From 1c8c544946a21ee46261dee56ffc1fbea1515209 Mon Sep 17 00:00:00 2001 From: Adrian Prantl Date: Thu, 9 Nov 2017 19:50:20 +0000 Subject: [PATCH] Preserve debug info when DAG-combinging (zext (truncate x)) -> (and x, mask). rdar://problem/27139077 llvm-svn: 317825 --- llvm/include/llvm/CodeGen/SelectionDAG.h | 9 +++- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 6 ++- llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp | 38 +++------------ llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 35 ++++++++++++++ llvm/test/DebugInfo/AArch64/dagcombine-zext.ll | 64 +++++++++++++++++++++++++ 5 files changed, 117 insertions(+), 35 deletions(-) create mode 100644 llvm/test/DebugInfo/AArch64/dagcombine-zext.ll diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h index 3fbf46a..bb806c0 100644 --- a/llvm/include/llvm/CodeGen/SelectionDAG.h +++ b/llvm/include/llvm/CodeGen/SelectionDAG.h @@ -1184,16 +1184,21 @@ public: unsigned R, bool IsIndirect, const DebugLoc &DL, unsigned O); - /// Constant + /// Creates a constant SDDbgValue node. SDDbgValue *getConstantDbgValue(DIVariable *Var, DIExpression *Expr, const Value *C, const DebugLoc &DL, unsigned O); - /// FrameIndex + /// Creates a FrameIndex SDDbgValue node. SDDbgValue *getFrameIndexDbgValue(DIVariable *Var, DIExpression *Expr, unsigned FI, const DebugLoc &DL, unsigned O); + /// Transfer debug values from one node to another, while optionally + /// generating fragment expressions for split-up values. + void transferDbgValues(SDValue From, SDValue To, unsigned OffsetInBits = 0, + unsigned SizeInBits = 0); + /// Remove the specified node from the system. If any of its /// operands then becomes dead, remove them as well. Inform UpdateListener /// for each node deleted. diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 86c4f2c..557cf6d 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -7613,7 +7613,11 @@ SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) { if (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT)) { SDValue Op = DAG.getAnyExtOrTrunc(N0.getOperand(0), SDLoc(N), VT); AddToWorklist(Op.getNode()); - return DAG.getZeroExtendInReg(Op, SDLoc(N), MinVT.getScalarType()); + SDValue And = DAG.getZeroExtendInReg(Op, SDLoc(N), MinVT.getScalarType()); + // We may safely transfer the debug info describing the truncate node over + // to the equivalent and operation. + DAG.transferDbgValues(N0, And); + return And; } } diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp index 0d85bcc..053d562 100644 --- a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp @@ -835,34 +835,6 @@ void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo, Hi = Entry.second; } -/// Transfer debug values by generating fragment expressions for split-up -/// values. -static void transferDbgValues(SelectionDAG &DAG, SDValue From, SDValue To, - unsigned OffsetInBits) { - SDNode *FromNode = From.getNode(); - SDNode *ToNode = To.getNode(); - assert(FromNode != ToNode); - - SmallVector ClonedDVs; - for (SDDbgValue *Dbg : DAG.GetDbgValues(FromNode)) { - if (Dbg->getKind() != SDDbgValue::SDNODE) - break; - - DIVariable *Var = Dbg->getVariable(); - if (auto Fragment = DIExpression::createFragmentExpression( - Dbg->getExpression(), OffsetInBits, To.getValueSizeInBits())) { - SDDbgValue *Clone = DAG.getDbgValue(Var, *Fragment, ToNode, To.getResNo(), - Dbg->isIndirect(), Dbg->getDebugLoc(), - Dbg->getOrder()); - ClonedDVs.push_back(Clone); - } - Dbg->setIsInvalidated(); - } - - for (SDDbgValue *Dbg : ClonedDVs) - DAG.AddDbgValue(Dbg, ToNode, false); -} - void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo, SDValue Hi) { assert(Lo.getValueType() == @@ -875,11 +847,13 @@ void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo, // Transfer debug values. if (DAG.getDataLayout().isBigEndian()) { - transferDbgValues(DAG, Op, Hi, 0); - transferDbgValues(DAG, Op, Lo, Hi.getValueSizeInBits()); + DAG.transferDbgValues(Op, Hi, 0, Hi.getValueSizeInBits()); + DAG.transferDbgValues(Op, Lo, Hi.getValueSizeInBits(), + Lo.getValueSizeInBits()); } else { - transferDbgValues(DAG, Op, Lo, 0); - transferDbgValues(DAG, Op, Hi, Lo.getValueSizeInBits()); + DAG.transferDbgValues(Op, Lo, 0, Lo.getValueSizeInBits()); + DAG.transferDbgValues(Op, Hi, Lo.getValueSizeInBits(), + Hi.getValueSizeInBits()); } // Remember that this is the result of the node. diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 2fb2615..1c4589e 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -7026,6 +7026,41 @@ SDDbgValue *SelectionDAG::getFrameIndexDbgValue(DIVariable *Var, return new (DbgInfo->getAlloc()) SDDbgValue(Var, Expr, FI, DL, O); } +void SelectionDAG::transferDbgValues(SDValue From, SDValue To, + unsigned OffsetInBits, + unsigned SizeInBits) { + SDNode *FromNode = From.getNode(); + SDNode *ToNode = To.getNode(); + assert(FromNode != ToNode); + + SmallVector ClonedDVs; + for (SDDbgValue *Dbg : GetDbgValues(FromNode)) { + if (Dbg->getKind() != SDDbgValue::SDNODE) + break; + + DIVariable *Var = Dbg->getVariable(); + auto *Expr = Dbg->getExpression(); + // If a fragment is requested, update the expression. + if (SizeInBits) { + auto Fragment = DIExpression::createFragmentExpression( + Dbg->getExpression(), OffsetInBits, SizeInBits); + if (Fragment) + Expr = *Fragment; + } + // Clone the SbgValue unless the fragment creation failed. + if (!SizeInBits || (SizeInBits && Expr)) { + SDDbgValue *Clone = + getDbgValue(Var, Expr, ToNode, To.getResNo(), Dbg->isIndirect(), + Dbg->getDebugLoc(), Dbg->getOrder()); + ClonedDVs.push_back(Clone); + } + Dbg->setIsInvalidated(); + } + + for (SDDbgValue *Dbg : ClonedDVs) + AddDbgValue(Dbg, ToNode, false); +} + void SelectionDAG::salvageDebugInfo(SDNode &N) { if (!N.getHasDebugValue()) return; diff --git a/llvm/test/DebugInfo/AArch64/dagcombine-zext.ll b/llvm/test/DebugInfo/AArch64/dagcombine-zext.ll new file mode 100644 index 0000000..7460176 --- /dev/null +++ b/llvm/test/DebugInfo/AArch64/dagcombine-zext.ll @@ -0,0 +1,64 @@ +; RUN: llc -filetype=obj -o - %s | llvm-dwarfdump --name cntrl_flags - | FileCheck %s +; CHECK: DW_OP_reg0 W0 +; +; void use(unsigned char); +; f(unsigned long long cntrl_flags, +; int page_count) +; { +; unsigned char tag; +; tag = (((cntrl_flags) >> 32) & 0xFF); +; use(tag); +; } + +source_filename = "test.i" +target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128" +target triple = "arm64-apple-ios5.0.0" + +; Function Attrs: nounwind ssp uwtable +define i32 @f(i64 %cntrl_flags) local_unnamed_addr #0 !dbg !8 { +entry: + tail call void @llvm.dbg.value(metadata i64 %cntrl_flags, metadata !14, metadata !DIExpression()), !dbg !18 + %shr = lshr i64 %cntrl_flags, 32, !dbg !20 + %conv = trunc i64 %shr to i8, !dbg !21 + tail call void @llvm.dbg.value(metadata i8 %conv, metadata !16, metadata !DIExpression()), !dbg !22 + tail call void @use(i8 zeroext %conv) #3, !dbg !23 + ret i32 undef, !dbg !24 +} + +declare void @use(i8 zeroext) local_unnamed_addr + +; Function Attrs: nounwind readnone speculatable +declare void @llvm.dbg.value(metadata, metadata, metadata) #2 + +attributes #0 = { nounwind ssp uwtable } +attributes #2 = { nounwind readnone speculatable } +attributes #3 = { nobuiltin nounwind } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4, !5, !6} +!llvm.ident = !{!7} + +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0 (trunk 317700) (llvm/trunk 317708)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2) +!1 = !DIFile(filename: "test.i", directory: "/") +!2 = !{} +!3 = !{i32 2, !"Dwarf Version", i32 2} +!4 = !{i32 2, !"Debug Info Version", i32 3} +!5 = !{i32 1, !"wchar_size", i32 4} +!6 = !{i32 7, !"PIC Level", i32 2} +!7 = !{!"clang version 6.0.0 (trunk 317700) (llvm/trunk 317708)"} +!8 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 2, type: !9, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !13) +!9 = !DISubroutineType(types: !10) +!10 = !{!11, !11} +!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) +!12 = !DIBasicType(name: "long long unsigned int", size: 64, encoding: DW_ATE_unsigned) +!13 = !{!14, !16} +!14 = !DILocalVariable(name: "cntrl_flags", arg: 1, scope: !8, file: !1, line: 2, type: !12) +!16 = !DILocalVariable(name: "tag", scope: !8, file: !1, line: 5, type: !17) +!17 = !DIBasicType(name: "unsigned char", size: 8, encoding: DW_ATE_unsigned_char) +!18 = !DILocation(line: 2, column: 22, scope: !8) +!19 = !DILocation(line: 3, column: 31, scope: !8) +!20 = !DILocation(line: 6, column: 24, scope: !8) +!21 = !DILocation(line: 6, column: 8, scope: !8) +!22 = !DILocation(line: 5, column: 16, scope: !8) +!23 = !DILocation(line: 7, column: 2, scope: !8) +!24 = !DILocation(line: 8, column: 1, scope: !8) -- 2.7.4