dbgcall-site-copy-super-sub.mir 4.85 KB
# RUN: llc -emit-call-site-info -start-after=livedebugvalues -filetype=obj %s -o -| llvm-dwarfdump -| FileCheck %s

# Based on the following reproducer:
#
# #include <stdint.h>
#
# extern uint32_t value32(void);
# extern uint64_t value64(void);
# extern void call32(uint32_t);
# extern void call64(uint64_t);
#
# uint32_t test_sub_reg() {
#   uint32_t local = value32();
#   call64(local);
#   return local;
# }

--- |
  ; ModuleID = 'ext.c'
  source_filename = "ext.c"
  target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"

  ; Function Attrs: minsize nounwind optsize uwtable
  define i32 @test_sub_reg() #0 !dbg !22 {
  entry:
    %call = tail call i32 @value32(), !dbg !29
    call void @llvm.dbg.value(metadata i32 %call, metadata !28, metadata !DIExpression()), !dbg !30
    %conv = zext i32 %call to i64, !dbg !31
    tail call void @call64(i64 %conv), !dbg !31
    ret i32 %call, !dbg !32
  }

  declare !dbg !4 i32 @value32()

  declare !dbg !8 void @call64(i64)

  declare !dbg !12 i64 @value64()

  declare !dbg !15 void @call32(i32)

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

  attributes #0 = { minsize nounwind optsize uwtable }
  attributes #1 = { nounwind readnone speculatable willreturn }

  !llvm.dbg.cu = !{!0}
  !llvm.module.flags = !{!18, !19, !20}
  !llvm.ident = !{!21}

  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, nameTableKind: None)
  !1 = !DIFile(filename: "ext.c", directory: "/")
  !2 = !{}
  !3 = !{!4, !8, !12, !15}
  !4 = !DISubprogram(name: "value32", scope: !1, file: !1, line: 3, type: !5, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
  !5 = !DISubroutineType(types: !6)
  !6 = !{!7}
  !7 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
  !8 = !DISubprogram(name: "call64", scope: !1, file: !1, line: 6, type: !9, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
  !9 = !DISubroutineType(types: !10)
  !10 = !{null, !11}
  !11 = !DIBasicType(name: "long unsigned int", size: 64, encoding: DW_ATE_unsigned)
  !12 = !DISubprogram(name: "value64", scope: !1, file: !1, line: 4, type: !13, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
  !13 = !DISubroutineType(types: !14)
  !14 = !{!11}
  !15 = !DISubprogram(name: "call32", scope: !1, file: !1, line: 5, type: !16, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
  !16 = !DISubroutineType(types: !17)
  !17 = !{null, !7}
  !18 = !{i32 2, !"Dwarf Version", i32 4}
  !19 = !{i32 2, !"Debug Info Version", i32 3}
  !20 = !{i32 1, !"wchar_size", i32 4}
  !21 = !{!"clang version 10.0.0"}
  !22 = distinct !DISubprogram(name: "test_sub_reg", scope: !1, file: !1, line: 8, type: !23, scopeLine: 8, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !27)
  !23 = !DISubroutineType(types: !24)
  !24 = !{!25}
  !25 = !DIDerivedType(tag: DW_TAG_typedef, name: "uint32_t", file: !26, line: 52, baseType: !7)
  !26 = !DIFile(filename: "/usr/include/stdint.h", directory: "")
  !27 = !{!28}
  !28 = !DILocalVariable(name: "local", scope: !22, file: !1, line: 9, type: !25)
  !29 = !DILocation(line: 9, scope: !22)
  !30 = !DILocation(line: 0, scope: !22)
  !31 = !DILocation(line: 10, scope: !22)
  !32 = !DILocation(line: 11, scope: !22)

...
---
name:            test_sub_reg
tracksRegLiveness: true
callSites:
  - { bb: 0, offset: 3 }
  - { bb: 0, offset: 7, fwdArgRegs:
      - { arg: 0, reg: '$rdi' } }
body:             |
  bb.0.entry:
    liveins: $rbx

    frame-setup PUSH64r killed $rbx, implicit-def $rsp, implicit $rsp, debug-location !29
    CFI_INSTRUCTION def_cfa_offset 16
    CFI_INSTRUCTION offset $rbx, -16
    CALL64pcrel32 @value32, csr_64, implicit $rsp, implicit $ssp, implicit-def $rsp, implicit-def $ssp, implicit-def $eax, debug-location !29
    $ebx = MOV32rr $eax, debug-location !29
    DBG_VALUE $ebx, $noreg, !28, !DIExpression(), debug-location !30
    renamable $edi = MOV32rr $ebx, implicit-def $rdi, debug-location !31
    CALL64pcrel32 @call64, csr_64, implicit $rsp, implicit $ssp, implicit $rdi, implicit-def $rsp, implicit-def $ssp, debug-location !31
    $eax = MOV32rr killed $ebx, debug-location !32
    $rbx = frame-destroy POP64r implicit-def $rsp, implicit $rsp, debug-location !32
    CFI_INSTRUCTION def_cfa_offset 8, debug-location !32
    RETQ killed $eax, debug-location !32

...

# Verify that a call site value is emitted for the 64-bit parameter that is
# loaded using the zero-extending MOV32rr.

# CHECK: DW_TAG_GNU_call_site_parameter
# CHECK-NEXT: DW_AT_location (DW_OP_reg5 RDI)
# CHECK-NEXT: DW_AT_GNU_call_site_value (DW_OP_breg3 RBX+0)