Index: llvm/lib/CodeGen/RegisterCoalescer.cpp =================================================================== --- llvm/lib/CodeGen/RegisterCoalescer.cpp +++ llvm/lib/CodeGen/RegisterCoalescer.cpp @@ -1557,7 +1557,9 @@ // If the virtual SrcReg is completely eliminated, update all DBG_VALUEs // to describe DstReg instead. if (MRI->use_nodbg_empty(SrcReg)) { - for (MachineOperand &UseMO : MRI->use_operands(SrcReg)) { + for (MachineRegisterInfo::use_iterator UI = MRI->use_begin(SrcReg); + UI != MRI->use_end();) { + MachineOperand &UseMO = *UI++; MachineInstr *UseMI = UseMO.getParent(); if (UseMI->isDebugValue()) { if (Register::isPhysicalRegister(DstReg)) Index: llvm/test/DebugInfo/MIR/X86/regcoalescer.mir =================================================================== --- llvm/test/DebugInfo/MIR/X86/regcoalescer.mir +++ llvm/test/DebugInfo/MIR/X86/regcoalescer.mir @@ -27,9 +27,10 @@ !16 = !{!7} !17 = !{!18} !18 = !DILocalVariable(name: "bazinga", scope: !14, file: !1, line: 13, type: !7) - !19 = !DILocation(line: 14, column: 11, scope: !14) - !20 = !DILocation(line: 13, column: 7, scope: !14) - !21 = !DILocation(line: 16, column: 3, scope: !14) + !19 = !DILocalVariable(name: "bazinga2", scope: !14, file: !1, line: 13, type: !7) + !20 = !DILocation(line: 14, column: 11, scope: !14) + !21 = !DILocation(line: 13, column: 7, scope: !14) + !22 = !DILocation(line: 16, column: 3, scope: !14) ... --- @@ -39,12 +40,14 @@ - { id: 0, class: gr32, preferred-register: '' } body: | bb.0.entry: - %0 = MOV32r0 implicit-def dead $eflags, debug-location !19 - DBG_VALUE %0, _, !18, !DIExpression(), debug-location !20 - $eax = COPY killed %0, debug-location !21 - RET 0, killed $eax, debug-location !21 + %0 = MOV32r0 implicit-def dead $eflags, debug-location !20 + DBG_VALUE %0, _, !18, !DIExpression(), debug-location !21 + DBG_VALUE %0, _, !19, !DIExpression(), debug-location !22 + $eax = COPY killed %0, debug-location !22 + RET 0, killed $eax, debug-location !22 ... # CHECK: $eax = MOV32r0 # CHECK-NEXT: DBG_VALUE $eax +# CHECK-NEXT: DBG_VALUE $eax