Add pre-commit test for LiveDebugVariables reorder issue

Author: dstenb

llvm/test/DebugInfo/Mips/livedebugvariables-reorder.mir

@@ -0,0 +1,84 @@
+# RUN: llc -emit-call-site-info %s -mtriple=mips -start-before=register-coalescer -stop-after=virtregrewriter -o - | FileCheck %s
+
+# FIXME: LiveDebugVariables should not reorder the stack location DBG_VALUE and
+# the fragmented DBG_VALUEs for aaa, as the latter may represent a stale value.
+# It should also not reorder the DBG_VALUEs for the different variables, as
+# that results in noise in pass before/after diffs.
+
+# CHECK-DAG: ![[aaa:[0-9]+]] = !DILocalVariable(name: "aaa"
+# CHECK-DAG: ![[bbb:[0-9]+]] = !DILocalVariable(name: "bbb"
+# CHECK-DAG: ![[ccc:[0-9]+]] = !DILocalVariable(name: "ccc"
+# CHECK-DAG: ![[ddd:[0-9]+]] = !DILocalVariable(name: "ddd"
+
+# CHECK: DBG_VALUE %stack.0, 0, ![[aaa]], !DIExpression()
+# CHECK-NEXT: DBG_VALUE 444, $noreg, ![[ddd]], !DIExpression()
+# CHECK-NEXT: DBG_VALUE 333, $noreg, ![[ccc]], !DIExpression()
+# CHECK-NEXT: DBG_VALUE 222, $noreg, ![[bbb]], !DIExpression()
+# CHECK-NEXT: DBG_VALUE 1002, $noreg, ![[aaa]], !DIExpression(DW_OP_LLVM_fragment, 16, 16)
+# CHECK-NEXT: DBG_VALUE 1001, $noreg, ![[aaa]], !DIExpression(DW_OP_LLVM_fragment, 0, 16)
+
+--- |
+  target datalayout = "E-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64"
+  target triple = "mips"
+
+  define dso_local i32 @main() local_unnamed_addr #0 !dbg !3 {
+  entry:
+    ret i32 0, !dbg !12
+  }
+
+  declare !dbg !14 dso_local i32 @foo() local_unnamed_addr
+
+  declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+  attributes #0 = { "frame-pointer"="all" }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!2}
+
+  !0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang version 19.0.0git", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+  !1 = !DIFile(filename: "main.c", directory: "/", checksumkind: CSK_MD5, checksum: "9edfcd32ce51b21ab508a4a0755aa78b")
+  !2 = !{i32 2, !"Debug Info Version", i32 3}
+  !3 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 12, type: !4, scopeLine: 12, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !7)
+  !4 = !DISubroutineType(types: !5)
+  !5 = !{!6}
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{!8, !9, !10, !11}
+  !8 = !DILocalVariable(name: "aaa", scope: !3, file: !1, line: 13, type: !6)
+  !9 = !DILocalVariable(name: "bbb", scope: !3, file: !1, line: 13, type: !6)
+  !10 = !DILocalVariable(name: "ccc", scope: !3, file: !1, line: 13, type: !6)
+  !11 = !DILocalVariable(name: "ddd", scope: !3, file: !1, line: 13, type: !6)
+  !12 = !DILocation(line: 13, scope: !3)
+  !13 = !{i64 2147496201}
+  !14 = !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !4, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
+
+...
+---
+name:            main
+alignment:       4
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: gpr32 }
+frameInfo:
+  maxAlignment:    1
+  adjustsStack:    true
+  hasCalls:        true
+callSites:
+  - { bb: 0, offset: 1 }
+machineFunctionInfo: {}
+body:             |
+  bb.0.entry:
+    ADJCALLSTACKDOWN 16, 0, implicit-def dead $sp, implicit $sp, debug-location !12
+    JAL @foo, csr_o32_fpxx, implicit-def dead $ra, implicit-def $sp, implicit-def $v0, debug-location !12
+    ADJCALLSTACKUP 16, 0, implicit-def dead $sp, implicit $sp, debug-location !12
+    %0:gpr32 = COPY killed $v0, debug-location !12
+    DBG_VALUE 1001, $noreg, !8, !DIExpression(DW_OP_LLVM_fragment, 0, 16), debug-location !12
+    DBG_VALUE 1002, $noreg, !8, !DIExpression(DW_OP_LLVM_fragment, 16, 16), debug-location !12
+    DBG_VALUE 222, $noreg, !9, !DIExpression(), debug-location !12
+    DBG_VALUE 333, $noreg, !10, !DIExpression(), debug-location !12
+    DBG_VALUE 444, $noreg, !11, !DIExpression(), debug-location !12
+    DBG_VALUE %0, $noreg, !8, !DIExpression(), debug-location !12
+    INLINEASM &"", 1 /* sideeffect attdialect */, 12 /* clobber */, implicit-def dead early-clobber $v0, 12 /* clobber */, implicit-def dead early-clobber $v1, 12 /* clobber */, implicit-def dead early-clobber $a0, 12 /* clobber */, implicit-def dead early-clobber $a1, 12 /* clobber */, implicit-def dead early-clobber $a2, 12 /* clobber */, implicit-def dead early-clobber $a3, 12 /* clobber */, implicit-def dead early-clobber $t0, 12 /* clobber */, implicit-def dead early-clobber $t1, 12 /* clobber */, implicit-def dead early-clobber $t2, 12 /* clobber */, implicit-def dead early-clobber $t3, 12 /* clobber */, implicit-def dead early-clobber $t4, 12 /* clobber */, implicit-def dead early-clobber $t5, 12 /* clobber */, implicit-def dead early-clobber $t6, 12 /* clobber */, implicit-def dead early-clobber $t7, 12 /* clobber */, implicit-def dead early-clobber $t8, 12 /* clobber */, implicit-def dead early-clobber $t9, 12 /* clobber */, implicit-def dead early-clobber $gp, 12 /* clobber */, implicit-def dead early-clobber $ra, 12 /* clobber */, implicit-def dead early-clobber $s0, 12 /* clobber */, implicit-def dead early-clobber $s1, 12 /* clobber */, implicit-def dead early-clobber $s2, 12 /* clobber */, implicit-def dead early-clobber $s3, 12 /* clobber */, implicit-def dead early-clobber $s4, 12 /* clobber */, implicit-def dead early-clobber $s5, 12 /* clobber */, implicit-def dead early-clobber $s6, 12 /* clobber */, implicit-def dead early-clobber $s7, 12 /* clobber */, implicit-def dead early-clobber $at, !13, debug-location !12
+    $v0 = COPY killed %0, debug-location !12
+    RetRA implicit killed $v0, debug-location !12
+
+...