Reapply "[DebugInfo] Fix updateDbgUsersToReg to support DBG_VALUE_LIST"

Previous crashes caused by this patch were the result of machine
subregisters being incorrectly handled in updateDbgUsersToReg; this has
been fixed by using RegUnits to determine overlapping registers, instead
of using the register values directly.

Differential Revision: https://reviews.llvm.org/D101523

This reverts commit 7ca26c5fa2.
This commit is contained in:
Stephen Tozer 2021-05-10 14:00:01 +01:00
parent 5af3a6645f
commit fdb055f4f1
3 changed files with 226 additions and 8 deletions

View File

@ -823,12 +823,27 @@ public:
/// updateDbgUsersToReg - Update a collection of DBG_VALUE instructions
/// to refer to the designated register.
void updateDbgUsersToReg(Register Reg,
ArrayRef<MachineInstr*> Users) const {
void updateDbgUsersToReg(MCRegister OldReg, MCRegister NewReg,
ArrayRef<MachineInstr *> Users) const {
SmallSet<MCRegister, 4> OldRegUnits;
for (MCRegUnitIterator RUI(OldReg, getTargetRegisterInfo()); RUI.isValid();
++RUI)
OldRegUnits.insert(*RUI);
for (MachineInstr *MI : Users) {
assert(MI->isDebugInstr());
assert(MI->getOperand(0).isReg());
MI->getOperand(0).setReg(Reg);
assert(MI->isDebugValue());
for (auto &Op : MI->debug_operands()) {
if (Op.isReg()) {
for (MCRegUnitIterator RUI(OldReg, getTargetRegisterInfo());
RUI.isValid(); ++RUI) {
if (OldRegUnits.contains(*RUI)) {
Op.setReg(NewReg);
break;
}
}
}
}
assert(MI->hasDebugOperandForReg(NewReg) &&
"Expected debug value to have some overlap with OldReg");
}
}

View File

@ -294,7 +294,7 @@ private:
SmallSetVector<MachineInstr *, 8> MaybeDeadCopies;
/// Multimap tracking debug users in current BB
DenseMap<MachineInstr*, SmallVector<MachineInstr*, 2>> CopyDbgUsers;
DenseMap<MachineInstr *, SmallSet<MachineInstr *, 2>> CopyDbgUsers;
CopyTracker Tracker;
@ -321,7 +321,7 @@ void MachineCopyPropagation::ReadRegister(MCRegister Reg, MachineInstr &Reader,
LLVM_DEBUG(dbgs() << "MCP: Copy is used - not dead: "; Copy->dump());
MaybeDeadCopies.remove(Copy);
} else {
CopyDbgUsers[Copy].push_back(&Reader);
CopyDbgUsers[Copy].insert(&Reader);
}
}
}
@ -734,7 +734,11 @@ void MachineCopyPropagation::ForwardCopyPropagateBlock(MachineBasicBlock &MBB) {
// Update matching debug values, if any.
assert(MaybeDead->isCopy());
Register SrcReg = MaybeDead->getOperand(1).getReg();
MRI->updateDbgUsersToReg(SrcReg, CopyDbgUsers[MaybeDead]);
Register DestReg = MaybeDead->getOperand(0).getReg();
SmallVector<MachineInstr *> MaybeDeadDbgUsers(
CopyDbgUsers[MaybeDead].begin(), CopyDbgUsers[MaybeDead].end());
MRI->updateDbgUsersToReg(DestReg.asMCReg(), SrcReg.asMCReg(),
MaybeDeadDbgUsers);
MaybeDead->eraseFromParent();
Changed = true;

View File

@ -0,0 +1,199 @@
# RUN: llc %s -run-pass=machine-cp -o - | FileCheck %s --implicit-check-not=DBG_VALUE
## Ensure that when the destination register of a copy instruction is used by a
## DBG_VALUE/DBG_VALUE_LIST, and then that instruction is deleted during copy
## propagation, the debug use is updated to the source register.
# CHECK: ![[VAR_V:[0-9]+]] = !DILocalVariable(name: "v"
# CHECK-LABEL: body:
# CHECK: DBG_VALUE $r0, $noreg, ![[VAR_V]], !DIExpression()
# CHECK: DBG_VALUE_LIST ![[VAR_V]], !DIExpression(DW_OP_LLVM_arg, 0, DW_OP_LLVM_arg, 1, DW_OP_constu, 4, DW_OP_mul, DW_OP_plus, DW_OP_stack_value), $r0, 0
--- |
target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
target triple = "arm-unknown-linux-gnueabi"
%struct.atomic_t.0.6.15.24.48.51.54.57 = type { i32 }
%struct.mm_struct.2.8.17.26.50.53.56.59 = type { %struct.anon.1.7.16.25.49.52.55.58 }
%struct.anon.1.7.16.25.49.52.55.58 = type { i32 }
@dup_mm_err = external dso_local local_unnamed_addr global i32, align 4, !dbg !0
declare dso_local i32 @atomic_long_read(%struct.atomic_t.0.6.15.24.48.51.54.57*) local_unnamed_addr #0
declare dso_local i32 @get_mm_counter(%struct.mm_struct.2.8.17.26.50.53.56.59*, i32) local_unnamed_addr #0
define dso_local i32 @dup_mm() local_unnamed_addr !dbg !16 {
entry:
%call = tail call i32 bitcast (i32 (...)* @kmem_cache_alloc to i32 (i32)*)(i32 0)
br i1 undef, label %cleanup, label %if.end
if.end: ; preds = %entry
%tobool1.not = icmp eq i32 undef, 0
br i1 %tobool1.not, label %if.end3, label %free_pt
if.end3: ; preds = %if.end
call void @llvm.dbg.value(metadata !DIArgList(i32 %call, i32 0), metadata !30, metadata !DIExpression(DW_OP_LLVM_arg, 0, DW_OP_LLVM_arg, 1, DW_OP_constu, 4, DW_OP_mul, DW_OP_plus, DW_OP_stack_value)), !dbg !40
%0 = load volatile i32, i32* undef, align 4
br label %cleanup
free_pt: ; preds = %if.end
store i32 0, i32* undef, align 4
br label %cleanup
cleanup: ; preds = %free_pt, %if.end3, %entry
%retval.0 = phi i32 [ %call, %if.end3 ], [ 0, %entry ], [ 0, %free_pt ]
ret i32 %retval.0
}
declare dso_local i32 @kmem_cache_alloc(...) local_unnamed_addr
declare void @llvm.dbg.label(metadata)
declare void @llvm.dbg.value(metadata, metadata, metadata)
!llvm.dbg.cu = !{!2}
!llvm.module.flags = !{!14, !15}
!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
!1 = distinct !DIGlobalVariable(name: "dup_mm_err", scope: !2, file: !3, line: 5, type: !12, isLocal: false, isDefinition: true)
!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 13.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, retainedTypes: !9, globals: !13, splitDebugInlining: false, nameTableKind: None)
!3 = !DIFile(filename: "machine-cp-updates-dbg-reg.ll", directory: "/")
!4 = !{!5}
!5 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !3, line: 4, baseType: !6, size: 32, elements: !7)
!6 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
!7 = !{!8}
!8 = !DIEnumerator(name: "MM_SHMEMPAGES", value: 0, isUnsigned: true)
!9 = !{!10}
!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !11, size: 32)
!11 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: !12)
!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!13 = !{!0}
!14 = !{i32 2, !"Debug Info Version", i32 3}
!15 = !{i32 1, !"min_enum_size", i32 4}
!16 = distinct !DISubprogram(name: "dup_mm", scope: !3, file: !3, line: 14, type: !17, scopeLine: 14, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !19)
!17 = !DISubroutineType(types: !18)
!18 = !{!12}
!19 = !{!20, !28, !29}
!20 = !DILocalVariable(name: "mm", scope: !16, file: !3, line: 15, type: !21)
!21 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !22, size: 32)
!22 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "mm_struct", file: !3, line: 7, size: 32, elements: !23)
!23 = !{!24}
!24 = !DIDerivedType(tag: DW_TAG_member, scope: !22, file: !3, line: 8, baseType: !25, size: 32)
!25 = distinct !DICompositeType(tag: DW_TAG_structure_type, scope: !22, file: !3, line: 8, size: 32, elements: !26)
!26 = !{!27}
!27 = !DIDerivedType(tag: DW_TAG_member, name: "binfmt", scope: !25, file: !3, line: 9, baseType: !12, size: 32)
!28 = !DILabel(scope: !16, name: "free_pt", file: !3, line: 22)
!29 = !DILabel(scope: !16, name: "fail_nomem", file: !3, line: 24)
!30 = !DILocalVariable(name: "v", arg: 1, scope: !31, file: !3, line: 6, type: !34)
!31 = distinct !DISubprogram(name: "atomic_long_read", scope: !3, file: !3, line: 6, type: !32, scopeLine: 6, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !39)
!32 = !DISubroutineType(types: !33)
!33 = !{!12, !34}
!34 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !35, size: 32)
!35 = !DIDerivedType(tag: DW_TAG_typedef, name: "atomic_t", file: !3, line: 3, baseType: !36)
!36 = distinct !DICompositeType(tag: DW_TAG_structure_type, file: !3, line: 1, size: 32, elements: !37)
!37 = !{!38}
!38 = !DIDerivedType(tag: DW_TAG_member, name: "counter", scope: !36, file: !3, line: 2, baseType: !12, size: 32)
!39 = !{!30}
!40 = !DILocation(line: 0, scope: !31, inlinedAt: !41)
!41 = distinct !DILocation(line: 12, column: 3, scope: !42, inlinedAt: !48)
!42 = distinct !DISubprogram(name: "get_mm_counter", scope: !3, file: !3, line: 11, type: !43, scopeLine: 11, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !45)
!43 = !DISubroutineType(types: !44)
!44 = !{!22, !21, !12}
!45 = !{!46, !47}
!46 = !DILocalVariable(name: "mm", arg: 1, scope: !42, file: !3, line: 11, type: !21)
!47 = !DILocalVariable(name: "member", arg: 2, scope: !42, file: !3, line: 11, type: !12)
!48 = distinct !DILocation(line: 20, column: 3, scope: !16)
...
---
name: dup_mm
alignment: 4
exposesReturnsTwice: false
legalized: false
regBankSelected: false
selected: false
failedISel: false
tracksRegLiveness: true
hasWinCFI: false
registers: []
liveins: []
frameInfo:
isFrameAddressTaken: false
isReturnAddressTaken: false
hasStackMap: false
hasPatchPoint: false
stackSize: 8
offsetAdjustment: 0
maxAlignment: 4
adjustsStack: true
hasCalls: true
stackProtector: ''
maxCallFrameSize: 0
cvBytesOfCalleeSavedRegisters: 0
hasOpaqueSPAdjustment: false
hasVAStart: false
hasMustTailInVarArgFunc: false
hasTailCall: false
localFrameSize: 0
savePoint: ''
restorePoint: ''
fixedStack: []
stack:
- { id: 0, name: '', type: spill-slot, offset: -4, size: 4, alignment: 4,
stack-id: default, callee-saved-register: '$lr', callee-saved-restored: false,
debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
- { id: 1, name: '', type: spill-slot, offset: -8, size: 4, alignment: 4,
stack-id: default, callee-saved-register: '$r4', callee-saved-restored: true,
debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
callSites: []
debugValueSubstitutions: []
constants: []
machineFunctionInfo: {}
body: |
bb.0.entry:
successors: %bb.4(0x40000000), %bb.1(0x40000000)
liveins: $r4, $lr
$sp = frame-setup STMDB_UPD $sp, 14 /* CC::al */, $noreg, killed $r4, killed $lr
frame-setup CFI_INSTRUCTION def_cfa_offset 8
frame-setup CFI_INSTRUCTION offset $lr, -4
frame-setup CFI_INSTRUCTION offset $r4, -8
renamable $r4 = MOVi 0, 14 /* CC::al */, $noreg, $noreg
$r0 = MOVi 0, 14 /* CC::al */, $noreg, $noreg
BL @kmem_cache_alloc, csr_aapcs, implicit-def dead $lr, implicit $sp, implicit $r0, implicit-def $sp, implicit-def $r0
CMPri renamable $r4, 0, 14 /* CC::al */, $noreg, implicit-def $cpsr
Bcc %bb.4, 1 /* CC::ne */, killed $cpsr
bb.1.if.end:
successors: %bb.2(0x30000000), %bb.3(0x50000000)
liveins: $r0
renamable $r4 = MOVi 0, 14 /* CC::al */, $noreg, $noreg
CMPri renamable $r4, 0, 14 /* CC::al */, $noreg, implicit-def $cpsr
Bcc %bb.3, 1 /* CC::ne */, killed $cpsr
bb.2.if.end3:
liveins: $r0
dead renamable $r1 = LDRi12 undef renamable $r0, 0, 14 /* CC::al */, $noreg :: (volatile load 4 from `i32* undef`)
renamable $r4 = COPY killed renamable $r0
DBG_VALUE $r4, $noreg, !30, !DIExpression(), debug-location !40
DBG_VALUE_LIST !30, !DIExpression(DW_OP_LLVM_arg, 0, DW_OP_LLVM_arg, 1, DW_OP_constu, 4, DW_OP_mul, DW_OP_plus, DW_OP_stack_value), $r4, 0, debug-location !40
$r0 = COPY killed renamable $r4
$sp = frame-destroy LDMIA_RET $sp, 14 /* CC::al */, $noreg, def $r4, def $pc, implicit $r0
bb.3.free_pt:
successors: %bb.4(0x80000000)
liveins: $r4
STRi12 renamable $r4, undef renamable $r0, 0, 14 /* CC::al */, $noreg :: (store 4 into `i32* undef`)
bb.4.cleanup:
liveins: $r4
$r0 = COPY killed renamable $r4
$sp = frame-destroy LDMIA_RET $sp, 14 /* CC::al */, $noreg, def $r4, def $pc, implicit $r0
...