[AArch64] Fix an incorrect handling of debug values in MachineSink (#68107)

Author: momchil-velikov

llvm/lib/CodeGen/MachineSink.cpp

@@ -528,7 +528,10 @@ bool MachineSinking::PerformSinkAndFold(MachineInstr &MI,
           continue;
         MachineInstr *NewDbgMI = SinkDst->getMF()->CloneMachineInstr(DbgMI);
         SinkMBB.insertAfter(InsertPt, NewDbgMI);
-        NewDbgMI->getOperand(0).setReg(DstReg);
+        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.

llvm/test/CodeGen/AArch64/sink-and-fold-dbg-value-crash.mir

@@ -26,7 +26,16 @@
     ret void
   }
 
-  declare ptr @g(ptr)
+  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
 
@@ -170,3 +179,126 @@ body:             |
     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
+
+...