prolog-epilog-indirection.mir 6.81 KB
# RUN: llc %s -x mir -o - -mtriple=x86_64-unknown-unknown -run-pass=prologepilog | FileCheck %s
#
# Check when the DBG_VALUE on a stack slot below (for var "c") has its  stack
# slot replaced with $rsp and a complex expression, it has DW_OP_stack_value
# added. A direct reference to the stack slot is considered to be the _address_
# of that stack slot, wheras its contents would be an indirect DBG_VALUE.
#
# Check too that for the same DBG_VALUE inst, with an indirect reference to
# the stack slot, we do _not_ get DW_OP_plus_uconst added. This expression
# should remain indirect, referring to the contents of the stack slot.
#
# CHECK:      ![[VAR:[0-9]+]] = !DILocalVariable(name: "c"
# CHECK:      ![[VAR2:[0-9]+]] = !DILocalVariable(name: "asdf"
# CHECK:      ![[VAR3:[0-9]+]] = !DILocalVariable(name: "bees"
#
# CHECK:      LEA64r $rsp
# CHECK-NEXT: DBG_VALUE $rsp, $noreg, ![[VAR]], !DIExpression(DW_OP_plus_uconst, {{[0-9]+}}, DW_OP_stack_value)
# CHECK-NEXT: DBG_VALUE $rsp, $noreg, ![[VAR2]], !DIExpression(DW_OP_plus_uconst, {{[0-9]+}}, DW_OP_stack_value, DW_OP_LLVM_fragment, 1, 2)
# CHECK-NEXT: DBG_VALUE $rsp, $noreg, ![[VAR3]], !DIExpression(DW_OP_plus_uconst, {{[0-9]+}}, DW_OP_LLVM_tag_offset, 0, DW_OP_stack_value)
# CHECK-NEXT: DBG_VALUE 1834104526
# CHECK-NEXT: MOV64mr
# CHECK-NEXT: DBG_VALUE $rsp, 0, ![[VAR]], !DIExpression(DW_OP_plus_uconst, {{[0-9]+}})

--- |
  ; ModuleID = 'out.ll'
  source_filename = "abc.c"
  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"
  
  @b = common dso_local local_unnamed_addr global i32* null, align 8, !dbg !0
  @a = common dso_local local_unnamed_addr global i32 0, align 4, !dbg !6
  
  ; Function Attrs: nounwind uwtable
  define dso_local i32 @main() local_unnamed_addr !dbg !14 {
  entry:
    %l_1081 = alloca i32, align 4
    %0 = bitcast i32* %l_1081 to i8*, !dbg !20
    call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %0), !dbg !20
    call void @llvm.dbg.value(metadata i32 1834104526, metadata !18, metadata !DIExpression()), !dbg !21
    call void @llvm.dbg.value(metadata i32* %l_1081, metadata !19, metadata !DIExpression()), !dbg !21
    store i32* %l_1081, i32** @b, align 8, !dbg !22, !tbaa !23
    store i32 9, i32* @a, align 4, !dbg !27, !tbaa !28
    store i32 9, i32* %l_1081, align 4, !dbg !30, !tbaa !28
    %call = call i32 (...) @optimize_me_not(), !dbg !31
    call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %0), !dbg !32
    ret i32 0, !dbg !32
  }
  
  ; Function Attrs: argmemonly nounwind
  declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture)
  
  declare dso_local i32 @optimize_me_not(...) local_unnamed_addr
  
  ; Function Attrs: argmemonly nounwind
  declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture)
  
  ; Function Attrs: nounwind readnone speculatable
  declare void @llvm.dbg.value(metadata, metadata, metadata)
  
  !llvm.dbg.cu = !{!2}
  !llvm.module.flags = !{!10, !11, !12}
  !llvm.ident = !{!13}
  
  !0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
  !1 = distinct !DIGlobalVariable(name: "b", scope: !2, file: !3, line: 2, type: !9, isLocal: false, isDefinition: true)
  !2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
  !3 = !DIFile(filename: "abc.c", directory: ".")
  !4 = !{}
  !5 = !{!6, !0}
  !6 = !DIGlobalVariableExpression(var: !7, expr: !DIExpression())
  !7 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !8, isLocal: false, isDefinition: true)
  !8 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
  !9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !8, size: 64)
  !10 = !{i32 2, !"Dwarf Version", i32 4}
  !11 = !{i32 2, !"Debug Info Version", i32 3}
  !12 = !{i32 1, !"wchar_size", i32 4}
  !13 = !{!"clang"}
  !14 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 3, type: !15, scopeLine: 3, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !17)
  !15 = !DISubroutineType(types: !16)
  !16 = !{!8}
  !17 = !{!18, !19, !33, !34}
  !18 = !DILocalVariable(name: "l_1081", scope: !14, file: !3, line: 4, type: !8)
  !19 = !DILocalVariable(name: "c", scope: !14, file: !3, line: 5, type: !9)
  !20 = !DILocation(line: 4, column: 3, scope: !14)
  !21 = !DILocation(line: 0, scope: !14)
  !22 = !DILocation(line: 6, column: 5, scope: !14)
  !23 = !{!24, !24, i64 0}
  !24 = !{!"any pointer", !25, i64 0}
  !25 = !{!"omnipotent char", !26, i64 0}
  !26 = !{!"Simple C/C++ TBAA"}
  !27 = !DILocation(line: 7, column: 10, scope: !14)
  !28 = !{!29, !29, i64 0}
  !29 = !{!"int", !25, i64 0}
  !30 = !DILocation(line: 7, column: 6, scope: !14)
  !31 = !DILocation(line: 8, column: 3, scope: !14)
  !32 = !DILocation(line: 9, column: 1, scope: !14)
  !33 = !DILocalVariable(name: "asdf", scope: !14, file: !3, line: 4, type: !8)
  !34 = !DILocalVariable(name: "bees", scope: !14, file: !3, line: 4, type: !8)

...
---
name:            main
alignment:       16
tracksRegLiveness: true
frameInfo:       
  maxAlignment:    4
  hasCalls:        true
stack:           
  - { id: 0, name: l_1081, type: default, offset: 0, size: 4, alignment: 4, 
      callee-saved-register: '', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
body:             |
  bb.0.entry:
    renamable $rax = LEA64r %stack.0.l_1081, 1, $noreg, 0, $noreg
    DBG_VALUE %stack.0.l_1081, $noreg, !19, !DIExpression(), debug-location !21
    DBG_VALUE %stack.0.l_1081, $noreg, !33, !DIExpression(DW_OP_LLVM_fragment, 1, 2), debug-location !21
    DBG_VALUE %stack.0.l_1081, $noreg, !34, !DIExpression(DW_OP_LLVM_tag_offset, 0), debug-location !21
    DBG_VALUE 1834104526, $noreg, !18, !DIExpression(), debug-location !21
    MOV64mr $rip, 1, $noreg, @b, $noreg, killed renamable $rax, debug-location !22 :: (store 8 into @b, !tbaa !23)
    DBG_VALUE %stack.0.l_1081, 0, !19, !DIExpression(), debug-location !21
    MOV32mi $rip, 1, $noreg, @a, $noreg, 9, debug-location !27 :: (store 4 into @a, !tbaa !28)
    MOV32mi %stack.0.l_1081, 1, $noreg, 0, $noreg, 9, debug-location !30 :: (store 4 into %ir.l_1081, !tbaa !28)
    ADJCALLSTACKDOWN64 0, 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp, debug-location !31
    dead $eax = MOV32r0 implicit-def dead $eflags, implicit-def $al, debug-location !31
    CALL64pcrel32 @optimize_me_not, csr_64, implicit $rsp, implicit $ssp, implicit $al, implicit-def $rsp, implicit-def $ssp, implicit-def dead $eax, debug-location !31
    ADJCALLSTACKUP64 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp, debug-location !31
    $eax = MOV32r0 implicit-def dead $eflags, debug-location !32
    RET 0, $eax, debug-location !32

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