwind readnone speculatable +declare void @llvm.dbg.value(metadata, metadata, metadata) + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4, !5} +!llvm.ident = !{!6} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !2, nameTableKind: None) +!1 = !DIFile(filename: "test.c", directory: ".") +!2 = !{} +!3 = !{i32 2, !"Dwarf Version", i32 4} +!4 = !{i32 2, !"Debug Info Version", i32 3} +!5 = !{i32 1, !"wchar_size", i32 4} +!6 = !{!"clang version 8.0.0"} +!7 = distinct !DISubprogram(name: "bar", scope: !1, file: !1, line: 19, type: !8, scopeLine: 20, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !11) +!8 = !DISubroutineType(types: !9) +!9 = !{!10, !10, !10} +!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!11 = !{!12} +!12 = !DILocalVariable(name: "baz", arg: 1, scope: !7, file: !1, line: 19, type: !10) +!15 = !DILocation(line: 35, column: 7, scope: !7) +!16 = !DILocation(line: 19, column: 9, scope: !7) +!17 = !DILocalVariable(name: "xyzzy", arg: 1, scope: !18, file: !1, line: 10, type: !10) +!18 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 10, type: !19, scopeLine: 11, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !21) +!19 = !DISubroutineType(types: !20) +!20 = !{!10, !10} +!21 = !{!17} +!22 = !DILocation(line: 10, column: 9, scope: !18, inlinedAt: !23) +!23 = distinct !DILocation(line: 36, column: 10, scope: !7) +!24 = !DILocation(line: 12, column: 11, scope: !18, inlinedAt: !23) +!25 = !DILocation(line: 37, column: 3, scope: !7) |