From bce2ac9f6d3be91fc744f7efe76d52dbe1b683bf Mon Sep 17 00:00:00 2001 From: Pavel Labath Date: Tue, 24 Nov 2020 09:00:42 +0100 Subject: [PATCH] Revert "[DebugInfo] Refactor code for emitting DWARF expressions for FP constants" The commit introduced a crash when emitting (debug info for) complex floats (pr48277). --- llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 21 +++++++-- llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp | 51 ++++++++++------------ llvm/lib/CodeGen/AsmPrinter/DwarfExpression.h | 2 +- llvm/test/DebugInfo/ARM/implicit_value-_Float16.ll | 51 ---------------------- 4 files changed, 41 insertions(+), 84 deletions(-) delete mode 100644 llvm/test/DebugInfo/ARM/implicit_value-_Float16.ll diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp index eb20c9c..5054ed8 100644 --- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp +++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp @@ -2466,11 +2466,24 @@ void DwarfDebug::emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT, // TODO TargetIndexLocation is a target-independent. Currently only the WebAssembly-specific // encoding is supported. DwarfExpr.addWasmLocation(Loc.Index, static_cast(Loc.Offset)); - DwarfExpr.addExpression(std::move(ExprCursor)); - return; + DwarfExpr.addExpression(std::move(ExprCursor)); + return; } else if (Value.isConstantFP()) { - DwarfExpr.addConstantFP(Value.getConstantFP()->getValueAPF(), AP); - return; + if (AP.getDwarfVersion() >= 4 && !AP.getDwarfDebug()->tuneForSCE()) { + DwarfExpr.addConstantFP(Value.getConstantFP()->getValueAPF(), AP); + return; + } else if (Value.getConstantFP() + ->getValueAPF() + .bitcastToAPInt() + .getBitWidth() <= 64 /*bits*/) + DwarfExpr.addUnsignedConstant( + Value.getConstantFP()->getValueAPF().bitcastToAPInt()); + else + LLVM_DEBUG( + dbgs() + << "Skipped DwarfExpression creation for ConstantFP of size" + << Value.getConstantFP()->getValueAPF().bitcastToAPInt().getBitWidth() + << " bits\n"); } DwarfExpr.addExpression(std::move(ExprCursor)); } diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp index 21f7ad1..59ad764 100644 --- a/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp +++ b/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp @@ -200,29 +200,10 @@ void DwarfExpression::addUnsignedConstant(uint64_t Value) { emitConstu(Value); } -void DwarfExpression::addUnsignedConstant(APInt Value, const AsmPrinter &AP) { +void DwarfExpression::addUnsignedConstant(const APInt &Value) { assert(isImplicitLocation() || isUnknownLocation()); LocationKind = Implicit; - if (AP.getDwarfVersion() >= 4 && !AP.getDwarfDebug()->tuneForSCE()) { - int NumBytes = Value.getBitWidth() / 8; - emitOp(dwarf::DW_OP_implicit_value); - emitUnsigned(NumBytes /*Size of the block in bytes*/); - - // The loop below is emitting the value starting at least significant - // byte, so we need to perform a byte-swap to get the byte order correct - // in case of a big-endian target. - if (AP.getDataLayout().isBigEndian()) - Value = Value.byteSwap(); - - for (int i = 0; i < NumBytes; ++i) { - emitData1(Value.getRawData()[0] & 0xFF); - Value = Value.lshr(8); - } - - return; - } - unsigned Size = Value.getBitWidth(); const uint64_t *Data = Value.getRawData(); @@ -231,9 +212,9 @@ void DwarfExpression::addUnsignedConstant(APInt Value, const AsmPrinter &AP) { unsigned Offset = 0; while (Offset < Size) { addUnsignedConstant(*Data++); - addStackValue(); if (Offset == 0 && Size <= 64) break; + addStackValue(); addOpPiece(std::min(Size - Offset, 64u), Offset); Offset += 64; } @@ -243,13 +224,27 @@ void DwarfExpression::addConstantFP(const APFloat &APF, const AsmPrinter &AP) { assert(isImplicitLocation() || isUnknownLocation()); APInt API = APF.bitcastToAPInt(); int NumBytes = API.getBitWidth() / 8; - // FIXME: Add support for `long double`. - if (NumBytes <= 8 /*double*/) - addUnsignedConstant(API, AP); - else - LLVM_DEBUG( - dbgs() << "Skipped DwarfExpression creation for ConstantFP of size" - << API.getBitWidth() << " bits\n"); + if (NumBytes == 4 /*float*/ || NumBytes == 8 /*double*/) { + // FIXME: Add support for `long double`. + emitOp(dwarf::DW_OP_implicit_value); + emitUnsigned(NumBytes /*Size of the block in bytes*/); + + // The loop below is emitting the value starting at least significant byte, + // so we need to perform a byte-swap to get the byte order correct in case + // of a big-endian target. + if (AP.getDataLayout().isBigEndian()) + API = API.byteSwap(); + + for (int i = 0; i < NumBytes; ++i) { + emitData1(API.getZExtValue() & 0xFF); + API = API.lshr(8); + } + + return; + } + LLVM_DEBUG( + dbgs() << "Skipped DW_OP_implicit_value creation for ConstantFP of size: " + << API.getBitWidth() << " bits\n"); } bool DwarfExpression::addMachineRegExpression(const TargetRegisterInfo &TRI, diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.h b/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.h index 796717b..8fca9f5 100644 --- a/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.h +++ b/llvm/lib/CodeGen/AsmPrinter/DwarfExpression.h @@ -297,7 +297,7 @@ public: void addUnsignedConstant(uint64_t Value); /// Emit an unsigned constant. - void addUnsignedConstant(APInt Value, const AsmPrinter &AP); + void addUnsignedConstant(const APInt &Value); /// Emit an floating point constant. void addConstantFP(const APFloat &Value, const AsmPrinter &AP); diff --git a/llvm/test/DebugInfo/ARM/implicit_value-_Float16.ll b/llvm/test/DebugInfo/ARM/implicit_value-_Float16.ll deleted file mode 100644 index 60c9ce4..0000000 --- a/llvm/test/DebugInfo/ARM/implicit_value-_Float16.ll +++ /dev/null @@ -1,51 +0,0 @@ -; RUN: llc -debugger-tune=gdb -filetype=obj %s -o - | llvm-dwarfdump - \ -; RUN: | FileCheck %s --check-prefixes=GDB,BOTH -; RUN: llc -debugger-tune=sce -filetype=obj %s -o - | llvm-dwarfdump - \ -; RUN: | FileCheck %s --check-prefixes=SCE,BOTH - -; BOTH: DW_TAG_variable -; BOTH-NEXT: DW_AT_location -; GDB-NEXT: {{.*}}: DW_OP_implicit_value 0x2 0xe0 0x51 -; SCE-NEXT: {{.*}}: DW_OP_constu 0x51e0, DW_OP_stack_value -; GDB-NEXT: {{.*}}: DW_OP_implicit_value 0x2 0x40 0x51 -; SCE-NEXT: {{.*}}: DW_OP_constu 0x5140, DW_OP_stack_value -; BOTH-NEXT: DW_AT_name ("a") - -source_filename = "-" -target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64" -target triple = "armv7-unknown-unknown" - -define dso_local arm_aapcscc void @f() local_unnamed_addr !dbg !8 { -entry: - call void @llvm.dbg.value(metadata half 0xH51E0, metadata !13, metadata !DIExpression()), !dbg !15 - call arm_aapcscc void bitcast (void (...)* @g to void ()*)(), !dbg !15 - call void @llvm.dbg.value(metadata half 0xH5140, metadata !13, metadata !DIExpression()), !dbg !15 - call arm_aapcscc void bitcast (void (...)* @g to void ()*)(), !dbg !15 - ret void, !dbg !15 -} - -declare dso_local arm_aapcscc void @g(...) local_unnamed_addr - -declare void @llvm.dbg.value(metadata, metadata, metadata) #2 - -attributes #2 = { nofree nosync nounwind readnone speculatable willreturn } - -!llvm.dbg.cu = !{!0} -!llvm.module.flags = !{!3, !4, !5, !6} -!llvm.ident = !{!7} - -!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, emissionKind: FullDebug, enums: !2) -!1 = !DIFile(filename: "-", directory: "/") -!2 = !{} -!3 = !{i32 7, !"Dwarf Version", i32 4} -!4 = !{i32 2, !"Debug Info Version", i32 3} -!5 = !{i32 1, !"wchar_size", i32 4} -!6 = !{i32 1, !"min_enum_size", i32 4} -!7 = !{!"clang version 12.0.0"} -!8 = distinct !DISubprogram(name: "f", scope: !1, file: !1, type: !10, unit: !0) -!10 = !DISubroutineType(types: !11) -!11 = !{null} -!12 = !{!13} -!13 = !DILocalVariable(name: "a", scope: !8, file: !1, type: !14) -!14 = !DIBasicType(name: "_Float16", size: 16, encoding: DW_ATE_float) -!15 = !DILocation(line: 0, scope: !8) -- 2.7.4