[llvm] r223981 - A fix for PR21176.
Romanova, Katya
Katya_Romanova at playstation.sony.com
Wed Dec 10 20:06:38 PST 2014
Hi Paul,
That what my initial triaging showed too.
I was sitting and thinking what should I do now? Ask ppc developlers look at it? Look at it myself? Revert my change?
Katya.
-----Original Message-----
From: Robinson, Paul
Sent: Wednesday, December 10, 2014 8:01 PM
To: Romanova, Katya; llvm-commits at cs.uiuc.edu
Subject: RE: [llvm] r223981 - A fix for PR21176.
By chance, I got a bot failure notification that includes this revision.
clang-ppc64-elf-linux2 is getting a failure because it doesn't have a location list at all; it resolves the variable to DW_AT_const_value (13).
That is, it doesn't think that the value changes over the course of the function. Maybe some ppc optimization is losing track of the variable?
Should be reproducible with llc -mtriple=powerpc64-unknown-linux and the dwarf version naturally is irrelevant.
--paulr
> -----Original Message-----
> From: llvm-commits-bounces at cs.uiuc.edu [mailto:llvm-commits-
> bounces at cs.uiuc.edu] On Behalf Of Ekaterina Romanova
> Sent: Wednesday, December 10, 2014 3:20 PM
> To: llvm-commits at cs.uiuc.edu
> Subject: [llvm] r223981 - A fix for PR21176.
>
> Author: kromanova
> Date: Wed Dec 10 17:19:56 2014
> New Revision: 223981
>
> URL: http://llvm.org/viewvc/llvm-project?rev=223981&view=rev
> Log:
> A fix for PR21176.
>
> DW_OP_const <const> doesn't describe a constant value, but a value at
> a constant address.
> The proper way to describe a constant value is DW_OP_constu <const>,
> DW_OP_stack_value.
>
> Added DW_OP_stack_value to the stack.
>
> -This line, and those below, will be ignored--
>
> M lib/CodeGen/AsmPrinter/DwarfDebug.cpp
> A test/DebugInfo/incorrect-variable-debugloc1.ll
>
> Added:
> llvm/trunk/test/DebugInfo/incorrect-variable-debugloc1.ll
> Modified:
> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>
> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
> URL: http://llvm.org/viewvc/llvm-
> project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=223981&r1
> =223
> 980&r2=223981&view=diff
> ======================================================================
> ====
> ====
> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Wed Dec 10
> +++ 17:19:56
> 2014
> @@ -1722,6 +1722,8 @@ void DwarfDebug::emitDebugLocValue(ByteS
> Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
> Streamer.EmitULEB128(Value.getInt());
> }
> + if (getDwarfVersion() >= 4)
> + Streamer.EmitInt8(dwarf::DW_OP_stack_value,
> + "DW_OP_stack_value");
> } else if (Value.isLocation()) {
> MachineLocation Loc = Value.getLoc();
> DIExpression Expr = Value.getExpression();
>
> Added: llvm/trunk/test/DebugInfo/incorrect-variable-debugloc1.ll
> URL: http://llvm.org/viewvc/llvm-
> project/llvm/trunk/test/DebugInfo/incorrect-variable-
> debugloc1.ll?rev=223981&view=auto
> ======================================================================
> ====
> ====
> --- llvm/trunk/test/DebugInfo/incorrect-variable-debugloc1.ll (added)
> +++ llvm/trunk/test/DebugInfo/incorrect-variable-debugloc1.ll Wed Dec
> +++ 10
> 17:19:56 2014
> @@ -0,0 +1,72 @@
> +; REQUIRES: object-emission
> +; RUN: %llc_dwarf -O2 -dwarf-version 2 -filetype=obj < %s | llvm-
> dwarfdump - | FileCheck %s --check-prefix=DWARF23
> +; RUN: %llc_dwarf -O2 -dwarf-version 3 -filetype=obj < %s | llvm-
> dwarfdump - | FileCheck %s --check-prefix=DWARF23
> +; RUN: %llc_dwarf -O2 -dwarf-version 4 -filetype=obj < %s | llvm-
> dwarfdump - | FileCheck %s --check-prefix=DWARF4
> +
> +; This is a test for PR21176.
> +; DW_OP_const <const> doesn't describe a constant value, but a value
> +at a
> constant address.
> +; The proper way to describe a constant value is DW_OP_constu
> +<const>,
> DW_OP_stack_value.
> +
> +; Generated with clang -S -emit-llvm -g -O2 test.cpp
> +
> +; extern int func();
> +;
> +; int main()
> +; {
> +; volatile int c = 13;
> +; c = func();
> +; return c;
> +; }
> +
> +; DWARF23: Location description: 10 0d {{$}} ; DWARF4: Location
> +description: 10 0d 9f
> +
> +; Function Attrs: uwtable
> +define i32 @main() #0 {
> +entry:
> + %c = alloca i32, align 4
> + tail call void @llvm.dbg.value(metadata !15, i64 0, metadata !10,
> metadata !16), !dbg !17
> + store volatile i32 13, i32* %c, align 4, !dbg !18 %call = tail
> + call i32 @_Z4funcv(), !dbg !19 tail call void
> + @llvm.dbg.value(metadata !{i32 %call}, i64 0, metadata
> !10, metadata !16), !dbg !17
> + store volatile i32 %call, i32* %c, align 4, !dbg !19 tail call
> + void @llvm.dbg.value(metadata !{i32* %c}, i64 0, metadata
> !10, metadata !16), !dbg !17
> + %c.0.c.0. = load volatile i32* %c, align 4, !dbg !20
> + ret i32 %c.0.c.0., !dbg !20
> +}
> +
> +declare i32 @_Z4funcv() #1
> +
> +; Function Attrs: nounwind readnone
> +declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #2
> +
> +attributes #0 = { uwtable "less-precise-fpmad"="false"
> +"no-frame-pointer-
> elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false"
> "stack- protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-
> float"="false" }
> +attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-
> elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false"
> "stack- protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-
> float"="false" }
> +attributes #2 = { nounwind readnone }
> +
> +!llvm.dbg.cu = !{!0}
> +!llvm.module.flags = !{!12, !13}
> +!llvm.ident = !{!14}
> +
> +!0 = metadata !{metadata !"0x11\004\00clang version 3.6.0 (trunk
> 223522)\001\00\000\00\001", metadata !1, metadata !2, metadata !2,
> metadata !3, metadata !2, metadata !2} ; [ DW_TAG_compile_unit ]
> [/home/kromanova/ngh/ToT_latest/llvm/test/DebugInfo/test.cpp]
> [DW_LANG_C_plus_plus]
> +!1 = metadata !{metadata !"test.cpp", metadata
> !"/home/kromanova/ngh/ToT_latest/llvm/test/DebugInfo"}
> +!2 = metadata !{}
> +!3 = metadata !{metadata !4}
> +!4 = metadata !{metadata
> !"0x2e\00main\00main\00\003\000\001\000\000\00256\001\004", metadata
> !1, metadata !5, metadata !6, null, i32 ()* @main, null, null,
> metadata !9} ; [ DW_TAG_subprogram ] [line 3] [def] [scope 4] [main]
> +!5 = metadata !{metadata !"0x29", metadata !1} ; [ DW_TAG_file_type ]
> [/home/kromanova/ngh/ToT_latest/llvm/test/DebugInfo/test.cpp]
> +!6 = metadata !{metadata !"0x15\00\000\000\000\000\000\000", null,
> +null,
> null, metadata !7, null, null, null} ; [ DW_TAG_subroutine_type ]
> [line 0, size 0, align 0, offset 0] [from ]
> +!7 = metadata !{metadata !8}
> +!8 = metadata !{metadata !"0x24\00int\000\0032\0032\000\000\005",
> +null,
> null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset
> 0, enc DW_ATE_signed]
> +!9 = metadata !{metadata !10}
> +!10 = metadata !{metadata !"0x100\00c\005\000", metadata !4, metadata
> +!5,
> metadata !11} ; [ DW_TAG_auto_variable ] [c] [line 5]
> +!11 = metadata !{metadata !"0x35\00\000\000\000\000\000", null, null,
> metadata !8} ; [ DW_TAG_volatile_type ] [line 0, size 0, align 0,
> offset 0] [from int]
> +!12 = metadata !{i32 2, metadata !"Dwarf Version", i32 2}
> +!13 = metadata !{i32 2, metadata !"Debug Info Version", i32 2}
> +!14 = metadata !{metadata !"clang version 3.6.0 (trunk 223522)"}
> +!15 = metadata !{i32 13}
> +!16 = metadata !{metadata !"0x102"} ; [ DW_TAG_expression ]
> +!17 = metadata !{i32 5, i32 16, metadata !4, null}
> +!18 = metadata !{i32 5, i32 3, metadata !4, null}
> +!19 = metadata !{i32 6, i32 7, metadata !4, null}
> +!20 = metadata !{i32 7, i32 3, metadata !4, null}
> +
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
More information about the llvm-commits
mailing list