[llvm] [CodeGen][RAGreedy] Inform LiveDebugVariables about snippets spilled by InlineSpiller. (PR #109962)

[Bevin Hansson via llvm-commits]

================
@@ -0,0 +1,167 @@
+# RUN: llc -O3 -mtriple i386 -start-before=greedy -stop-after=livedebugvars %s -o - | FileCheck %s
+
+# There should be multiple debug values for this variable after regalloc. The
+# value has been spilled, but we shouldn't lose track of the location because
+# of this.
+
+# CHECK-COUNT-4: DBG_VALUE $ebp, 0, !6, !DIExpression(DW_OP_constu, 16, DW_OP_minus), debug-location !10
+
+--- |
+  
+  define void @main() #0 !dbg !4 {
+  entry:
+  #dbg_value(i32 undef, !6, !DIExpression(), !10)
+    ret void
+  }
+  
+  attributes #0 = { "frame-pointer"="all" }
+  
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!3}
+  
+  !0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang version 20.0.0git.prerel", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, globals: !2, splitDebugInlining: false, nameTableKind: None)
+  !1 = !DIFile(filename: "xx.c", directory: "/path", checksumkind: CSK_MD5, checksum: "c4b2fc62bca9171ad484c91fb78b8842")
+  !2 = !{}
+  !3 = !{i32 2, !"Debug Info Version", i32 3}
+  !4 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 20, type: !5, scopeLine: 20, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
+  !5 = !DISubroutineType(types: !2)
+  !6 = !DILocalVariable(name: "flag", arg: 2, scope: !7, file: !1, line: 8, type: !9)
+  !7 = distinct !DISubprogram(name: "transparent_crc", scope: !1, file: !1, line: 8, type: !8, scopeLine: 8, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
+  !8 = distinct !DISubroutineType(types: !2)
+  !9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !10 = !DILocation(line: 0, scope: !7, inlinedAt: !11)
+  !11 = distinct !DILocation(line: 28, column: 3, scope: !4)
+
+...
+---
+name:            main
+alignment:       16
+exposesReturnsTwice: false
+legalized:       false
+regBankSelected: false
+selected:        false
+failedISel:      false
+tracksRegLiveness: true
+hasWinCFI:       false
+noPhis:          true
+isSSA:           false
+noVRegs:         false
+callsEHReturn:   false
+callsUnwindInit: false
+hasEHCatchret:   false
+hasEHScopes:     false
+hasEHFunclets:   false
+isOutlined:      false
+debugInstrRef:   false
+failsVerification: false
+tracksDebugUserValues: false
+registers:
+  - { id: 0, class: gr32_abcd, preferred-register: '' }
+  - { id: 1, class: gr32, preferred-register: '' }
+  - { id: 2, class: gr32, preferred-register: '' }
+  - { id: 3, class: gr32, preferred-register: '' }
+  - { id: 4, class: gr32, preferred-register: '' }
+  - { id: 5, class: gr8, preferred-register: '' }
+  - { id: 6, class: gr32, preferred-register: '' }
+  - { id: 7, class: gr32, preferred-register: '' }
+  - { id: 8, class: gr8, preferred-register: '' }
+  - { id: 9, class: gr32, preferred-register: '' }
+  - { id: 10, class: gr32, preferred-register: '' }
+  - { id: 11, class: gr32, preferred-register: '' }
+  - { id: 12, class: gr32, preferred-register: '' }
+  - { id: 13, class: gr32, preferred-register: '' }
+  - { id: 14, class: gr32, preferred-register: '' }
+  - { id: 15, class: gr32, preferred-register: '' }
+  - { id: 16, class: gr32, preferred-register: '' }
+  - { id: 17, class: gr32, preferred-register: '' }
+  - { id: 18, class: gr32_abcd, preferred-register: '' }
+  - { id: 19, class: gr32, preferred-register: '' }
+liveins:         []
+frameInfo:
+  isFrameAddressTaken: false
+  isReturnAddressTaken: false
+  hasStackMap:     false
+  hasPatchPoint:   false
+  stackSize:       0
+  offsetAdjustment: 0
+  maxAlignment:    4
+  adjustsStack:    false
+  hasCalls:        false
+  stackProtector:  ''
+  functionContext: ''
+  maxCallFrameSize: 4294967295
+  cvBytesOfCalleeSavedRegisters: 0
+  hasOpaqueSPAdjustment: false
+  hasVAStart:      false
+  hasMustTailInVarArgFunc: false
+  hasTailCall:     false
+  isCalleeSavedInfoValid: false
+  localFrameSize:  0
+  savePoint:       ''
+  restorePoint:    ''
+fixedStack:
+  - { id: 0, type: default, offset: 12, size: 4, alignment: 4, stack-id: default, 
+      isImmutable: true, isAliased: false, callee-saved-register: '', callee-saved-restored: true, 
+      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
+  - { id: 1, type: default, offset: 8, size: 1, alignment: 4, stack-id: default, 
+      isImmutable: true, isAliased: false, callee-saved-register: '', callee-saved-restored: true, 
+      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
+  - { id: 2, type: default, offset: 4, size: 4, alignment: 4, stack-id: default, 
+      isImmutable: true, isAliased: false, callee-saved-register: '', callee-saved-restored: true, 
+      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
+  - { id: 3, type: default, offset: 0, size: 4, alignment: 4, stack-id: default, 
+      isImmutable: true, isAliased: false, callee-saved-register: '', callee-saved-restored: true, 
+      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
+stack:           []
+entry_values:    []
+callSites:       []
+debugValueSubstitutions: []
+constants:       []
+machineFunctionInfo:
+  amxProgModel:    None
+body:             |
+  bb.0:
+    successors: %bb.2(0x80000000)
+  
+    %6:gr32 = MOV32rm %fixed-stack.0, 1, $noreg, 0, $noreg :: (load (s32) from %fixed-stack.0)
+    %5:gr8 = MOV8rm %fixed-stack.1, 1, $noreg, 0, $noreg :: (load (s8) from %fixed-stack.1, align 4)
+    %3:gr32 = MOV32rm %fixed-stack.3, 1, $noreg, 0, $noreg :: (load (s32) from %fixed-stack.3)
+    %0:gr32_abcd = MOV32r0 implicit-def dead $eflags
+    TEST32rr %3, %3, implicit-def $eflags
+    %0.sub_8bit:gr32_abcd = SETCCr 5, implicit $eflags
+    %11:gr32 = COPY %3
+    %11:gr32 = SAR32ri %11, 1, implicit-def dead $eflags
+    %4:gr32 = MOV32rm %fixed-stack.2, 1, $noreg, 0, $noreg :: (load (s32) from %fixed-stack.2)
+    %19:gr32 = MOV32r0 implicit-def dead $eflags
+    JMP_1 %bb.2
+  
+  bb.1:
+    successors: %bb.4(0x30000000), %bb.3(0x50000000)
+  
+    DBG_VALUE %0, $noreg, !6, !DIExpression(), debug-location !10
----------------
bevin-hansson wrote:

LiveDebugVariables doesn't seem to like it when I do that, it asserts.

https://github.com/llvm/llvm-project/pull/109962