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Se Jong Oh via llvm-dev

2018-Mar-14 19:55 UTC

[llvm-dev] [SelectionDAG] DbgValue nodes aren't transferred

Hi Jonas,

Thanks for taking a look! It makes linear-dbg-value.ll pass for my target by
producing DEBUG_VALUEs correctly. I also tried a simple function with few
operations and confirmed DEBUG_VALUEs which are not produced without
trasferDbgValues in SetPromotedInteger.

Thanks,
Sejong

From: jdevlieghere at apple.com <jdevlieghere at apple.com>
Sent: Wednesday, March 14, 2018 4:07 AM
To: Se Jong Oh <sejooh at microsoft.com>
Cc: Vedant Kumar <vsk at apple.com>; llvm-dev at lists.llvm.org; Adrian
Prantl <aprantl at apple.com>; pidgeot18 at gmail.com
Subject: Re: [llvm-dev] [SelectionDAG] DbgValue nodes aren't transferred

Hi Sejong,

Indeed, I think you are right and we should call transferDbgValues in
SetPromotedInteger.

I couldn’t immediately find a suitable in-tree test to verify this though. Can
you check and let me know whether this works for your target?

Thanks,
Jonas


On Mar 13, 2018, at 7:45 PM, Se Jong Oh <sejooh at
microsoft.com<mailto:sejooh at microsoft.com>> wrote:

Thanks for help! I think that sign extension is not involved here.
PromoteIntegerResult is called since i32 is not a legal type in my target and
the legalizer promotes operations with i32 result type to i64 operations. I
think that SetPromotedInteger seems to be a common place for all promotions like
SetExpandedInteger.

Jonas, I would appreciate it if you can guide me about whether my understanding
is correct or not.

Thanks,
Sejong



From: vsk at apple.com<mailto:vsk at apple.com> <vsk at
apple.com<mailto:vsk at apple.com>>
Sent: Friday, March 9, 2018 3:19 PM
To: Se Jong Oh <sejooh at microsoft.com<mailto:sejooh at
microsoft.com>>
Cc: llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>; Jonas
Devlieghere <jdevlieghere at apple.com<mailto:jdevlieghere at
apple.com>>; Adrian Prantl <aprantl at apple.com<mailto:aprantl at
apple.com>>; pidgeot18 at gmail.com<mailto:pidgeot18 at gmail.com>
Subject: Re: [llvm-dev] [SelectionDAG] DbgValue nodes aren't transferred

+ Adrian, Joshua
+ Jonas, since he contributed the transferDbgValues change in
DAGTypeLegalizer::SetExpandedInteger

On Mar 8, 2018, at 5:44 PM, Se Jong Oh via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:

Hi,

I have a problem that dbg_value nodes are not transferred when integer DAG nodes
are promoted. For example, an i32 add node is promoted to a i64 add node by
DAGTypeLegalizer::PromoteIntegerResult and its dbg_value node is not transferred
to the new node.

t9: i32 = add nsw t5, t8 -->  t31: i64 = add t30, t7   ; the dbg_value node
is not transferred to the new i64 add node.

For expansion, DAGTypeLegalizer::SetExpandedInteger calls transferDbgValues()
but I couldn’t find any place to call trasnferDbgValues() for integer type
promotion in DAGTypeLegalizer ::SetPromotedInteger and other places.

Maybe the right place to do this is within the PromoteIntRes_ helper for sign
extensions?

best,
vedant



I am wondering If I miss anything or the legalization needs to call
transferDbgValues() for this case.

I found this problem because a recently added unittest,
DebugInfo/X86/linear-dbg-value.ll fails for my project, and the x86 and aarch64
backends don’t have this problem since they don’t promote i32 add nodes.

Thanks,
Sejong

_______________________________________________
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llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
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Jonas Devlieghere via llvm-dev

2018-Mar-15 15:42 UTC

head link

[llvm-dev] [SelectionDAG] DbgValue nodes aren't transferred

> On Mar 14, 2018, at 7:55 PM, Se Jong Oh <sejooh at microsoft.com>
wrote:
> 
> Hi Jonas,
>  
> Thanks for taking a look! It makes linear-dbg-value.ll pass for my target
by producing DEBUG_VALUEs correctly. I also tried a simple function with few
operations and confirmed DEBUG_VALUEs which are not produced without
trasferDbgValues in SetPromotedInteger.
That’s great news! Do you plan on creating a patch for this upstream? 
>  
> Thanks,
> Sejong
>  
> From: jdevlieghere at apple.com <jdevlieghere at apple.com> 
> Sent: Wednesday, March 14, 2018 4:07 AM
> To: Se Jong Oh <sejooh at microsoft.com>
> Cc: Vedant Kumar <vsk at apple.com>; llvm-dev at lists.llvm.org;
Adrian Prantl <aprantl at apple.com>; pidgeot18 at gmail.com
> Subject: Re: [llvm-dev] [SelectionDAG] DbgValue nodes aren't
transferred
>  
> Hi Sejong,
>  
> Indeed, I think you are right and we should call transferDbgValues in
SetPromotedInteger.
>  
> I couldn’t immediately find a suitable in-tree test to verify this though.
Can you check and let me know whether this works for your target?
>  
> Thanks,
> Jonas
> 
> 
> On Mar 13, 2018, at 7:45 PM, Se Jong Oh <sejooh at microsoft.com>
wrote:
>  
> Thanks for help! I think that sign extension is not involved here.
PromoteIntegerResult is called since i32 is not a legal type in my target and
the legalizer promotes operations with i32 result type to i64 operations. I
think that SetPromotedInteger seems to be a common place for all promotions like
SetExpandedInteger.
>  
> Jonas, I would appreciate it if you can guide me about whether my
understanding is correct or not.
>  
> Thanks,
> Sejong
>  
>  
>  
> From: vsk at apple.com <vsk at apple.com> 
> Sent: Friday, March 9, 2018 3:19 PM
> To: Se Jong Oh <sejooh at microsoft.com>
> Cc: llvm-dev at lists.llvm.org; Jonas Devlieghere <jdevlieghere at
apple.com>; Adrian Prantl <aprantl at apple.com>; pidgeot18 at
gmail.com
> Subject: Re: [llvm-dev] [SelectionDAG] DbgValue nodes aren't
transferred
>  
> + Adrian, Joshua
> + Jonas, since he contributed the transferDbgValues change in
DAGTypeLegalizer::SetExpandedInteger
>  
> On Mar 8, 2018, at 5:44 PM, Se Jong Oh via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
>  
> Hi,
>  
> I have a problem that dbg_value nodes are not transferred when integer DAG
nodes are promoted. For example, an i32 add node is promoted to a i64 add node
by DAGTypeLegalizer::PromoteIntegerResult and its dbg_value node is not
transferred to the new node.
>  
> t9: i32 = add nsw t5, t8 à  t31: i64 = add t30, t7   ; the dbg_value node
is not transferred to the new i64 add node.
>  
> For expansion, DAGTypeLegalizer::SetExpandedInteger calls
transferDbgValues() but I couldn’t find any place to call trasnferDbgValues()
for integer type promotion in DAGTypeLegalizer ::SetPromotedInteger and other
places.
>  
> Maybe the right place to do this is within the PromoteIntRes_ helper for
sign extensions?
>  
> best,
> vedant
> 
> 
> 
> I am wondering If I miss anything or the legalization needs to call
transferDbgValues() for this case.
>  
> I found this problem because a recently added unittest,
DebugInfo/X86/linear-dbg-value.ll fails for my project, and the x86 and aarch64
backends don’t have this problem since they don’t promote i32 add nodes.
>  
> Thanks,
> Sejong
>  
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

Se Jong Oh via llvm-dev

2018-Apr-30 20:49 UTC

head link

[llvm-dev] [SelectionDAG] DbgValue nodes aren't transferred

Hi Jonas,

I have another case that DBG_VALUE is not produced. I would appreciate it if you
could take a quick look at the testcase below.


test code:

llc -mtriple=aarch64 -stop-after=livedebugvalues -o - test.ll

; Function Attrs: nounwind ssp uwtable
define void @f() #0 !dbg !4 {
entry:
  tail call void @h(i16 0) #2, !dbg !14
  %call = tail call i16 (...) @g() #2, !dbg !15
  tail call void @llvm.dbg.value(metadata i16 %call, metadata !8, metadata !16),
!dbg !17
  tail call void @h(i16 %call) #2, !dbg !18
  ret void, !dbg !19
}

For the second call, the AArch64 ISel lowering produces a 32-bit CopyFromReg
from w0.

  t18: ch,glue = AArch64ISD::CALL t15, TargetGlobalAddress:i64<i16 (...)*
@g> 0, RegisterMask:Untyped, test.c:5:11
  t19: ch,glue = callseq_end t18, TargetConstant:i64<0>,
TargetConstant:i64<0>, t18:1, test.c:5:11
  t20: i32,ch,glue = CopyFromReg t19, Register:i32 $w0, t19:1, test.c:5:11

Then, TargetLowering::LowerCallTo adds a truncate node since the function return
type is i16.

t21: i16 = truncate t20, test.c:5:11

When lowering the dbg.value intrinsic, a SDDbgValue node is attached to the
truncate since it is the final result of the call.

Lowering the third call constructs any_extend(t21) for the 32-bit register type
but optimizes out the truncate node by the following code, and it seems that the
DbgValue node on the truncate is also lost.

SelectionDAG::getNode(...)
...
    // (ext (trunx x)) -> x
    if (OpOpcode == ISD::TRUNCATE) {
      SDValue OpOp = Operand.getOperand(0);
      if (OpOp.getValueType() == VT)
        return OpOp;
    }

I am wondering if we can just transfer the dbg node here or we can have a better
solution.


The entire test file is here:

; ModuleID = 'test.ll'
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx"

; Function Attrs: nounwind ssp uwtable
define void @f() #0 !dbg !4 {
entry:
  tail call void @h(i16 0) #2, !dbg !14
  %call = tail call i16 (...) @g() #2, !dbg !15
  tail call void @llvm.dbg.value(metadata i16 %call, metadata !8, metadata !16),
!dbg !17
  tail call void @h(i16 %call) #2, !dbg !18
  ret void, !dbg !19
}

declare void @h(i16)

declare i16 @g(...)

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

attributes #0 = { nounwind ssp uwtable
"no-frame-pointer-elim"="true" }
attributes #1 = { nounwind readnone }
attributes #2 = { nounwind }

!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!10, !11, !12}
!llvm.ident = !{!13}

!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer:
"clang version 3.9.0 ", isOptimized: true, runtimeVersion: 0,
emissionKind: FullDebug, enums: !2)
!1 = !DIFile(filename: "test.c", directory:
"/Volumes/Data/llvm")
!2 = !{}
!4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 3,
type: !5, isLocal: false, isDefinition: true, scopeLine: 3, isOptimized: true,
unit: !0, variables: !7)
!5 = !DISubroutineType(types: !6)
!6 = !{null}
!7 = !{!8}
!8 = !DILocalVariable(name: "a", scope: !4, file: !1, line: 5, type:
!9)
!9 = !DIBasicType(name: "int", size: 32, align: 32, encoding:
DW_ATE_signed)
!10 = !{i32 2, !"Dwarf Version", i32 2}
!11 = !{i32 2, !"Debug Info Version", i32 3}
!12 = !{i32 1, !"PIC Level", i32 2}
!13 = !{!"clang version 3.9.0 "}
!14 = !DILocation(line: 4, column: 3, scope: !4)
!15 = !DILocation(line: 5, column: 11, scope: !4)
!16 = !DIExpression()
!17 = !DILocation(line: 5, column: 7, scope: !4)
!18 = !DILocation(line: 6, column: 3, scope: !4)
!19 = !DILocation(line: 7, column: 1, scope: !4)


Thanks,
Sejong

-----Original Message-----
From: jdevlieghere at apple.com <jdevlieghere at apple.com> 
Sent: Thursday, March 15, 2018 8:43 AM
To: Se Jong Oh <sejooh at microsoft.com>
Cc: Vedant Kumar <vsk at apple.com>; llvm-dev at lists.llvm.org; Adrian
Prantl <aprantl at apple.com>; pidgeot18 at gmail.com
Subject: Re: [llvm-dev] [SelectionDAG] DbgValue nodes aren't transferred


> On Mar 14, 2018, at 7:55 PM, Se Jong Oh <sejooh at microsoft.com>
wrote:
> 
> Hi Jonas,
>  
> Thanks for taking a look! It makes linear-dbg-value.ll pass for my target
by producing DEBUG_VALUEs correctly. I also tried a simple function with few
operations and confirmed DEBUG_VALUEs which are not produced without
trasferDbgValues in SetPromotedInteger.
That’s great news! Do you plan on creating a patch for this upstream? 
>  
> Thanks,
> Sejong
>  
> From: jdevlieghere at apple.com <jdevlieghere at apple.com> 
> Sent: Wednesday, March 14, 2018 4:07 AM
> To: Se Jong Oh <sejooh at microsoft.com>
> Cc: Vedant Kumar <vsk at apple.com>; llvm-dev at lists.llvm.org;
Adrian Prantl <aprantl at apple.com>; pidgeot18 at gmail.com
> Subject: Re: [llvm-dev] [SelectionDAG] DbgValue nodes aren't
transferred
>  
> Hi Sejong,
>  
> Indeed, I think you are right and we should call transferDbgValues in
SetPromotedInteger.
>  
> I couldn’t immediately find a suitable in-tree test to verify this though.
Can you check and let me know whether this works for your target?
>  
> Thanks,
> Jonas
> 
> 
> On Mar 13, 2018, at 7:45 PM, Se Jong Oh <sejooh at microsoft.com>
wrote:
>  
> Thanks for help! I think that sign extension is not involved here.
PromoteIntegerResult is called since i32 is not a legal type in my target and
the legalizer promotes operations with i32 result type to i64 operations. I
think that SetPromotedInteger seems to be a common place for all promotions like
SetExpandedInteger.
>  
> Jonas, I would appreciate it if you can guide me about whether my
understanding is correct or not.
>  
> Thanks,
> Sejong
>  
>  
>  
> From: vsk at apple.com <vsk at apple.com> 
> Sent: Friday, March 9, 2018 3:19 PM
> To: Se Jong Oh <sejooh at microsoft.com>
> Cc: llvm-dev at lists.llvm.org; Jonas Devlieghere <jdevlieghere at
apple.com>; Adrian Prantl <aprantl at apple.com>; pidgeot18 at
gmail.com
> Subject: Re: [llvm-dev] [SelectionDAG] DbgValue nodes aren't
transferred
>  
> + Adrian, Joshua
> + Jonas, since he contributed the transferDbgValues change in
DAGTypeLegalizer::SetExpandedInteger
>  
> On Mar 8, 2018, at 5:44 PM, Se Jong Oh via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
>  
> Hi,
>  
> I have a problem that dbg_value nodes are not transferred when integer DAG
nodes are promoted. For example, an i32 add node is promoted to a i64 add node
by DAGTypeLegalizer::PromoteIntegerResult and its dbg_value node is not
transferred to the new node.
>  
> t9: i32 = add nsw t5, t8 à  t31: i64 = add t30, t7   ; the dbg_value node
is not transferred to the new i64 add node.
>  
> For expansion, DAGTypeLegalizer::SetExpandedInteger calls
transferDbgValues() but I couldn’t find any place to call trasnferDbgValues()
for integer type promotion in DAGTypeLegalizer ::SetPromotedInteger and other
places.
>  
> Maybe the right place to do this is within the PromoteIntRes_ helper for
sign extensions?
>  
> best,
> vedant
> 
> 
> 
> I am wondering If I miss anything or the legalization needs to call
transferDbgValues() for this case.
>  
> I found this problem because a recently added unittest,
DebugInfo/X86/linear-dbg-value.ll fails for my project, and the x86 and aarch64
backends don’t have this problem since they don’t promote i32 add nodes.
>  
> Thanks,
> Sejong
>  
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
>
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.llvm.org%2Fcgi-bin%2Fmailman%2Flistinfo%2Fllvm-dev&data=04%7C01%7Csejooh%40microsoft.com%7C1334821c889d440e50ae08d58a8b6a62%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636567253755049370%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwifQ%3D%3D%7C-1&sdata=dmkgOHDLY6YWx1SISIdOg8a%2BC5hpT3mITrZZGwV715E%3D&reserved=0

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