[llvm] [MachineSink] Drop debug info for instructions deleted by sink-and-fold (PR #71443)
Momchil Velikov via llvm-commits
llvm-commits at lists.llvm.org
Mon Nov 6 13:13:09 PST 2023
https://github.com/momchil-velikov created https://github.com/llvm/llvm-project/pull/71443
After performing sink-and-fold over a COPY, the original instruction is
replaced with one that produces its output in the destination of the
copy. Its value is still available (in a hard register), so if there are
debug instructions which refer to the (now deleted) virtual register
they could be updated to refer to the hard register, in principle.
However, it's not clear how to do that, moreover in some cases the debug
instructions may need to be replicated proportionally to the number of
the COPY instructions replaced and in some extreme cases we can end up
with quadratic increase in the number of debug instructions, e.g:
int f(int);
void g(int x) {
int y = x + 1;
int t0 = y;
f(t0);
int t1 = y;
f(t1);
}
>From a54a95b815fba61e2292dc7b0d219f9b6e524f5b Mon Sep 17 00:00:00 2001
From: Momchil Velikov <momchil.velikov at arm.com>
Date: Mon, 6 Nov 2023 18:38:40 +0000
Subject: [PATCH 1/2] [MachineSink] Drop debug info for instructions deleted by
sink-and-fold
After performing sink-and-fold over a COPY, the original instruction is
replaced with one that produces its output in the destination of the
copy. Its value is still available (in a hard register), so if there are
debug instructions which refer to the (now deleted) virtual register
they could be updated to refer to the hard register, in principle.
However, it's not clear how to do that, moreover in some cases the debug
instructions may need to be replicated proportionally to the number of
the COPY instructions replaced and in some extreme cases we can end up
with quadratic increase in the number of debug instructions, e.g:
int f(int);
void g(int x) {
int y = x + 1;
int t0 = y;
f(t0);
int t1 = y;
f(t1);
}
---
llvm/lib/CodeGen/MachineSink.cpp | 25 ++++++++++---------------
1 file changed, 10 insertions(+), 15 deletions(-)
diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp
index d0e119cb7470632..08c0e0ef630cdd4 100644
--- a/llvm/lib/CodeGen/MachineSink.cpp
+++ b/llvm/lib/CodeGen/MachineSink.cpp
@@ -510,6 +510,16 @@ bool MachineSinking::PerformSinkAndFold(MachineInstr &MI,
LLVM_DEBUG(dbgs() << "Sinking copy of"; MI.dump(); dbgs() << "into";
SinkDst->dump());
if (SinkDst->isCopy()) {
+ // TODO: After performing the sink-and-fold, the original instruction is
+ // deleted. Its value is still available (in a hard register), so if there
+ // are debug instructions which refer to the (now deleted) virtual
+ // register they could be updated to refer to the hard register, in
+ // principle. However, it's not clear how to do that, moreover in some
+ // cases the debug instructions may need to be replicated proportionally
+ // to the number of the COPY instructions replaced and in some extreme
+ // cases we can end up with quadratic increase in the number of debug
+ // instructions.
+
// Sink a copy of the instruction, replacing a COPY instruction.
MachineBasicBlock::iterator InsertPt = SinkDst->getIterator();
Register DstReg = SinkDst->getOperand(0).getReg();
@@ -519,21 +529,6 @@ bool MachineSinking::PerformSinkAndFold(MachineInstr &MI,
New = &*std::prev(InsertPt);
if (const DebugLoc &NewLoc = New->getDebugLoc(); !NewLoc)
New->setDebugLoc(SinkDst->getDebugLoc());
- // Sink DBG_VALUEs, which refer to the original instruction's destination
- // (DefReg).
- MachineBasicBlock &SinkMBB = *SinkDst->getParent();
- auto &DbgUsers = SeenDbgUsers[DefReg];
- for (auto &U : DbgUsers) {
- MachineInstr *DbgMI = U.getPointer();
- if (U.getInt())
- continue;
- MachineInstr *NewDbgMI = SinkDst->getMF()->CloneMachineInstr(DbgMI);
- SinkMBB.insertAfter(InsertPt, NewDbgMI);
- for (auto &SrcMO : DbgMI->getDebugOperandsForReg(DefReg)) {
- auto &DstMO = NewDbgMI->getOperand(SrcMO.getOperandNo());
- DstMO.setReg(DstReg);
- }
- }
} else {
// Fold instruction into the addressing mode of a memory instruction.
New = TII->emitLdStWithAddr(*SinkDst, MaybeAM);
>From 910c1dfdf328143a218fb48b1f3eb8fb35b7ce0a Mon Sep 17 00:00:00 2001
From: Momchil Velikov <momchil.velikov at arm.com>
Date: Mon, 6 Nov 2023 19:09:41 +0000
Subject: [PATCH 2/2] Reuse debug location from the COPY.
---
llvm/lib/CodeGen/MachineSink.cpp | 6 +-
.../AArch64/sink-and-fold-dbg-value-crash.mir | 304 ------------------
.../AArch64/sink-and-fold-drop-dbg.mir | 144 +++++++++
.../DebugInfo/Generic/no-empty-child-vars.ll | 9 +-
4 files changed, 152 insertions(+), 311 deletions(-)
delete mode 100644 llvm/test/CodeGen/AArch64/sink-and-fold-dbg-value-crash.mir
create mode 100644 llvm/test/CodeGen/AArch64/sink-and-fold-drop-dbg.mir
diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp
index 08c0e0ef630cdd4..9ed6b22eae972cc 100644
--- a/llvm/lib/CodeGen/MachineSink.cpp
+++ b/llvm/lib/CodeGen/MachineSink.cpp
@@ -524,11 +524,9 @@ bool MachineSinking::PerformSinkAndFold(MachineInstr &MI,
MachineBasicBlock::iterator InsertPt = SinkDst->getIterator();
Register DstReg = SinkDst->getOperand(0).getReg();
TII->reMaterialize(*SinkDst->getParent(), InsertPt, DstReg, 0, MI, *TRI);
- // If the original instruction did not have source location, reuse a one
- // from the COPY.
+ // Reuse the source location from the COPY.
New = &*std::prev(InsertPt);
- if (const DebugLoc &NewLoc = New->getDebugLoc(); !NewLoc)
- New->setDebugLoc(SinkDst->getDebugLoc());
+ New->setDebugLoc(SinkDst->getDebugLoc());
} else {
// Fold instruction into the addressing mode of a memory instruction.
New = TII->emitLdStWithAddr(*SinkDst, MaybeAM);
diff --git a/llvm/test/CodeGen/AArch64/sink-and-fold-dbg-value-crash.mir b/llvm/test/CodeGen/AArch64/sink-and-fold-dbg-value-crash.mir
deleted file mode 100644
index 82dae8a86ea2b77..000000000000000
--- a/llvm/test/CodeGen/AArch64/sink-and-fold-dbg-value-crash.mir
+++ /dev/null
@@ -1,304 +0,0 @@
-# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 3
-# RUN: llc --aarch64-enable-sink-fold=true --run-pass=machine-sink %s -o - | FileCheck %s
---- |
- source_filename = "x.ll"
- target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
- target triple = "aarch64-linux"
-
- %S = type <{ ptr, %T, i64, i64, i32, [4 x i8] }>
- %T = type { ptr, ptr, ptr, ptr, i64 }
-
- define void @f(ptr %p, i1 %c0, i1 %c1) {
- entry:
- %a = getelementptr %S, ptr %p, i64 0, i32 1
- call void @llvm.dbg.value(metadata ptr %a, metadata !4, metadata !DIExpression()), !dbg !10
- br i1 %c0, label %if.then, label %if.end
-
- if.then: ; preds = %entry
- %v0 = tail call ptr @g(ptr %a)
- br i1 %c1, label %exit, label %if.end
-
- if.end: ; preds = %if.then, %entry
- %v1 = load i64, ptr %a, align 8
- br label %exit
-
- exit: ; preds = %if.end, %if.then
- ret void
- }
-
- define ptr @g(ptr) {
- entry:
- br label %if.then
- if.then:
- br label %if.end
- if.end:
- br label %exit
- exit:
- ret ptr null
- }
-
- declare void @llvm.dbg.value(metadata, metadata, metadata) #0
-
- attributes #0 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
-
- !llvm.dbg.cu = !{!0}
- !llvm.module.flags = !{!2, !3}
-
- !0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang ", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
- !1 = !DIFile(filename: "f.c", directory: "/usr/rms")
- !2 = !{i32 7, !"Dwarf Version", i32 4}
- !3 = !{i32 2, !"Debug Info Version", i32 3}
- !4 = !DILocalVariable(name: "x", arg: 1, scope: !5, file: !1, line: 2, type: !8)
- !5 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 2, type: !6, scopeLine: 2, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !9)
- !6 = !DISubroutineType(types: !7)
- !7 = !{!8, !8}
- !8 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
- !9 = !{}
- !10 = !DILocation(line: 2, column: 11, scope: !5)
-
-...
----
-name: f
-alignment: 4
-exposesReturnsTwice: false
-legalized: false
-regBankSelected: false
-selected: false
-failedISel: false
-tracksRegLiveness: true
-hasWinCFI: false
-callsEHReturn: false
-callsUnwindInit: false
-hasEHCatchret: false
-hasEHScopes: false
-hasEHFunclets: false
-isOutlined: false
-debugInstrRef: false
-failsVerification: false
-tracksDebugUserValues: false
-registers:
- - { id: 0, class: gpr64all, preferred-register: '' }
- - { id: 1, class: gpr64common, preferred-register: '' }
- - { id: 2, class: gpr32, preferred-register: '' }
- - { id: 3, class: gpr32, preferred-register: '' }
- - { id: 4, class: gpr32, preferred-register: '' }
- - { id: 5, class: gpr64sp, preferred-register: '' }
- - { id: 6, class: gpr64all, preferred-register: '' }
-liveins:
- - { reg: '$x0', virtual-reg: '%1' }
- - { reg: '$w1', virtual-reg: '%2' }
- - { reg: '$w2', virtual-reg: '%3' }
-frameInfo:
- isFrameAddressTaken: false
- isReturnAddressTaken: false
- hasStackMap: false
- hasPatchPoint: false
- stackSize: 0
- offsetAdjustment: 0
- maxAlignment: 1
- adjustsStack: true
- hasCalls: true
- stackProtector: ''
- functionContext: ''
- maxCallFrameSize: 0
- cvBytesOfCalleeSavedRegisters: 0
- hasOpaqueSPAdjustment: false
- hasVAStart: false
- hasMustTailInVarArgFunc: false
- hasTailCall: false
- localFrameSize: 0
- savePoint: ''
- restorePoint: ''
-fixedStack: []
-stack: []
-entry_values: []
-callSites: []
-debugValueSubstitutions: []
-constants: []
-machineFunctionInfo: {}
-body: |
- ; CHECK-LABEL: name: f
- ; CHECK: bb.0.entry:
- ; CHECK-NEXT: successors: %bb.1(0x40000000), %bb.2(0x40000000)
- ; CHECK-NEXT: liveins: $x0, $w1, $w2
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: [[COPY:%[0-9]+]]:gpr32 = COPY $w2
- ; CHECK-NEXT: [[COPY1:%[0-9]+]]:gpr32 = COPY $w1
- ; CHECK-NEXT: [[COPY2:%[0-9]+]]:gpr64common = COPY $x0
- ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, !4, !DIExpression(), debug-location !10
- ; CHECK-NEXT: TBZW [[COPY1]], 0, %bb.2
- ; CHECK-NEXT: B %bb.1
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: bb.1.if.then:
- ; CHECK-NEXT: successors: %bb.3(0x40000000), %bb.2(0x40000000)
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: [[COPY3:%[0-9]+]]:gpr32 = COPY [[COPY]]
- ; CHECK-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp
- ; CHECK-NEXT: $x0 = ADDXri [[COPY2]], 8, 0
- ; CHECK-NEXT: DBG_VALUE $x0, $noreg, !4, !DIExpression(), debug-location !10
- ; CHECK-NEXT: BL @g, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp, implicit-def $x0
- ; CHECK-NEXT: ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp
- ; CHECK-NEXT: TBNZW [[COPY3]], 0, %bb.3
- ; CHECK-NEXT: B %bb.2
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: bb.2.if.end:
- ; CHECK-NEXT: successors: %bb.3(0x80000000)
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: bb.3.exit:
- ; CHECK-NEXT: RET_ReallyLR
- bb.0.entry:
- successors: %bb.1(0x40000000), %bb.2(0x40000000)
- liveins: $x0, $w1, $w2
-
- %3:gpr32 = COPY $w2
- %2:gpr32 = COPY $w1
- %1:gpr64common = COPY $x0
- %4:gpr32 = COPY %3
- %5:gpr64sp = ADDXri %1, 8, 0
- DBG_VALUE %5, $noreg, !4, !DIExpression(), debug-location !10
- %0:gpr64all = COPY %5
- TBZW %2, 0, %bb.2
- B %bb.1
-
- bb.1.if.then:
- successors: %bb.3(0x40000000), %bb.2(0x40000000)
-
- ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp
- $x0 = COPY %0
- BL @g, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp, implicit-def $x0
- ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp
- TBNZW %4, 0, %bb.3
- B %bb.2
-
- bb.2.if.end:
- successors: %bb.3(0x80000000)
-
-
- bb.3.exit:
- RET_ReallyLR
-
-...
----
-name: g
-alignment: 4
-exposesReturnsTwice: false
-legalized: false
-regBankSelected: false
-selected: false
-failedISel: false
-tracksRegLiveness: true
-hasWinCFI: false
-callsEHReturn: false
-callsUnwindInit: false
-hasEHCatchret: false
-hasEHScopes: false
-hasEHFunclets: false
-isOutlined: false
-debugInstrRef: false
-failsVerification: false
-tracksDebugUserValues: false
-registers:
- - { id: 0, class: gpr64all, preferred-register: '' }
- - { id: 1, class: gpr64common, preferred-register: '' }
- - { id: 2, class: gpr32, preferred-register: '' }
- - { id: 3, class: gpr32, preferred-register: '' }
- - { id: 4, class: gpr32, preferred-register: '' }
- - { id: 5, class: gpr64sp, preferred-register: '' }
- - { id: 6, class: gpr64all, preferred-register: '' }
-liveins:
- - { reg: '$x0', virtual-reg: '%1' }
- - { reg: '$w1', virtual-reg: '%2' }
- - { reg: '$w2', virtual-reg: '%3' }
-frameInfo:
- isFrameAddressTaken: false
- isReturnAddressTaken: false
- hasStackMap: false
- hasPatchPoint: false
- stackSize: 0
- offsetAdjustment: 0
- maxAlignment: 1
- adjustsStack: true
- hasCalls: true
- stackProtector: ''
- functionContext: ''
- maxCallFrameSize: 0
- cvBytesOfCalleeSavedRegisters: 0
- hasOpaqueSPAdjustment: false
- hasVAStart: false
- hasMustTailInVarArgFunc: false
- hasTailCall: false
- localFrameSize: 0
- savePoint: ''
- restorePoint: ''
-fixedStack: []
-stack: []
-entry_values: []
-callSites: []
-debugValueSubstitutions: []
-constants: []
-machineFunctionInfo: {}
-body: |
- ; CHECK-LABEL: name: g
- ; CHECK: bb.0.entry:
- ; CHECK-NEXT: successors: %bb.1(0x40000000), %bb.2(0x40000000)
- ; CHECK-NEXT: liveins: $x0, $w1, $w2
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: [[COPY:%[0-9]+]]:gpr32 = COPY $w2
- ; CHECK-NEXT: [[COPY1:%[0-9]+]]:gpr32 = COPY $w1
- ; CHECK-NEXT: [[COPY2:%[0-9]+]]:gpr64common = COPY $x0
- ; CHECK-NEXT: DBG_VALUE_LIST !4, !DIExpression(), [[COPY]], $noreg, debug-location !10
- ; CHECK-NEXT: TBZW [[COPY1]], 0, %bb.2
- ; CHECK-NEXT: B %bb.1
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: bb.1.if.then:
- ; CHECK-NEXT: successors: %bb.3(0x40000000), %bb.2(0x40000000)
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: [[COPY3:%[0-9]+]]:gpr32 = COPY [[COPY]]
- ; CHECK-NEXT: DBG_VALUE_LIST !4, !DIExpression(), [[COPY3]], $noreg, debug-location !10
- ; CHECK-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp
- ; CHECK-NEXT: $x0 = ADDXri [[COPY2]], 8, 0
- ; CHECK-NEXT: DBG_VALUE_LIST !4, !DIExpression(), [[COPY3]], $x0, debug-location !10
- ; CHECK-NEXT: BL @g, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp, implicit-def $x0
- ; CHECK-NEXT: ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp
- ; CHECK-NEXT: TBNZW [[COPY3]], 0, %bb.3
- ; CHECK-NEXT: B %bb.2
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: bb.2.if.end:
- ; CHECK-NEXT: successors: %bb.3(0x80000000)
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: {{ $}}
- ; CHECK-NEXT: bb.3.exit:
- ; CHECK-NEXT: RET_ReallyLR
- bb.0.entry:
- successors: %bb.1(0x40000000), %bb.2(0x40000000)
- liveins: $x0, $w1, $w2
-
- %3:gpr32 = COPY $w2
- %2:gpr32 = COPY $w1
- %1:gpr64common = COPY $x0
- %4:gpr32 = COPY %3
- %5:gpr64sp = ADDXri %1, 8, 0
- DBG_VALUE_LIST !4, !DIExpression(), %4:gpr32, %5:gpr64sp, debug-location !10
- %0:gpr64all = COPY %5
- TBZW %2, 0, %bb.2
- B %bb.1
-
- bb.1.if.then:
- successors: %bb.3(0x40000000), %bb.2(0x40000000)
-
- ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp
- $x0 = COPY %0
- BL @g, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp, implicit-def $x0
- ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp
- TBNZW %4, 0, %bb.3
- B %bb.2
-
- bb.2.if.end:
- successors: %bb.3(0x80000000)
-
-
- bb.3.exit:
- RET_ReallyLR
-
-...
diff --git a/llvm/test/CodeGen/AArch64/sink-and-fold-drop-dbg.mir b/llvm/test/CodeGen/AArch64/sink-and-fold-drop-dbg.mir
new file mode 100644
index 000000000000000..3cf490474bdc480
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/sink-and-fold-drop-dbg.mir
@@ -0,0 +1,144 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 3
+# RUN: llc --aarch64-enable-sink-fold=true --run-pass=machine-sink %s -o - | FileCheck %s
+--- |
+ source_filename = "dbg.c"
+ target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+ target triple = "aarch64-unknown-linux"
+
+ define dso_local void @g(i32 noundef %x) local_unnamed_addr !dbg !11 {
+ entry:
+ call void @llvm.dbg.value(metadata i32 %x, metadata !16, metadata !DIExpression()), !dbg !20
+ %add = add nsw i32 %x, 1, !dbg !21
+ call void @llvm.dbg.value(metadata i32 %add, metadata !17, metadata !DIExpression()), !dbg !20
+ call void @llvm.dbg.value(metadata i32 %add, metadata !18, metadata !DIExpression()), !dbg !20
+ %call = tail call i32 @f(i32 noundef %add), !dbg !22
+ call void @llvm.dbg.value(metadata i32 %add, metadata !19, metadata !DIExpression()), !dbg !20
+ %call1 = tail call i32 @f(i32 noundef %add), !dbg !23
+ ret void, !dbg !24
+ }
+
+ declare !dbg !25 i32 @f(i32 noundef)
+
+ declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+ !llvm.dbg.cu = !{!0}
+ !llvm.module.flags = !{!2, !3, !4, !5, !6, !7, !8, !9}
+ !llvm.ident = !{!10}
+
+ !0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang version 18.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+ !1 = !DIFile(filename: "dbg.c", directory: "/home/sweet", checksumkind: CSK_MD5, checksum: "b6bd7ad2140c696af9201a17ab73c918")
+ !2 = !{i32 7, !"Dwarf Version", i32 5}
+ !3 = !{i32 2, !"Debug Info Version", i32 3}
+ !4 = !{i32 1, !"wchar_size", i32 4}
+ !5 = !{i32 8, !"PIC Level", i32 2}
+ !6 = !{i32 7, !"PIE Level", i32 2}
+ !7 = !{i32 7, !"uwtable", i32 2}
+ !8 = !{i32 7, !"frame-pointer", i32 1}
+ !9 = !{i32 7, !"debug-info-assignment-tracking", i1 true}
+ !10 = !{!"clang version 18.0.0"}
+ !11 = distinct !DISubprogram(name: "g", scope: !1, file: !1, line: 3, type: !12, scopeLine: 3, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+ !12 = !DISubroutineType(types: !13)
+ !13 = !{null, !14}
+ !14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+ !15 = !{!16, !17, !18, !19}
+ !16 = !DILocalVariable(name: "x", arg: 1, scope: !11, file: !1, line: 3, type: !14)
+ !17 = !DILocalVariable(name: "y", scope: !11, file: !1, line: 4, type: !14)
+ !18 = !DILocalVariable(name: "t0", scope: !11, file: !1, line: 6, type: !14)
+ !19 = !DILocalVariable(name: "t1", scope: !11, file: !1, line: 9, type: !14)
+ !20 = !DILocation(line: 0, scope: !11)
+ !21 = !DILocation(line: 4, column: 13, scope: !11)
+ !22 = !DILocation(line: 7, column: 3, scope: !11)
+ !23 = !DILocation(line: 10, column: 3, scope: !11)
+ !24 = !DILocation(line: 11, column: 1, scope: !11)
+ !25 = !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !26, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
+ !26 = !DISubroutineType(types: !27)
+ !27 = !{!14, !14}
+
+...
+---
+name: g
+alignment: 4
+exposesReturnsTwice: false
+legalized: false
+regBankSelected: false
+selected: false
+failedISel: false
+tracksRegLiveness: true
+hasWinCFI: false
+callsEHReturn: false
+callsUnwindInit: false
+hasEHCatchret: false
+hasEHScopes: false
+hasEHFunclets: false
+isOutlined: false
+debugInstrRef: false
+failsVerification: false
+tracksDebugUserValues: false
+registers:
+ - { id: 0, class: gpr32common, preferred-register: '' }
+ - { id: 1, class: gpr32sp, preferred-register: '' }
+ - { id: 2, class: gpr32all, preferred-register: '' }
+liveins:
+ - { reg: '$w0', virtual-reg: '%0' }
+frameInfo:
+ isFrameAddressTaken: false
+ isReturnAddressTaken: false
+ hasStackMap: false
+ hasPatchPoint: false
+ stackSize: 0
+ offsetAdjustment: 0
+ maxAlignment: 1
+ adjustsStack: true
+ hasCalls: true
+ stackProtector: ''
+ functionContext: ''
+ maxCallFrameSize: 0
+ cvBytesOfCalleeSavedRegisters: 0
+ hasOpaqueSPAdjustment: false
+ hasVAStart: false
+ hasMustTailInVarArgFunc: false
+ hasTailCall: true
+ localFrameSize: 0
+ savePoint: ''
+ restorePoint: ''
+fixedStack: []
+stack: []
+entry_values: []
+callSites: []
+debugValueSubstitutions: []
+constants: []
+machineFunctionInfo: {}
+body: |
+ bb.0.entry:
+ liveins: $w0
+
+ ; CHECK-LABEL: name: g
+ ; CHECK: liveins: $w0
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: DBG_VALUE $w0, $noreg, !16, !DIExpression(), debug-location !20
+ ; CHECK-NEXT: [[COPY:%[0-9]+]]:gpr32common = COPY $w0
+ ; CHECK-NEXT: DBG_VALUE [[COPY]], $noreg, !16, !DIExpression(), debug-location !20
+ ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, !17, !DIExpression(), debug-location !20
+ ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, !18, !DIExpression(), debug-location !20
+ ; CHECK-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp, debug-location !22
+ ; CHECK-NEXT: $w0 = nsw ADDWri [[COPY]], 1, 0, debug-location !22
+ ; CHECK-NEXT: BL @f, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $w0, implicit-def $sp, implicit-def $w0, debug-location !22
+ ; CHECK-NEXT: ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp, debug-location !22
+ ; CHECK-NEXT: DBG_VALUE $noreg, $noreg, !19, !DIExpression(), debug-location !20
+ ; CHECK-NEXT: $w0 = nsw ADDWri [[COPY]], 1, 0, debug-location !23
+ ; CHECK-NEXT: TCRETURNdi @f, 0, csr_aarch64_aapcs, implicit $sp, implicit $w0, debug-location !23
+ DBG_VALUE $w0, $noreg, !16, !DIExpression(), debug-location !20
+ %0:gpr32common = COPY $w0
+ DBG_VALUE %0, $noreg, !16, !DIExpression(), debug-location !20
+ %1:gpr32sp = nsw ADDWri %0, 1, 0, debug-location !21
+ DBG_VALUE %1, $noreg, !17, !DIExpression(), debug-location !20
+ DBG_VALUE %1, $noreg, !18, !DIExpression(), debug-location !20
+ ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp, debug-location !22
+ $w0 = COPY %1, debug-location !22
+ BL @f, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $w0, implicit-def $sp, implicit-def $w0, debug-location !22
+ ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp, debug-location !22
+ DBG_VALUE %1, $noreg, !19, !DIExpression(), debug-location !20
+ $w0 = COPY %1, debug-location !23
+ TCRETURNdi @f, 0, csr_aarch64_aapcs, implicit $sp, implicit $w0, debug-location !23
+
+...
diff --git a/llvm/test/DebugInfo/Generic/no-empty-child-vars.ll b/llvm/test/DebugInfo/Generic/no-empty-child-vars.ll
index 1399b68b9b7f184..2b533968e330021 100644
--- a/llvm/test/DebugInfo/Generic/no-empty-child-vars.ll
+++ b/llvm/test/DebugInfo/Generic/no-empty-child-vars.ll
@@ -68,11 +68,14 @@
; CHECK: DW_TAG_inlined_subroutine
; CHECK: NULL
+; NOTE: Instructions below changed from `add` to `mul` to make them more expensive
+; and unlikely to be sunk to replace COPYs into a return value register.
+
; Function Attrs: norecurse nounwind readnone uwtable willreturn
define dso_local i32 @foo(i32 %bar) local_unnamed_addr !dbg !7 {
entry:
call void @llvm.dbg.value(metadata i32 %bar, metadata !12, metadata !DIExpression()), !dbg !14
- %add = add nsw i32 %bar, 12, !dbg !15
+ %add = mul nsw i32 %bar, 12, !dbg !15
call void @llvm.dbg.value(metadata i32 %add, metadata !13, metadata !DIExpression()), !dbg !14
ret i32 %add, !dbg !16
}
@@ -80,7 +83,7 @@ entry:
; Function Attrs: norecurse nounwind readnone uwtable willreturn
define dso_local i32 @qux(i32 %quux) local_unnamed_addr !dbg !17 {
entry:
- %add.i = add nsw i32 %quux, 12, !dbg !24
+ %add.i = mul nsw i32 %quux, 12, !dbg !24
ret i32 %add.i, !dbg !25
}
@@ -89,7 +92,7 @@ define dso_local i32 @croix(i32 %quux) local_unnamed_addr !dbg !26 {
entry:
call void @llvm.dbg.value(metadata i32 undef, metadata !28, metadata !DIExpression()), !dbg !30
call void @llvm.dbg.value(metadata i32 undef, metadata !12, metadata !DIExpression()), !dbg !31
- %add.i = add nsw i32 %quux, 12, !dbg !33
+ %add.i = mul nsw i32 %quux, 12, !dbg !33
call void @llvm.dbg.value(metadata i32 undef, metadata !13, metadata !DIExpression()), !dbg !31
call void @llvm.dbg.value(metadata i32 undef, metadata !29, metadata !DIExpression()), !dbg !30
ret i32 %add.i, !dbg !34
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