llvm/test/CodeGen/X86/dbg-baseptr.ll

; RUN: llc -o - %s | FileCheck %s
; RUN: llc -filetype=obj -o - %s | llvm-dwarfdump - | FileCheck %s --check-prefix=DWARF
; This test checks that parameters on the stack pointer are correctly
; referenced by debug info.
target triple = "x86_64--"

@glob = external global i64
@ptr = external global i32*
%struct.s = type { i32, i32, i32, i32, i32 }

; Simple case: no FP, use offset from RSP.

; CHECK-LABEL: f0:
; CHECK-NOT: pushq
; CHECK: movl $42, %eax
; CHECK: retq
define i32 @f0(%struct.s* byval align 8 %input) !dbg !8 {
  call void @llvm.dbg.declare(metadata %struct.s* %input, metadata !4, metadata !17), !dbg !18
  ret i32 42, !dbg !18
}

; DWARF-LABEL: .debug_info contents:

; DWARF-LABEL: DW_TAG_subprogram
; DWARF:   DW_AT_frame_base [DW_FORM_exprloc]      (<0x1> 57 )
;                                                       0x57 -> RSP
; DWARF:   DW_AT_name [DW_FORM_strp]       ( {{.*}}"f0")
; DWARF:   DW_TAG_formal_parameter
; DWARF-NEXT:     DW_AT_location [DW_FORM_exprloc]      (<0x2> 91 08 )
;                                                        DW_OP_fbreg (0x91) 0x08
; DWARF-NEXT:     DW_AT_name [DW_FORM_strp]     ( {{.*}}"input")


; Dynamic alloca forces the use of RBP as the base pointer

; CHECK-LABEL: f1:
; CHECK: pushq %rbp
; CHECK: movl $42, %eax
; CHECK: popq %rbp
; CHECK: retq
define i32 @f1(%struct.s* byval align 8 %input) !dbg !19 {
  %val = load i64, i64* @glob
  ; this alloca should force FP usage.
  %stackspace = alloca i32, i64 %val, align 1
  store i32* %stackspace, i32** @ptr
  call void @llvm.dbg.declare(metadata %struct.s* %input, metadata !20, metadata !17), !dbg !21
  ret i32 42, !dbg !21
}

; DWARF-LABEL: DW_TAG_subprogram
; DWARF:   DW_AT_frame_base [DW_FORM_exprloc]      (<0x1> 56 )
;                                                       0x56 -> RBP
; DWARF:   DW_AT_name [DW_FORM_strp]       ( {{.*}}"f1")
; DWARF:   DW_TAG_formal_parameter
; DWARF-NEXT:     DW_AT_location [DW_FORM_exprloc]      (<0x2> 91 10 )
;                                                        DW_OP_fbreg (0x91) 0x10
; DWARF-NEXT:     DW_AT_name [DW_FORM_strp]     ( {{.*}}"input")

; CHECK-LABEL: f2:
; Just check that we are indeed aligning the stack and setting up a base pointer
; in RBX.
; CHECK: pushq %rbp
; CHECK: movq %rsp, %rbp
; CHECK: pushq %rbx
; CHECK: andq $-64, %rsp
; CHECK: subq $64, %rsp
; CHECK: movq %rsp, %rbx
define i32 @f2(%struct.s* byval align 8 %input) !dbg !22 {
  %val = load i64, i64* @glob
  %stackspace = alloca i32, i64 %val, align 64
  store i32* %stackspace, i32** @ptr
  call void @llvm.dbg.declare(metadata %struct.s* %input, metadata !23, metadata !17), !dbg !24
  ret i32 42, !dbg !24
}

; "input" should still be referred to through RBP.
; DWARF-LABEL: DW_TAG_subprogram
; DWARF:   DW_AT_frame_base [DW_FORM_exprloc]      (<0x1> 56 )
;                                                       0x56 -> RBP
; DWARF:   DW_AT_name [DW_FORM_strp]       ( {{.*}}"f2")
; DWARF:   DW_TAG_formal_parameter
; DWARF-NEXT:     DW_AT_location [DW_FORM_exprloc]      (<0x2> 91 10 )
;                                                        DW_OP_fbreg (0x91) 0x10
; DWARF-NEXT:     DW_AT_name [DW_FORM_strp]     ( {{.*}}"input")

declare void @llvm.dbg.declare(metadata, metadata, metadata)

!llvm.dbg.cu = !{!2}
!llvm.module.flags = !{!0, !1}

!0 = !{i32 2, !"Dwarf Version", i32 4}
!1 = !{i32 2, !"Debug Info Version", i32 3}
!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, emissionKind: FullDebug)
!3 = !DIFile(filename: "dbg-baseptr.ll", directory: "/")
!4 = !DILocalVariable(name: "input", arg: 1, scope: !8, file: !3, line: 5, type: !9)
!5 = !{}

!6 = !DISubroutineType(types: !7)
!7 = !{!10, !9}

!8 = distinct !DISubprogram(name: "f0", file: !3, line: 5, type: !6, isLocal: false, isDefinition: true, unit: !2, variables: !5)

!9 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s", elements: !11)
!10 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
!11 = !{!12, !13, !14, !15, !16}
!12 = !DIDerivedType(tag: DW_TAG_member, name: "a", baseType: !10, size: 32)
!13 = !DIDerivedType(tag: DW_TAG_member, name: "b", baseType: !10, size: 32, offset: 32)
!14 = !DIDerivedType(tag: DW_TAG_member, name: "c", baseType: !10, size: 32, offset: 64)
!15 = !DIDerivedType(tag: DW_TAG_member, name: "d", baseType: !10, size: 32, offset: 96)
!16 = !DIDerivedType(tag: DW_TAG_member, name: "e", baseType: !10, size: 32, offset: 128)

!17 = !DIExpression()
!18 = !DILocation(line: 5, scope: !8)

!19 = distinct !DISubprogram(name: "f1", file: !3, line: 5, type: !6, isLocal: false, isDefinition: true, flags: DIFlagPrototyped, unit: !2, variables: !5)
!20 = !DILocalVariable(name: "input", arg: 1, scope: !19, file: !3, line: 5, type: !9)
!21 = !DILocation(line: 5, scope: !19)
!22 = distinct !DISubprogram(name: "f2", file: !3, line: 5, type: !6, isLocal: false, isDefinition: true, flags: DIFlagPrototyped, unit: !2, variables: !5)
!23 = !DILocalVariable(name: "input", arg: 1, scope: !22, file: !3, line: 5, type: !9)
!24 = !DILocation(line: 5, scope: !22)