Commit dead2486 authored by Tom Stellard's avatar Tom Stellard
Browse files

Merging r311951 and r312038: 

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r311951 | adrian | 2017-08-28 16:07:43 -0700 (Mon, 28 Aug 2017) | 6 lines

Fix a logic error in DwarfExpression::addMachineReg()

This fixes PR34323 and thus splitting undescribable registers into
smaller, describable sub-registers.

https://bugs.llvm.org/show_bug.cgi?id=34323
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r312038 | joerg | 2017-08-29 14:18:07 -0700 (Tue, 29 Aug 2017) | 2 lines

Simplify test case, so that it works for both trunk and release-5.0.

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llvm-svn: 314567
parent 1c536006

llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp

+3 −4
Original line number Diff line number Diff line
@@ -131,13 +131,12 @@ bool DwarfExpression::addMachineReg(const TargetRegisterInfo &TRI, 


    // Intersection between the bits we already emitted and the bits

    // covered by this subregister.

    SmallBitVector Intersection(RegSize, false);

    Intersection.set(Offset, Offset + Size);

    Intersection ^= Coverage;

    SmallBitVector CurSubReg(RegSize, false);

    CurSubReg.set(Offset, Offset + Size);



    // If this sub-register has a DWARF number and we haven't covered

    // its range, emit a DWARF piece for it.

    if (Reg >= 0 && Intersection.any()) {

    if (Reg >= 0 && CurSubReg.test(Coverage)) {

      // Emit a piece for any gap in the coverage.

      if (Offset > CurPos)

        DwarfRegs.push_back({-1, Offset - CurPos, nullptr});

llvm/test/DebugInfo/Sparc/subreg.ll

0 → 100644
+35 −0
Original line number Diff line number Diff line 
; RUN: llc -filetype=obj -O0 < %s -mtriple sparc64-unknown-linux-gnu | llvm-dwarfdump - | FileCheck %s

; The undescribable 128-bit register should be split into two 64-bit registers.

; CHECK: Location description: 90 48 93 08 90 49 93 08

;                              DW_OP_reg74 DW_OP_piece 8 DW_OP_reg75 DW_OP_piece 8 ...



target datalayout = "E-m:e-i64:64-n32:64-S128"

target triple = "sparc64"



; Function Attrs: nounwind readnone

define void @fn1(fp128 %b) local_unnamed_addr !dbg !7 {

entry:

  tail call void @llvm.dbg.value(metadata fp128 %b, i64 0, metadata !13, metadata !18), !dbg !17

  tail call void @llvm.dbg.value(metadata fp128 0xL00000000000000000000000000000000, i64 0, metadata !13, metadata !19), !dbg !17

  ret void, !dbg !20

}



; Function Attrs: nounwind readnone speculatable

declare void @llvm.dbg.value(metadata, i64, metadata, metadata)



!llvm.dbg.cu = !{!0}

!llvm.module.flags = !{!4}



!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, emissionKind: FullDebug)

!1 = !DIFile(filename: "subreg.c", directory: ".")

!4 = !{i32 2, !"Debug Info Version", i32 3}

!7 = distinct !DISubprogram(name: "fn1", scope: !1, file: !1, line: 1, type: !8, unit: !0)

!8 = !DISubroutineType(types: !9)

!9 = !{null, !10}

!10 = !DIBasicType(name: "long double", size: 128, encoding: DW_ATE_float)

!13 = !DILocalVariable(name: "a", scope: !7, file: !1, line: 1, type: !14)

!14 = !DIBasicType(name: "complex", size: 256, encoding: DW_ATE_complex_float)

!17 = !DILocation(line: 1, column: 48, scope: !7)

!18 = !DIExpression(DW_OP_LLVM_fragment, 0, 128)

!19 = !DIExpression(DW_OP_LLVM_fragment, 128, 128)

!20 = !DILocation(line: 1, column: 55, scope: !7)