dbg-stack-value-range.mir 8.82 KB
# RUN: llc -start-before=livedebugvalues %s -filetype=asm -o -| FileCheck %s
#
# DbgEntityHistoryCalculator should close variable's range at the end of
# the basic block when variable is referenced through non-changing frame
# pointer register. Having BB1 that branches to BB2 and BB3, where
# BB2 falls through to BB3, variable can have different locations at BB1 and BB2.
# Since input locations at BB3 for same variable are different LiveDebugValues
# wont generate DBG_VALUE for BB3. If last variable location at BB2 is
# non-changing register, DbgEntityHistoryCalculator will extend range of
# DBG_VALUE from BB2 to whole BB3 and thus produce incorrect range for
# case when we took branch BB3 from BB1.
#
# Verifies that "local1" stack location is ended at the end of the block (.Ltmp6).
#
# CHECK: .Ltmp4:
# CHECK-NEXT:   #DEBUG_VALUE: foo:local1 <- [DW_OP_constu 4, DW_OP_minus, DW_OP_deref] $rbp
# CHECK:        jmp     .LBB0_2
# CHECK-NEXT: .Ltmp6:
# CHECK: .Lfunc_end0:
#
# CHECK: .Ldebug_loc2:
# CHECK-NEXT: .quad   .Ltmp1-.Lfunc_begin0
# CHECK-NEXT: .quad   .Ltmp4-.Lfunc_begin0
# CHECK-NEXT: .short  1                       # Loc expr size
# CHECK-NEXT: .byte   94                      # super-register DW_OP_reg14
# CHECK-NEXT: .quad   .Ltmp4-.Lfunc_begin0
# CHECK-NEXT: .quad   .Ltmp6-.Lfunc_begin0
# CHECK-NEXT: .short  2                       # Loc expr size
# CHECK-NEXT: .byte   118                     # DW_OP_breg6
# CHECK-NEXT: .byte   124                     # -4
#
# CHECK: .long   .Ldebug_loc2            # DW_AT_location
# CHECK-NEXT: .long   .Linfo_string7          # DW_AT_name
#
# CHECK: .Linfo_string7:
# CHECK-NEXT: .asciz  "local1"
--- |
  ; ModuleID = 'dbg-stack-value-range.ll'
  source_filename = "dbg-stack-value-range.c"
  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"
  
  ; Function Attrs: nounwind uwtable
  define dso_local i32 @foo(i32 %X) local_unnamed_addr #0 !dbg !7 {
  entry:
    %local1 = alloca i32, align 4
    call void @llvm.dbg.value(metadata i32 %X, metadata !12, metadata !DIExpression()), !dbg !15
    %0 = bitcast i32* %local1 to i8*, !dbg !15
    call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %0), !dbg !15
    call void @llvm.dbg.value(metadata i32 5, metadata !14, metadata !DIExpression()), !dbg !15
    %call = tail call i32 (...) @check(), !dbg !15
    %tobool = icmp eq i32 %call, 0, !dbg !15
    br i1 %tobool, label %if.else, label %if.then, !dbg !15
  
  if.then:                                          ; preds = %entry
    call void @llvm.dbg.value(metadata i32 4, metadata !13, metadata !DIExpression()), !dbg !15
    store i32 4, i32* %local1, align 4, !dbg !15, !tbaa !16
    call void @llvm.dbg.value(metadata i32* %local1, metadata !13, metadata !DIExpression(DW_OP_deref)), !dbg !15
    %call1 = call i32 @init(i32* nonnull %local1), !dbg !15
    call void @llvm.dbg.value(metadata i32 undef, metadata !14, metadata !DIExpression()), !dbg !15
    br label %if.end, !dbg !15
  
  if.else:                                          ; preds = %entry
    call void @llvm.dbg.value(metadata i32 5, metadata !13, metadata !DIExpression()), !dbg !15
    store i32 5, i32* %local1, align 4, !dbg !15, !tbaa !16
    br label %if.end
  
  if.end:                                           ; preds = %if.else, %if.then
    %1 = bitcast i32* %local1 to i8*, !dbg !15
    call void @llvm.dbg.value(metadata i32 undef, metadata !14, metadata !DIExpression()), !dbg !15
    %call2 = call i32 (...) @init2(), !dbg !15
    call void @llvm.dbg.value(metadata i32 undef, metadata !14, metadata !DIExpression()), !dbg !15
    %2 = load i32, i32* %local1, align 4, !dbg !15, !tbaa !16
    call void @llvm.dbg.value(metadata i32 %2, metadata !13, metadata !DIExpression()), !dbg !15
    call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %1), !dbg !15
    ret i32 %2, !dbg !15
  }
  
  ; Function Attrs: argmemonly nounwind
  declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture)
  
  declare dso_local i32 @check(...) local_unnamed_addr
  
  declare dso_local i32 @init(i32*) local_unnamed_addr
  
  declare dso_local i32 @init2(...) 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)
  
  ; Function Attrs: nounwind
  declare void @llvm.stackprotector(i8*, i8**)

  attributes #0 = { nounwind uwtable "frame-pointer"="non-leaf" }
  
  !llvm.dbg.cu = !{!0}
  !llvm.module.flags = !{!3, !4, !5}
  !llvm.ident = !{!6}
  
  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
  !1 = !DIFile(filename: "dbg-stack-value-range.c", directory: "/")
  !2 = !{}
  !3 = !{i32 2, !"Dwarf Version", i32 4}
  !4 = !{i32 2, !"Debug Info Version", i32 3}
  !5 = !{i32 1, !"wchar_size", i32 4}
  !6 = !{!"clang version 9.0.0"}
  !7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 11, type: !8, scopeLine: 11, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !11)
  !8 = !DISubroutineType(types: !9)
  !9 = !{!10, !10}
  !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
  !11 = !{!12, !13, !14}
  !12 = !DILocalVariable(name: "X", arg: 1, scope: !7, file: !1, line: 11, type: !10)
  !13 = !DILocalVariable(name: "local1", scope: !7, file: !1, line: 12, type: !10)
  !14 = !DILocalVariable(name: "local2", scope: !7, file: !1, line: 12, type: !10)
  !15 = !DILocation(line: 11, column: 13, scope: !7)
  !16 = !{!17, !17, i64 0}
  !17 = !{!"int", !18, i64 0}
  !18 = !{!"omnipotent char", !19, i64 0}
  !19 = !{!"Simple C/C++ TBAA"}

...
---
name:            foo
alignment:       16
frameInfo:       
  stackSize:       24
  offsetAdjustment: -24
  maxAlignment:    4
  adjustsStack:    true
  hasCalls:        true
fixedStack:      
  - { id: 0, type: spill-slot, offset: -16, size: 8, alignment: 16, stack-id: default, 
      callee-saved-register: '$r14d', callee-saved-restored: true, debug-info-variable: '', 
      debug-info-expression: '', debug-info-location: '' }
stack:           
  - { id: 0, name: local1, type: default, offset: -20, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
body:             |
  bb.0.entry:
    successors: %bb.3(0x30000000), %bb.1(0x50000000)
  
    DBG_VALUE $edi, $noreg, !12, !DIExpression(), debug-location !15
    frame-setup PUSH64r killed $rbp, implicit-def $rsp, implicit $rsp
    CFI_INSTRUCTION def_cfa_offset 16
    CFI_INSTRUCTION offset $rbp, -16
    $rbp = frame-setup MOV64rr $rsp
    CFI_INSTRUCTION def_cfa_register $rbp
    $rsp = frame-setup SUB64ri8 $rsp, 16, implicit-def dead $eflags
    DBG_VALUE 5, $noreg, !14, !DIExpression(), debug-location !15
    $r14d = MOV32ri 4, implicit-def $r14
    DBG_VALUE $r14d, $noreg, !13, !DIExpression(), debug-location !15
    dead $eax = XOR32rr undef $eax, undef $eax, implicit-def dead $eflags, implicit-def $al, debug-location !15
    CALL64pcrel32 @check, csr_64, implicit $rsp, implicit $ssp, implicit $al, implicit-def $rsp, implicit-def $ssp, implicit-def $eax, debug-location !15
    TEST32rr killed renamable $eax, renamable $eax, implicit-def $eflags, debug-location !15
    JCC_1 %bb.3, 4, implicit killed $eflags, debug-location !15
  
  bb.1.if.then:
    successors: %bb.3(0x80000000)
  
    MOV32mr $rbp, 1, $noreg, -4, $noreg, $r14d, debug-location !15 :: (store 4 into %ir.local1, !tbaa !16)
    DBG_VALUE $rbp, $noreg, !13, !DIExpression(DW_OP_constu, 4, DW_OP_minus, DW_OP_deref), debug-location !15
    renamable $rdi = LEA64r $rbp, 1, $noreg, -4, $noreg
    CALL64pcrel32 @init, csr_64, implicit $rsp, implicit $ssp, implicit $rdi, implicit-def $rsp, implicit-def $ssp, implicit-def dead $eax, debug-location !15
    DBG_VALUE $noreg, $noreg, !14, !DIExpression(), debug-location !15
    JMP_1 %bb.3
  
  bb.3.if.end:
    DBG_VALUE $noreg, $noreg, !14, !DIExpression(), debug-location !15
    dead $eax = XOR32rr undef $eax, undef $eax, implicit-def dead $eflags, implicit-def $al, debug-location !15
    CALL64pcrel32 @init2, csr_64, implicit $rsp, implicit $ssp, implicit $al, implicit-def $rsp, implicit-def $ssp, implicit-def dead $eax, debug-location !15
    DBG_VALUE $noreg, $noreg, !14, !DIExpression(), debug-location !15
    renamable $eax = MOV32rm $rbp, 1, $noreg, -4, $noreg, debug-location !15 :: (dereferenceable load 4 from %ir.local1, !tbaa !16)
    $rsp = frame-destroy ADD64ri8 $rsp, 16, implicit-def dead $eflags, debug-location !15
    $rbp = frame-destroy POP64r implicit-def $rsp, implicit $rsp, debug-location !15
    CFI_INSTRUCTION def_cfa $rsp, 8, debug-location !15
    RETQ $eax, debug-location !15

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