#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetLowering.h"
+#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/Config/llvm-config.h"
InvalidKind = 0,
RegisterKind,
SpillLocKind,
- ImmediateKind
+ ImmediateKind,
+ EntryValueKind
} Kind = InvalidKind;
/// The value location. Stored separately to avoid repeatedly
const ConstantInt *CImm;
} Loc;
- VarLoc(const MachineInstr &MI, LexicalScopes &LS)
- : Var(MI), MI(MI), UVS(MI.getDebugLoc(), LS) {
+ VarLoc(const MachineInstr &MI, LexicalScopes &LS,
+ VarLocKind K = InvalidKind)
+ : Var(MI), MI(MI), UVS(MI.getDebugLoc(), LS), Kind(K) {
static_assert((sizeof(Loc) == sizeof(uint64_t)),
"hash does not cover all members of Loc");
assert(MI.isDebugValue() && "not a DBG_VALUE");
assert(MI.getNumOperands() == 4 && "malformed DBG_VALUE");
if (int RegNo = isDbgValueDescribedByReg(MI)) {
- Kind = RegisterKind;
+ assert((!EntryValueKind || RegNo) &&
+ "entry values must be register locations");
+ if (Kind != EntryValueKind)
+ Kind = RegisterKind;
Loc.RegNo = RegNo;
} else if (MI.getOperand(0).isImm()) {
Kind = ImmediateKind;
return 0;
}
+ bool isEntryValueKind() const {
+ return Kind == EntryValueKind;
+ }
+
/// Determine whether the lexical scope of this value's debug location
/// dominates MBB.
bool dominates(MachineBasicBlock &MBB) const { return UVS.dominates(&MBB); }
/// This operator guarantees that VarLocs are sorted by Variable first.
bool operator<(const VarLoc &Other) const {
- if (Var == Other.Var)
- return Loc.Hash < Other.Loc.Hash;
- return Var < Other.Var;
+ return std::tie(Var, Kind, Loc.Hash) <
+ std::tie(Other.Var, Other.Kind, Other.Loc.Hash);
}
};
+ using DebugParamMap = SmallDenseMap<const DILocalVariable *, MachineInstr *>;
using VarLocMap = UniqueVector<VarLoc>;
using VarLocSet = SparseBitVector<>;
using VarLocInMBB = SmallDenseMap<const MachineBasicBlock *, VarLocSet>;
VarLocMap &VarLocIDs);
void transferSpillOrRestoreInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
VarLocMap &VarLocIDs, TransferMap &Transfers);
+ void emitEntryValues(MachineInstr &MI, OpenRangesSet &OpenRanges,
+ VarLocMap &VarLocIDs, TransferMap &Transfers,
+ DebugParamMap &DebugEntryVals,
+ SparseBitVector<> &KillSet);
void transferRegisterCopy(MachineInstr &MI, OpenRangesSet &OpenRanges,
VarLocMap &VarLocIDs, TransferMap &Transfers);
void transferRegisterDef(MachineInstr &MI, OpenRangesSet &OpenRanges,
- const VarLocMap &VarLocIDs);
+ VarLocMap &VarLocIDs, TransferMap &Transfers,
+ DebugParamMap &DebugEntryVals);
bool transferTerminatorInst(MachineInstr &MI, OpenRangesSet &OpenRanges,
VarLocInMBB &OutLocs, const VarLocMap &VarLocIDs);
bool process(MachineInstr &MI, OpenRangesSet &OpenRanges,
VarLocInMBB &OutLocs, VarLocMap &VarLocIDs,
- TransferMap &Transfers, bool transferChanges,
- OverlapMap &OverlapFragments, VarToFragments &SeenFragments);
+ TransferMap &Transfers, DebugParamMap &DebugEntryVals,
+ bool transferChanges, OverlapMap &OverlapFragments,
+ VarToFragments &SeenFragments);
void accumulateFragmentMap(MachineInstr &MI, VarToFragments &SeenFragments,
OverlapMap &OLapMap);
OpenRanges.erase(V);
// Add the VarLoc to OpenRanges from this DBG_VALUE.
+ VarLoc::VarLocKind Kind = VarLoc::InvalidKind;
unsigned ID;
- if (isDbgValueDescribedByReg(MI) || MI.getOperand(0).isImm() ||
- MI.getOperand(0).isFPImm() || MI.getOperand(0).isCImm()) {
+
+ auto FinishVarLoc = [&] (const MachineInstr &MI, VarLoc::VarLocKind &Kind) {
// Use normal VarLoc constructor for registers and immediates.
- VarLoc VL(MI, LS);
+ VarLoc VL(MI, LS, Kind);
ID = VarLocIDs.insert(VL);
OpenRanges.insert(ID, VL.Var);
+ };
+
+ if (isDbgValueDescribedByReg(MI)) {
+ Kind = VarLoc::RegisterKind;
+ const DIExpression *Expr = MI.getDebugExpression();
+ if (Expr->isEntryValue())
+ Kind = VarLoc::EntryValueKind;
+ FinishVarLoc(MI, Kind);
+ } else if (MI.getOperand(0).isImm() ||
+ MI.getOperand(0).isFPImm() || MI.getOperand(0).isCImm()) {
+ Kind = VarLoc::ImmediateKind;
+ FinishVarLoc(MI, Kind);
} else if (MI.hasOneMemOperand()) {
// It's a stack spill -- fetch spill base and offset.
VarLoc::SpillLoc SpillLocation = extractSpillBaseRegAndOffset(MI);
}
}
+void LiveDebugValues::emitEntryValues(MachineInstr &MI,
+ OpenRangesSet &OpenRanges,
+ VarLocMap &VarLocIDs,
+ TransferMap &Transfers,
+ DebugParamMap &DebugEntryVals,
+ SparseBitVector<> &KillSet) {
+ MachineFunction *MF = MI.getParent()->getParent();
+ for (unsigned ID : KillSet) {
+ if (!VarLocIDs[ID].Var.getVar()->isParameter())
+ continue;
+
+ const MachineInstr *CurrDebugInstr = &VarLocIDs[ID].MI;
+
+ // If parameter's DBG_VALUE is not in the map that means we can't
+ // generate parameter's entry value.
+ if (!DebugEntryVals.count(CurrDebugInstr->getDebugVariable()))
+ continue;
+
+ auto ParamDebugInstr = DebugEntryVals[CurrDebugInstr->getDebugVariable()];
+ DIExpression *NewExpr = DIExpression::prepend(
+ ParamDebugInstr->getDebugExpression(), DIExpression::EntryValue);
+ MachineInstr *EntryValDbgMI =
+ BuildMI(*MF, ParamDebugInstr->getDebugLoc(), ParamDebugInstr->getDesc(),
+ ParamDebugInstr->isIndirectDebugValue(),
+ ParamDebugInstr->getOperand(0).getReg(),
+ ParamDebugInstr->getDebugVariable(), NewExpr);
+
+ if (ParamDebugInstr->isIndirectDebugValue())
+ EntryValDbgMI->getOperand(1).setImm(
+ ParamDebugInstr->getOperand(1).getImm());
+
+ Transfers.push_back({&MI, EntryValDbgMI});
+ VarLoc VL(*EntryValDbgMI, LS, VarLoc::EntryValueKind);
+ unsigned EntryValLocID = VarLocIDs.insert(VL);
+ OpenRanges.insert(EntryValLocID, VL.Var);
+ }
+}
+
/// Create new TransferDebugPair and insert it in \p Transfers. The VarLoc
/// with \p OldVarID should be deleted form \p OpenRanges and replaced with
/// new VarLoc. If \p NewReg is different than default zero value then the
}
/// A definition of a register may mark the end of a range.
-void LiveDebugValues::transferRegisterDef(MachineInstr &MI,
- OpenRangesSet &OpenRanges,
- const VarLocMap &VarLocIDs) {
+void LiveDebugValues::transferRegisterDef(
+ MachineInstr &MI, OpenRangesSet &OpenRanges, VarLocMap &VarLocIDs,
+ TransferMap &Transfers, DebugParamMap &DebugEntryVals) {
MachineFunction *MF = MI.getMF();
const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
}
}
OpenRanges.erase(KillSet, VarLocIDs);
+
+ if (auto *TPC = getAnalysisIfAvailable<TargetPassConfig>()) {
+ auto &TM = TPC->getTM<TargetMachine>();
+ if (TM.Options.EnableDebugEntryValues)
+ emitEntryValues(MI, OpenRanges, VarLocIDs, Transfers, DebugEntryVals,
+ KillSet);
+ }
}
/// Decide if @MI is a spill instruction and return true if it is. We use 2
/// This routine creates OpenRanges and OutLocs.
bool LiveDebugValues::process(MachineInstr &MI, OpenRangesSet &OpenRanges,
VarLocInMBB &OutLocs, VarLocMap &VarLocIDs,
- TransferMap &Transfers, bool transferChanges,
+ TransferMap &Transfers, DebugParamMap &DebugEntryVals,
+ bool transferChanges,
OverlapMap &OverlapFragments,
VarToFragments &SeenFragments) {
bool Changed = false;
transferDebugValue(MI, OpenRanges, VarLocIDs);
- transferRegisterDef(MI, OpenRanges, VarLocIDs);
+ transferRegisterDef(MI, OpenRanges, VarLocIDs, Transfers,
+ DebugEntryVals);
if (transferChanges) {
transferRegisterCopy(MI, OpenRanges, VarLocIDs, Transfers);
transferSpillOrRestoreInst(MI, OpenRanges, VarLocIDs, Transfers);
enum : bool { dontTransferChanges = false, transferChanges = true };
+ // Besides parameter's modification, check whether a DBG_VALUE is inlined
+ // in order to deduce whether the variable that it tracks comes from
+ // a different function. If that is the case we can't track its entry value.
+ auto IsUnmodifiedFuncParam = [&](const MachineInstr &MI) {
+ auto *DIVar = MI.getDebugVariable();
+ return DIVar->isParameter() && DIVar->isNotModified() &&
+ !MI.getDebugLoc()->getInlinedAt();
+ };
+
+ const TargetLowering *TLI = MF.getSubtarget().getTargetLowering();
+ unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
+ unsigned FP = TRI->getFrameRegister(MF);
+ auto IsRegOtherThanSPAndFP = [&](const MachineOperand &Op) -> bool {
+ return Op.isReg() && Op.getReg() != SP && Op.getReg() != FP;
+ };
+
+ // Working set of currently collected debug variables mapped to DBG_VALUEs
+ // representing candidates for production of debug entry values.
+ DebugParamMap DebugEntryVals;
+
+ MachineBasicBlock &First_MBB = *(MF.begin());
+ // Only in the case of entry MBB collect DBG_VALUEs representing
+ // function parameters in order to generate debug entry values for them.
+ // Currently, we generate debug entry values only for parameters that are
+ // unmodified throughout the function and located in a register.
+ // TODO: Add support for parameters that are described as fragments.
+ // TODO: Add support for modified arguments that can be expreseed
+ // by using its entry value.
+ for (auto &MI : First_MBB)
+ if (MI.isDebugValue() && IsUnmodifiedFuncParam(MI) &&
+ !MI.isIndirectDebugValue() && IsRegOtherThanSPAndFP(MI.getOperand(0)) &&
+ !DebugEntryVals.count(MI.getDebugVariable()) &&
+ !MI.getDebugExpression()->isFragment())
+ DebugEntryVals[MI.getDebugVariable()] = &MI;
+
// Initialize every mbb with OutLocs.
// We are not looking at any spill instructions during the initial pass
// over the BBs. The LiveDebugVariables pass has already created DBG_VALUE
// within the BB in which the spill occurs.
for (auto &MBB : MF) {
for (auto &MI : MBB) {
- process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers,
+ process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers, DebugEntryVals,
dontTransferChanges, OverlapFragments, SeenFragments);
}
+ // Add any entry DBG_VALUE instructions necessitated by parameter
+ // clobbering.
+ for (auto &TR : Transfers) {
+ MBB.insertAfter(MachineBasicBlock::iterator(*TR.TransferInst),
+ TR.DebugInst);
+ }
+ Transfers.clear();
}
auto hasNonArtificialLocation = [](const MachineInstr &MI) -> bool {
for (auto &MI : *MBB)
OLChanged |=
process(MI, OpenRanges, OutLocs, VarLocIDs, Transfers,
- transferChanges, OverlapFragments, SeenFragments);
+ DebugEntryVals, transferChanges, OverlapFragments,
+ SeenFragments);
// Add any DBG_VALUE instructions necessitated by spills.
for (auto &TR : Transfers)
--- /dev/null
+# RUN: llc -debug-entry-values -run-pass=livedebugvalues -march=x86-64 -o - %s | FileCheck %s
+#
+#extern void fn2(int);
+#
+#__attribute__((noinline))
+#void
+#fn1 (int x, int y) {
+# int u = x + y;
+# if (x > 1)
+# u += 1;
+# else
+# u += 2;
+# int a = 7;
+# fn2 (a);
+# u --;
+#}
+# CHECK: DBG_VALUE $edi, $noreg, !14, !DIExpression(DW_OP_entry_value, 1), debug-location {{.*}}
+# CHECK: DBG_VALUE $esi, $noreg, !15, !DIExpression(DW_OP_entry_value, 1), debug-location {{.*}}
+
+--- |
+ ; ModuleID = 'test.c'
+ source_filename = "test.c"
+ target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+ ; Function Attrs: noinline nounwind uwtable
+ define dso_local void @fn1(i32 %x, i32 %y) local_unnamed_addr !dbg !9 {
+ entry:
+ call void @llvm.dbg.value(metadata i32 %x, metadata !14, metadata !DIExpression()), !dbg !18
+ call void @llvm.dbg.value(metadata i32 %y, metadata !15, metadata !DIExpression()), !dbg !18
+ call void @llvm.dbg.value(metadata i32 7, metadata !17, metadata !DIExpression()), !dbg !18
+ tail call void @fn2(i32 7), !dbg !18
+ ret void, !dbg !18
+ }
+
+ declare !dbg !4 dso_local void @fn2(i32) local_unnamed_addr
+
+ ; Function Attrs: nounwind readnone speculatable
+ declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+
+ !llvm.dbg.cu = !{!0}
+ !llvm.module.flags = !{!5, !6, !7}
+ !llvm.ident = !{!8}
+
+ !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, nameTableKind: None)
+ !1 = !DIFile(filename: "test.c", directory: "/dir")
+ !2 = !{}
+ !3 = !{!4}
+ !4 = !DISubprogram(name: "fn2", scope: !1, file: !1, line: 11, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
+ !5 = !{i32 2, !"Dwarf Version", i32 4}
+ !6 = !{i32 2, !"Debug Info Version", i32 3}
+ !7 = !{i32 1, !"wchar_size", i32 4}
+ !8 = !{!"clang version 9.0.0"}
+ !9 = distinct !DISubprogram(name: "fn1", scope: !1, file: !1, line: 15, type: !10, scopeLine: 15, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !13)
+ !10 = !DISubroutineType(types: !11)
+ !11 = !{null, !12, !12}
+ !12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+ !13 = !{!14, !15, !16, !17}
+ !14 = !DILocalVariable(name: "x", arg: 1, scope: !9, file: !1, line: 15, type: !12, flags: DIFlagArgumentNotModified)
+ !15 = !DILocalVariable(name: "y", arg: 2, scope: !9, file: !1, line: 15, type: !12, flags: DIFlagArgumentNotModified)
+ !16 = !DILocalVariable(name: "u", scope: !9, file: !1, line: 16, type: !12, flags: DIFlagArgumentNotModified)
+ !17 = !DILocalVariable(name: "a", scope: !9, file: !1, line: 21, type: !12, flags: DIFlagArgumentNotModified)
+ !18 = !DILocation(line: 15, column: 10, scope: !9)
+
+...
+---
+name: fn1
+alignment: 4
+tracksRegLiveness: true
+liveins: []
+body: |
+ bb.0.entry:
+ DBG_VALUE $edi, $noreg, !14, !DIExpression(), debug-location !18
+ DBG_VALUE $esi, $noreg, !15, !DIExpression(), debug-location !18
+ DBG_VALUE 7, $noreg, !17, !DIExpression(), debug-location !18
+ $edi = MOV32ri 7, debug-location !18
+ TAILJMPd64 @fn2, csr_64, implicit $rsp, implicit $ssp, implicit $rsp, implicit $ssp, implicit killed $edi, debug-location !18
+
+...
--- /dev/null
+# RUN: llc -debug-entry-values -run-pass=livedebugvalues -march=x86-64 -o - %s| FileCheck %s
+#
+#int global;
+#int foo(int p, int q, int r) {
+# global = p + 1;
+# asm __volatile("" : : : "edi", "esi", "edx");
+# return 123;
+#}
+#
+# Verify that DW_OP_entry_values are generated for parameters with multiple
+# DBG_VALUEs at entry block.
+# CHECK: DBG_VALUE $edi, $noreg, !{{.*}}, !DIExpression(DW_OP_entry_value, 1), debug-location {{.*}}
+# CHECK: DBG_VALUE $edx, $noreg, !{{.*}}, !DIExpression(DW_OP_entry_value, 1), debug-location {{.*}}
+# CHECK: DBG_VALUE $esi, $noreg, !{{.*}}, !DIExpression(DW_OP_entry_value, 1), debug-location {{.*}}
+
+--- |
+ ; ModuleID = 'multiple-param-dbg-value-entry.ll'
+ source_filename = "multiple-param-dbg-value-entry.c"
+ target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+ @global = common dso_local local_unnamed_addr global i32 0, align 4, !dbg !0
+
+ define dso_local i32 @foo(i32 %p, i32 %q, i32 %r) local_unnamed_addr !dbg !11 {
+ entry:
+ call void @llvm.dbg.value(metadata i32 %p, metadata !15, metadata !DIExpression()), !dbg !18
+ call void @llvm.dbg.value(metadata i32 %q, metadata !16, metadata !DIExpression()), !dbg !18
+ call void @llvm.dbg.value(metadata i32 %r, metadata !17, metadata !DIExpression()), !dbg !18
+ %add = add nsw i32 %p, 1, !dbg !18
+ store i32 %add, i32* @global, align 4, !dbg !18
+ tail call void asm sideeffect "", "~{edi},~{esi},~{edx},~{dirflag},~{fpsr},~{flags}"(), !dbg !18, !srcloc !19
+ ret i32 123, !dbg !18
+ }
+
+ ; Function Attrs: nounwind readnone speculatable
+ declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+ !llvm.dbg.cu = !{!2}
+ !llvm.module.flags = !{!7, !8, !9}
+ !llvm.ident = !{!10}
+
+ !0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+ !1 = distinct !DIGlobalVariable(name: "global", scope: !2, file: !3, line: 8, type: !6, isLocal: false, isDefinition: true)
+ !2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 9.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+ !3 = !DIFile(filename: "multiple-param-dbg-value-entry.c", directory: "/")
+ !4 = !{}
+ !5 = !{!0}
+ !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+ !7 = !{i32 2, !"Dwarf Version", i32 4}
+ !8 = !{i32 2, !"Debug Info Version", i32 3}
+ !9 = !{i32 1, !"wchar_size", i32 4}
+ !10 = !{!"clang version 9.0.0 "}
+ !11 = distinct !DISubprogram(name: "foo", scope: !3, file: !3, line: 9, type: !12, scopeLine: 9, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !14)
+ !12 = !DISubroutineType(types: !13)
+ !13 = !{!6, !6, !6, !6}
+ !14 = !{!15, !16, !17}
+ !15 = !DILocalVariable(name: "p", arg: 1, scope: !11, file: !3, line: 9, type: !6, flags: DIFlagArgumentNotModified)
+ !16 = !DILocalVariable(name: "q", arg: 2, scope: !11, file: !3, line: 9, type: !6, flags: DIFlagArgumentNotModified)
+ !17 = !DILocalVariable(name: "r", arg: 3, scope: !11, file: !3, line: 9, type: !6, flags: DIFlagArgumentNotModified)
+ !18 = !DILocation(line: 9, column: 13, scope: !11)
+ !19 = !{i32 213}
+
+...
+---
+name: foo
+alignment: 4
+tracksRegLiveness: true
+liveins:
+ - { reg: '$edi' }
+body: |
+ bb.0.entry:
+ liveins: $edi
+
+ DBG_VALUE $edi, $noreg, !15, !DIExpression(), debug-location !18
+ DBG_VALUE $edi, $noreg, !15, !DIExpression(), debug-location !18
+ DBG_VALUE $esi, $noreg, !16, !DIExpression(), debug-location !18
+ DBG_VALUE $edx, $noreg, !17, !DIExpression(), debug-location !18
+ renamable $edi = nsw INC32r killed renamable $edi, implicit-def dead $eflags, debug-location !18
+ MOV32mr $rip, 1, $noreg, @global, $noreg, killed renamable $edi, debug-location !18 :: (store 4 into @global)
+ INLINEASM &"", 1, 12, implicit-def dead early-clobber $edi, 12, implicit-def dead early-clobber $esi, 12, implicit-def dead early-clobber $edx, 12, implicit-def dead early-clobber $df, 12, implicit-def dead early-clobber $fpsw, 12, implicit-def dead early-clobber $eflags, !19, debug-location !18
+ $eax = MOV32ri 123, debug-location !18
+ RETQ killed $eax, debug-location !18
+
+...
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