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

[Matt Arsenault 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:
----------------
arsenm wrote:

Delete registers section. Most of these fields will disappear with simplify-mir 

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