[llvm] [MachineSink][AArch64] Preserve debug location when rematerialising an instruction to replace a COPY (PR #72685)
Momchil Velikov via llvm-commits
llvm-commits at lists.llvm.org
Fri Nov 17 10:05:39 PST 2023
https://github.com/momchil-velikov created https://github.com/llvm/llvm-project/pull/72685
Fixes a regression in `tools/lldb-dap/optimized/TestDAP_optimized.py` caused by enabling "sink-and-fold" in MachineSink.
>From 6a1e5c98ce311c0040f7ec387f2a636c2b308b5c Mon Sep 17 00:00:00 2001
From: Momchil Velikov <momchil.velikov at arm.com>
Date: Fri, 17 Nov 2023 17:54:17 +0000
Subject: [PATCH] [MachineSink][AArch64] Preserve debug location when
rematerialising an instruction to replace a COPY
Fixes a regression in `tools/lldb-dap/optimized/TestDAP_optimized.py`
caused by enabling "sink-and-fold" in MachineSink.
---
llvm/lib/CodeGen/MachineSink.cpp | 4 +-
.../AArch64/sink-and-fold-drop-dbg.mir | 4 +-
.../sink-and-fold-preserve-debugloc.mir | 223 ++++++++++++++++++
3 files changed, 226 insertions(+), 5 deletions(-)
create mode 100644 llvm/test/CodeGen/AArch64/sink-and-fold-preserve-debugloc.mir
diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp
index 9ed6b22eae972cc..48f5a21406f08a8 100644
--- a/llvm/lib/CodeGen/MachineSink.cpp
+++ b/llvm/lib/CodeGen/MachineSink.cpp
@@ -506,7 +506,7 @@ bool MachineSinking::PerformSinkAndFold(MachineInstr &MI,
MRI->clearKillFlags(UsedRegB);
for (auto &[SinkDst, MaybeAM] : SinkInto) {
- MachineInstr *New = nullptr;
+ [[maybe_unused]] MachineInstr *New = nullptr;
LLVM_DEBUG(dbgs() << "Sinking copy of"; MI.dump(); dbgs() << "into";
SinkDst->dump());
if (SinkDst->isCopy()) {
@@ -524,9 +524,7 @@ 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);
- // Reuse the source location from the COPY.
New = &*std::prev(InsertPt);
- 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-drop-dbg.mir b/llvm/test/CodeGen/AArch64/sink-and-fold-drop-dbg.mir
index 3cf490474bdc480..b0280f268f3ff94 100644
--- a/llvm/test/CodeGen/AArch64/sink-and-fold-drop-dbg.mir
+++ b/llvm/test/CodeGen/AArch64/sink-and-fold-drop-dbg.mir
@@ -121,11 +121,11 @@ body: |
; 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: $w0 = nsw ADDWri [[COPY]], 1, 0, debug-location !21
; 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: $w0 = nsw ADDWri [[COPY]], 1, 0, debug-location !21
; 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
diff --git a/llvm/test/CodeGen/AArch64/sink-and-fold-preserve-debugloc.mir b/llvm/test/CodeGen/AArch64/sink-and-fold-preserve-debugloc.mir
new file mode 100644
index 000000000000000..be5737d297b2904
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/sink-and-fold-preserve-debugloc.mir
@@ -0,0 +1,223 @@
+# RUN: llc %s -run-pass=machine-sink --aarch64-enable-sink-fold=true -o - | FileCheck %s
+--- |
+ target triple = "aarch64-linux"
+
+ @.str = private unnamed_addr constant [12 x i8] c"result: %d\0A\00", align 1, !dbg !0
+
+ define i32 @foo(i32 %x, i32 %y) !dbg !18 {
+ entry:
+ %add = add i32 %x, 3, !dbg !25
+ %add1 = add i32 %add, %y, !dbg !26
+ ret i32 %add1, !dbg !27
+ }
+
+ define i32 @baz(i32 %y) !dbg !28 {
+ entry:
+ %add1.i = add i32 %y, 23, !dbg !34
+ tail call void @bar(ptr nonnull @.str, i32 %add1.i), !dbg !36
+ ret i32 0, !dbg !37
+ }
+
+ declare !dbg !38 void @bar(ptr noundef, i32 noundef)
+
+ !llvm.dbg.cu = !{!7}
+ !llvm.module.flags = !{!9, !10, !11, !12, !13, !14, !15, !16}
+ !llvm.ident = !{!17}
+
+ !0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+ !1 = distinct !DIGlobalVariable(scope: null, file: !2, line: 9, type: !3, isLocal: true, isDefinition: true)
+ !2 = !DIFile(filename: "m.c", directory: "/home/chill")
+ !3 = !DICompositeType(tag: DW_TAG_array_type, baseType: !4, size: 96, elements: !5)
+ !4 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_unsigned_char)
+ !5 = !{!6}
+ !6 = !DISubrange(count: 12)
+ !7 = distinct !DICompileUnit(language: DW_LANG_C11, file: !2, producer: "clang version 18.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, globals: !8, splitDebugInlining: false, nameTableKind: None)
+ !8 = !{!0}
+ !9 = !{i32 7, !"Dwarf Version", i32 5}
+ !10 = !{i32 2, !"Debug Info Version", i32 3}
+ !11 = !{i32 1, !"wchar_size", i32 4}
+ !12 = !{i32 8, !"PIC Level", i32 2}
+ !13 = !{i32 7, !"PIE Level", i32 2}
+ !14 = !{i32 7, !"uwtable", i32 2}
+ !15 = !{i32 7, !"frame-pointer", i32 1}
+ !16 = !{i32 7, !"debug-info-assignment-tracking", i1 true}
+ !17 = !{!"clang version 18.0.0"}
+ !18 = distinct !DISubprogram(name: "foo", scope: !2, file: !2, line: 1, type: !19, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !7, retainedNodes: !22)
+ !19 = !DISubroutineType(types: !20)
+ !20 = !{!21, !21, !21}
+ !21 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+ !22 = !{!23, !24}
+ !23 = !DILocalVariable(name: "x", arg: 1, scope: !18, file: !2, line: 1, type: !21)
+ !24 = !DILocalVariable(name: "y", arg: 2, scope: !18, file: !2, line: 1, type: !21)
+ !25 = !DILocation(line: 2, column: 12, scope: !18)
+ !26 = !DILocation(line: 2, column: 16, scope: !18)
+ !27 = !DILocation(line: 2, column: 3, scope: !18)
+ !28 = distinct !DISubprogram(name: "baz", scope: !2, file: !2, line: 7, type: !29, scopeLine: 7, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !7, retainedNodes: !31)
+ !29 = !DISubroutineType(types: !30)
+ !30 = !{!21, !21}
+ !31 = !{!32, !33}
+ !32 = !DILocalVariable(name: "y", arg: 1, scope: !28, file: !2, line: 7, type: !21)
+ !33 = !DILocalVariable(name: "result", scope: !28, file: !2, line: 8, type: !21)
+ !34 = !DILocation(line: 2, column: 16, scope: !18, inlinedAt: !35)
+ !35 = distinct !DILocation(line: 8, column: 16, scope: !28)
+ !36 = !DILocation(line: 9, column: 3, scope: !28)
+ !37 = !DILocation(line: 10, column: 3, scope: !28)
+ !38 = !DISubprogram(name: "bar", scope: !2, file: !2, line: 5, type: !39, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
+ !39 = !DISubroutineType(types: !40)
+ !40 = !{null, !41, !21}
+ !41 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !42, size: 64)
+ !42 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !4)
+
+...
+---
+name: foo
+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: gpr32, preferred-register: '' }
+ - { id: 1, class: gpr32, preferred-register: '' }
+ - { id: 2, class: gpr32common, preferred-register: '' }
+ - { id: 3, class: gpr32sp, preferred-register: '' }
+liveins:
+ - { reg: '$w0', virtual-reg: '%0' }
+ - { reg: '$w1', virtual-reg: '%1' }
+frameInfo:
+ isFrameAddressTaken: false
+ isReturnAddressTaken: false
+ hasStackMap: false
+ hasPatchPoint: false
+ stackSize: 0
+ offsetAdjustment: 0
+ maxAlignment: 1
+ adjustsStack: false
+ hasCalls: false
+ 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: |
+ bb.0.entry:
+ liveins: $w0, $w1
+
+ ; CHECK-LABEL: name: foo
+
+ ; Check the source location of the ADDWri was reused (usually the
+ ; copy to $w0 carries the same debug location as the return)
+
+ ; CHECK: $w0 = ADDWri {{.*}}, 3, 0, debug-location !26
+ ; CHECK-NEXT: RET_ReallyLR implicit $w0, debug-location !27
+ %1:gpr32 = COPY $w1
+ %0:gpr32 = COPY $w0
+ %2:gpr32common = ADDWrr %0, %1, debug-location !25
+ $w0 = ADDWri %2, 3, 0, debug-location !26
+ RET_ReallyLR implicit $w0, debug-location !27
+
+...
+---
+name: baz
+alignment: 4
+exposesReturnsTwice: false
+legalized: false
+regBankSelected: false
+selected: false
+failedISel: false
+tracksRegLiveness: true
+hasWinCFI: false
+callsEHReturn: false
+callsUnwindInit: false
+hasEHCatchret: false
+hasEHScopes: false
+hasEHFunclets: false
+isOutlined: false
+debugInstrRef: false
+failsVerification: false
+tracksDebugUserValues: false
+registers:
+ - { id: 0, class: gpr32common, preferred-register: '' }
+ - { id: 1, class: gpr32sp, preferred-register: '' }
+ - { id: 2, class: gpr64common, preferred-register: '' }
+ - { id: 3, class: gpr32all, preferred-register: '' }
+liveins:
+ - { reg: '$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: false
+ localFrameSize: 0
+ savePoint: ''
+ restorePoint: ''
+fixedStack: []
+stack: []
+entry_values: []
+callSites: []
+debugValueSubstitutions: []
+constants: []
+machineFunctionInfo: {}
+body: |
+ bb.0.entry:
+ liveins: $w0
+
+ ; CHECK-LABEL: name: baz
+
+ ; Check the source location of the ADDWri was reused (usually the
+ ; copy to $w1 carries the same debug location as the BL)
+
+ ; CHECK: $x0 = COPY {{.*}}, debug-location !36
+ ; CHECK-NEXT: $w1 = ADDWri {{.*}}, 23, 0, debug-location !34
+ ; CHECK-NEXT: BL @bar, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit $w1, implicit-def $sp, debug-location !36
+
+ %0:gpr32common = COPY $w0
+ ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp, debug-location !36
+ %2:gpr64common = MOVaddr target-flags(aarch64-page) @.str, target-flags(aarch64-pageoff, aarch64-nc) @.str, debug-location !36
+ $x0 = COPY %2, debug-location !36
+ $w1 = ADDWri %0, 23, 0, debug-location !34
+ BL @bar, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit $w1, implicit-def $sp, debug-location !36
+ ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp, debug-location !36
+ %3:gpr32all = COPY $wzr
+ $w0 = COPY %3, debug-location !37
+ RET_ReallyLR implicit $w0, debug-location !37
+
+...
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