test/DebugInfo/MIR/X86/live-debug-vars-unused-arg-debugonly.mir

# RUN: llc -O1 -start-before=greedy -stop-after=virtregrewriter -o /dev/null %s -debug-only=livedebugvars 2>&1 | FileCheck -check-prefix=CHECKDBG %s

# REQUIRES: asserts

# This test case was generated by using the following c program:
#   extern void foo(int, int);
#
#   int bar[2] = {1, 2};
#
#   int main(int argc, char** argv)
#   {
#     int a0 = bar[0];
#     int a1 = bar[1];
#     foo(a0, a1);
#     return 0;
#   }
#
# It was compiled with -g and -O1, and the mir was dumped before ra greedy.

--- |
  ; ModuleID = 'live-debug-vars-unused-arg.ll'
  source_filename = "live-debug-vars-unused-arg.c"
  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"

  @bar = local_unnamed_addr global [2 x i32] [i32 1, i32 2], align 4, !dbg !0

  ; Function Attrs: nounwind uwtable
  define i32 @main(i32 %argc, i8** nocapture readnone %argv) local_unnamed_addr #0 !dbg !14 {
  entry:
    tail call void @llvm.dbg.value(metadata i32 %argc, metadata !21, metadata !DIExpression()), !dbg !25
    tail call void @llvm.dbg.value(metadata i8** %argv, metadata !22, metadata !DIExpression()), !dbg !26
    %0 = load i32, i32* getelementptr inbounds ([2 x i32], [2 x i32]* @bar, i64 0, i64 0), align 4, !dbg !27, !tbaa !28
    tail call void @llvm.dbg.value(metadata i32 %0, metadata !23, metadata !DIExpression()), !dbg !32
    %1 = load i32, i32* getelementptr inbounds ([2 x i32], [2 x i32]* @bar, i64 0, i64 1), align 4, !dbg !33, !tbaa !28
    tail call void @llvm.dbg.value(metadata i32 %1, metadata !24, metadata !DIExpression()), !dbg !34
    tail call void @foo(i32 %0, i32 %1) #2, !dbg !35
    ret i32 0, !dbg !36
  }

  declare void @foo(i32, i32) local_unnamed_addr

  ; Function Attrs: nounwind readnone speculatable
  declare void @llvm.dbg.value(metadata, metadata, metadata) #1

  ; Function Attrs: nounwind
  declare void @llvm.stackprotector(i8*, i8**) #2

  attributes #0 = { nounwind uwtable }
  attributes #1 = { nounwind readnone speculatable }
  attributes #2 = { nounwind }

  !llvm.dbg.cu = !{!2}
  !llvm.module.flags = !{!10, !11, !12}
  !llvm.ident = !{!13}

  !0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
  !1 = distinct !DIGlobalVariable(name: "bar", scope: !2, file: !3, line: 3, type: !6, isLocal: false, isDefinition: true)
  !2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 6.0.0 (trunk 313866) (llvm/trunk 313875)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5)
  !3 = !DIFile(filename: "live-debug-vars-unused-arg.c", directory: "/repo/uabbpet/master")
  !4 = !{}
  !5 = !{!0}
  !6 = !DICompositeType(tag: DW_TAG_array_type, baseType: !7, size: 64, elements: !8)
  !7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
  !8 = !{!9}
  !9 = !DISubrange(count: 2)
  !10 = !{i32 2, !"Dwarf Version", i32 4}
  !11 = !{i32 2, !"Debug Info Version", i32 3}
  !12 = !{i32 1, !"wchar_size", i32 4}
  !13 = !{!"clang version 6.0.0 (trunk 313866) (llvm/trunk 313875)"}
  !14 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 5, type: !15, isLocal: false, isDefinition: true, scopeLine: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !2, retainedNodes: !20)
  !15 = !DISubroutineType(types: !16)
  !16 = !{!7, !7, !17}
  !17 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !18, size: 64)
  !18 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !19, size: 64)
  !19 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
  !20 = !{!21, !22, !23, !24}
  !21 = !DILocalVariable(name: "argc", arg: 1, scope: !14, file: !3, line: 5, type: !7)
  !22 = !DILocalVariable(name: "argv", arg: 2, scope: !14, file: !3, line: 5, type: !17)
  !23 = !DILocalVariable(name: "a0", scope: !14, file: !3, line: 7, type: !7)
  !24 = !DILocalVariable(name: "a1", scope: !14, file: !3, line: 8, type: !7)
  !25 = !DILocation(line: 5, column: 14, scope: !14)
  !26 = !DILocation(line: 5, column: 27, scope: !14)
  !27 = !DILocation(line: 7, column: 12, scope: !14)
  !28 = !{!29, !29, i64 0}
  !29 = !{!"int", !30, i64 0}
  !30 = !{!"omnipotent char", !31, i64 0}
  !31 = !{!"Simple C/C++ TBAA"}
  !32 = !DILocation(line: 7, column: 7, scope: !14)
  !33 = !DILocation(line: 8, column: 12, scope: !14)
  !34 = !DILocation(line: 8, column: 7, scope: !14)
  !35 = !DILocation(line: 9, column: 3, scope: !14)
  !36 = !DILocation(line: 10, column: 3, scope: !14)

...
---
name:            main
alignment:       16
exposesReturnsTwice: false
legalized:       false
regBankSelected: false
selected:        false
tracksRegLiveness: true
registers:
  - { id: 0, class: gr32, preferred-register: '' }
  - { id: 1, class: gr64, preferred-register: '' }
  - { id: 2, class: gr32, preferred-register: '' }
  - { id: 3, class: gr32, preferred-register: '' }
  - { id: 4, class: gr32, preferred-register: '' }
liveins:
frameInfo:
  isFrameAddressTaken: false
  isReturnAddressTaken: false
  hasStackMap:     false
  hasPatchPoint:   false
  stackSize:       0
  offsetAdjustment: 0
  maxAlignment:    0
  adjustsStack:    false
  hasCalls:        true
  stackProtector:  ''
  maxCallFrameSize: 4294967295
  hasOpaqueSPAdjustment: false
  hasVAStart:      false
  hasMustTailInVarArgFunc: false
  savePoint:       ''
  restorePoint:    ''
fixedStack:
stack:
constants:
body:             |
  bb.0.entry:
    DBG_VALUE $edi, _, !21, !DIExpression(), debug-location !25
    DBG_VALUE $rsi, _, !22, !DIExpression(), debug-location !26
    %2 = MOV32rm $rip, 1, _, @bar, _, debug-location !27 :: (dereferenceable load 4 from `i32* getelementptr inbounds ([2 x i32], [2 x i32]* @bar, i64 0, i64 0)`, !tbaa !28)
    DBG_VALUE %2, _, !23, !DIExpression(), debug-location !32
    %3 = MOV32rm $rip, 1, _, @bar + 4, _, debug-location !33 :: (dereferenceable load 4 from `i32* getelementptr inbounds ([2 x i32], [2 x i32]* @bar, i64 0, i64 1)`, !tbaa !28)
    DBG_VALUE %3, _, !24, !DIExpression(), debug-location !34
    ADJCALLSTACKDOWN64 0, 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp, debug-location !35
    $edi = COPY %2, debug-location !35
    $esi = COPY %3, debug-location !35
    CALL64pcrel32 @foo, csr_64, implicit $rsp, implicit $ssp, implicit killed $edi, implicit killed $esi, implicit-def $rsp, debug-location !35
    ADJCALLSTACKUP64 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp, debug-location !35
    $eax = MOV32r0 implicit-def dead $eflags, debug-location !36
    RET 0, killed $eax, debug-location !36

...

# Let's verify that the slot index ranges for the unused variables argc/argv,
# connected to physical regs $edi and $rsi, does not overlap with the ranges
# for %2 and %3. The register allocator is actually allocating the
# virtual registers # to $edi and $esi, so the ranges for argc/argv should
# not cover the whole BB.
#
# CHECKDBG-LABEL: ********** EMITTING LIVE DEBUG VARIABLES **********
# CHECKDBG-NEXT: !"argc,5"        [0B;0e): 0 Loc0=$edi
# CHECKDBG-NEXT:         [0B;0e): 0 %bb.0-160B
# CHECKDBG-NEXT: !"argv,5"        [0B;0e): 0 Loc0=$rsi
# CHECKDBG-NEXT:         [0B;0e): 0 %bb.0-160B
# CHECKDBG-NEXT: !"a0,7"  [16r;64r): 0 Loc0=%2
# CHECKDBG-NEXT:         [16r;64r): 0 %bb.0-160B
# CHECKDBG-NEXT: !"a1,8"  [32r;80r): 0 Loc0=%3
# CHECKDBG-NEXT:         [32r;80r): 0 %bb.0-160B