[llvm] r314974 - [DebugInfo] Insert DEBUG_VALUEs after each register redefinition
Karl-Johan Karlsson via llvm-commits
llvm-commits at lists.llvm.org
Thu Oct 5 01:37:31 PDT 2017
Author: karka
Date: Thu Oct 5 01:37:31 2017
New Revision: 314974
URL: http://llvm.org/viewvc/llvm-project?rev=314974&view=rev
Log:
[DebugInfo] Insert DEBUG_VALUEs after each register redefinition
Summary:
When reinserting debug values after register allocation, make sure to
insert debug values after each redefinition of debug value register in
the slot index range. The reason for this is that DwarfDebug will end
the range of a debug variable when the physical reg is defined. For
instructions with e.g. tied operands this result in prematurely ended
debug range.
This resolves pr34545
Patch by Karl-Johan Karlsson and Bjorn Pettersson
Reviewers: rnk, aprantl
Reviewed By: rnk
Subscribers: bjope, llvm-commits
Differential Revision: https://reviews.llvm.org/D38229
Added:
llvm/trunk/test/DebugInfo/X86/pr34545.ll
Modified:
llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp
Modified: llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp?rev=314974&r1=314973&r2=314974&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp Thu Oct 5 01:37:31 2017
@@ -166,9 +166,11 @@ class UserValue {
SmallSet<SlotIndex, 2> trimmedDefs;
/// insertDebugValue - Insert a DBG_VALUE into MBB at Idx for LocNo.
- void insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx,
+ void insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
+ SlotIndex StopIdx,
DbgValueLocation Loc, bool Spilled, LiveIntervals &LIS,
- const TargetInstrInfo &TII);
+ const TargetInstrInfo &TII,
+ const TargetRegisterInfo &TRI);
/// splitLocation - Replace OldLocNo ranges with NewRegs ranges where NewRegs
/// is live. Returns true if any changes were made.
@@ -306,7 +308,8 @@ public:
/// emitDebugValues - Recreate DBG_VALUE instruction from data structures.
void emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
- const TargetInstrInfo &TRI,
+ const TargetInstrInfo &TII,
+ const TargetRegisterInfo &TRI,
const BitVector &SpilledLocations);
/// getDebugLoc - Return DebugLoc of this UserValue.
@@ -1055,8 +1058,7 @@ void UserValue::rewriteLocations(VirtReg
}
}
-/// findInsertLocation - Find an iterator for inserting a DBG_VALUE
-/// instruction.
+/// Find an iterator for inserting a DBG_VALUE instruction.
static MachineBasicBlock::iterator
findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx,
LiveIntervals &LIS) {
@@ -1079,11 +1081,41 @@ findInsertLocation(MachineBasicBlock *MB
std::next(MachineBasicBlock::iterator(MI));
}
-void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx,
+/// Find an iterator for inserting the next DBG_VALUE instruction
+/// (or end if no more insert locations found).
+static MachineBasicBlock::iterator
+findNextInsertLocation(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator I,
+ SlotIndex StopIdx, MachineOperand &LocMO,
+ LiveIntervals &LIS,
+ const TargetRegisterInfo &TRI) {
+ if (!LocMO.isReg())
+ return MBB->instr_end();
+ unsigned Reg = LocMO.getReg();
+
+ // Find the next instruction in the MBB that define the register Reg.
+ while (I != MBB->end()) {
+ if (!LIS.isNotInMIMap(*I) &&
+ SlotIndex::isEarlierEqualInstr(StopIdx, LIS.getInstructionIndex(*I)))
+ break;
+ if (I->definesRegister(Reg, &TRI))
+ // The insert location is directly after the instruction/bundle.
+ return std::next(I);
+ ++I;
+ }
+ return MBB->end();
+}
+
+void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
+ SlotIndex StopIdx,
DbgValueLocation Loc, bool Spilled,
LiveIntervals &LIS,
- const TargetInstrInfo &TII) {
- MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
+ const TargetInstrInfo &TII,
+ const TargetRegisterInfo &TRI) {
+ SlotIndex MBBEndIdx = LIS.getMBBEndIdx(&*MBB);
+ // Only search within the current MBB.
+ StopIdx = (MBBEndIdx < StopIdx) ? MBBEndIdx : StopIdx;
+ MachineBasicBlock::iterator I = findInsertLocation(MBB, StartIdx, LIS);
MachineOperand &MO = locations[Loc.locNo()];
++NumInsertedDebugValues;
@@ -1104,18 +1136,25 @@ void UserValue::insertDebugValue(Machine
assert((!Spilled || MO.isFI()) && "a spilled location must be a frame index");
- MachineInstrBuilder MIB =
+ do {
+ MachineInstrBuilder MIB =
BuildMI(*MBB, I, getDebugLoc(), TII.get(TargetOpcode::DBG_VALUE))
.add(MO);
- if (IsIndirect)
- MIB.addImm(0U);
- else
- MIB.addReg(0U, RegState::Debug);
- MIB.addMetadata(Variable).addMetadata(Expr);
+ if (IsIndirect)
+ MIB.addImm(0U);
+ else
+ MIB.addReg(0U, RegState::Debug);
+ MIB.addMetadata(Variable).addMetadata(Expr);
+
+ // Continue and insert DBG_VALUES after every redefinition of register
+ // associated with the debug value within the range
+ I = findNextInsertLocation(MBB, I, StopIdx, MO, LIS, TRI);
+ } while (I != MBB->end());
}
void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
const TargetInstrInfo &TII,
+ const TargetRegisterInfo &TRI,
const BitVector &SpilledLocations) {
MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
@@ -1136,17 +1175,17 @@ void UserValue::emitDebugValues(VirtRegM
SlotIndex MBBEnd = LIS.getMBBEndIdx(&*MBB);
DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
- insertDebugValue(&*MBB, Start, Loc, Spilled, LIS, TII);
+ insertDebugValue(&*MBB, Start, Stop, Loc, Spilled, LIS, TII, TRI);
// This interval may span multiple basic blocks.
// Insert a DBG_VALUE into each one.
- while(Stop > MBBEnd) {
+ while (Stop > MBBEnd) {
// Move to the next block.
Start = MBBEnd;
if (++MBB == MFEnd)
break;
MBBEnd = LIS.getMBBEndIdx(&*MBB);
DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
- insertDebugValue(&*MBB, Start, Loc, Spilled, LIS, TII);
+ insertDebugValue(&*MBB, Start, Stop, Loc, Spilled, LIS, TII, TRI);
}
DEBUG(dbgs() << '\n');
if (MBB == MFEnd)
@@ -1165,7 +1204,7 @@ void LDVImpl::emitDebugValues(VirtRegMap
for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
DEBUG(userValues[i]->print(dbgs(), TRI));
userValues[i]->rewriteLocations(*VRM, *TRI, SpilledLocations);
- userValues[i]->emitDebugValues(VRM, *LIS, *TII, SpilledLocations);
+ userValues[i]->emitDebugValues(VRM, *LIS, *TII, *TRI, SpilledLocations);
}
EmitDone = true;
}
Added: llvm/trunk/test/DebugInfo/X86/pr34545.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/pr34545.ll?rev=314974&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/pr34545.ll (added)
+++ llvm/trunk/test/DebugInfo/X86/pr34545.ll Thu Oct 5 01:37:31 2017
@@ -0,0 +1,58 @@
+; RUN: llc -O1 -filetype=asm -mtriple x86_64-unknown-linux-gnu -mcpu=x86-64 -o - %s -stop-after=livedebugvars | FileCheck %s
+
+; CHECK: %eax = MOV32rm
+; CHECK: DBG_VALUE %eax
+; CHECK: %eax = SHL32rCL killed %eax
+; CHECK: DBG_VALUE %eax
+; CHECK: DBG_VALUE %rsp, 0, !{{[0-9]+}}, !DIExpression(DW_OP_constu, 4, DW_OP_minus)
+; CHECK: DBG_VALUE %eax
+; CHECK: %eax = SHL32rCL killed %eax
+; CHECK: DBG_VALUE %eax
+; CHECK: RETQ %eax
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at var = local_unnamed_addr global i32 8, !dbg !0
+ at sc = local_unnamed_addr global i32 1, !dbg !6
+
+define i32 @main() local_unnamed_addr !dbg !14 {
+entry:
+ %0 = load i32, i32* @var
+ tail call void @llvm.dbg.value(metadata i32 %0, metadata !18, metadata !DIExpression()), !dbg !20
+ %1 = load i32, i32* @sc
+ %shl = shl i32 %0, %1
+ tail call void @llvm.dbg.value(metadata i32 %shl, metadata !18, metadata !DIExpression()), !dbg !20
+ tail call void asm sideeffect "", "~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15},~{dirflag},~{fpsr},~{flags}"(), !srcloc !25
+ %2 = load i32, i32* @sc
+ %shl2 = shl i32 %shl, %2
+ tail call void @llvm.dbg.value(metadata i32 %shl2, metadata !18, metadata !DIExpression()), !dbg !20
+ store i32 %shl2, i32* @var
+ ret i32 %shl2
+}
+
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!10, !11, !12}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "var", scope: !2, file: !3, line: 10, type: !9, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 6.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5)
+!3 = !DIFile(filename: "bar.c", directory: ".")
+!4 = !{}
+!5 = !{!0, !6}
+!6 = !DIGlobalVariableExpression(var: !7, expr: !DIExpression())
+!7 = distinct !DIGlobalVariable(name: "sc", scope: !2, file: !3, line: 11, type: !8, isLocal: false, isDefinition: true)
+!8 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !{i32 2, !"Dwarf Version", i32 4}
+!11 = !{i32 2, !"Debug Info Version", i32 3}
+!12 = !{i32 1, !"wchar_size", i32 4}
+!14 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 12, type: !15, isLocal: false, isDefinition: true, scopeLine: 12, isOptimized: true, unit: !2, variables: !17)
+!15 = !DISubroutineType(types: !16)
+!16 = !{!9}
+!17 = !{!18}
+!18 = !DILocalVariable(name: "bazinga", scope: !14, file: !3, line: 13, type: !9)
+!20 = !DILocation(line: 13, column: 7, scope: !14)
+!25 = !{i32 -2147471481}
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