thr3ads.net - llvm dev - [llvm-dev] What does it mean by a "DICompileUnit missing from llvm.dgs.cu" ?

If this information is useful, please help other people find it:
Share via:

Tobias Grosser via llvm-dev

2017-Mar-12 08:40 UTC

[llvm-dev] What does it mean by a "DICompileUnit missing from llvm.dgs.cu" ? | Where is the error ?

On Sat, Mar 11, 2017, at 07:34 PM, David Blaikie via llvm-dev
wrote:> On Sat, Mar 11, 2017 at 3:10 AM SANJAY SRIVALLABH SINGAPURAM via llvm-dev
> <
> llvm-dev at lists.llvm.org> wrote:
> 
> > Hello,
> >
> > One of my Julia programs failed to execute with the following error,
> > DICompileUnit not listed in llvm.dbg.cu
> > !11 = distinct !DICompileUnit(language: DW_LANG_C89, file: !3,
producer:
> > "julia", isOptimized: true, runtimeVersion: 0,emissionKind:
FullDebug,
> > enums: !12)
> >
> > This was generated by verifyModule(*GPUModule,&(llvm::errs())From
whithin
> > PPCGCodeGeneration.cpp in Polly.
> >
> > From <llvm_src>/test/Verifier/dbg-orphaned-compileunit.ll, I
understand
> > that the debug info, of a compile unit, represented by !11 is missing
from
> > llvm.dbg.cu.
> >
> > What does this mean ? What could have caused this problem and how can
I
> > fix it ?
> >
> 
> At the LLVM level, it means that the CU debug info (DICompileUnit)
wasn't
> listed in the list of all compile units (!llvm.dbg.cu global named
> metadata
> node) when it should be. Whatever produced the IR you are using likely
> has
> a bug and should be fixed to ensure the DICompileUnits created are
> included
> in the !llvm.dbg.cu global named metadata node (check Clang's behavior
> for
> comparison - usually a good reference point)
> 
> This invariant was added a while ago (in LLVM time - I think it was in
> the
> last year or maybe two) by Adrian.
Right. It seems as if Julia is emitting invalid debug symbols. If you
want to point them to this issue, you can probably call 
"verifyModule(*GPUModule))" after their initial IR is generated and
already see the issue. If this is not the case, Polly might make a
mistake when extracting the GPU module and might miss to transfer all
debug information. Can you send me the output of the flag
"-polly-dump-before"?
Can you pass the dumped IR through 'opt' without seeing an error? In
this case, the
IR that enters Polly is still correct, but Polly might mis-transform it.


An alternative fix would be to extract the debug-info stripping
functionality in lib/Transforms/IPO/StripSymbols.cpp into its own
function and call this on our Kernel-IR. It is unlikely that we want to
debug GPU kernels, so we can just remove debug information for now.

Best,
Tobias
> 
> - Dave
> 
> 
> >
> > Thank You,
> > Sanjay
> > _______________________________________________
> > LLVM Developers mailing list
> > llvm-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

SANJAY SRIVALLABH SINGAPURAM via llvm-dev

2017-Mar-13 06:07 UTC

head link

[llvm-dev] What does it mean by a "DICompileUnit missing from llvm.dgs.cu" ? | Where is the error ?

Hello,

I enabled "-polly-dump-before -polly-dump-after" to obtain the IR
before
and after Polly. Have attached kernel_gemm-before.ll (kg_before.ll) and
kernel_gemm-after.ll (kg_after.ll)

observations,

   - Both kg_before.ll and kg_after.ll have,
      - The only DICompileUnit is at !2
      - !llvm.dbg.cu=!{!2}
      - I don't think Julia is generating incorrect debug info .
      - For opt kernel_gemm-before.ll $FLAG -o output.ll
      - All the following FLAGs except "-O3 -polly -polly-target=gpu"
      didn't have a problem with the Module,
         - -O3 -polly -polly-target=cpu
         - -O3
      - The only time verifyModule is called within Polly is at
      kernerlFinalize.
         - This could mean that Polly's generating the wrong debug info,
         which is uncovered only when GPU code's generated.
            - I'm not sure if verifyModule is called indirectly when
            -polly-target=cpu
            - Or, the debug information is corrupted when sending or/and
         receiving information to/from PPCG.
         - For opt output.ll -O3 -polly -polly-target=gpu -o
   output.output.ll, where output.ll generated by opt kg_before.ll -O3 -polly
   -polly-target=cpu,
      - verifyModule is involed thrice, but issues the same error
      - Possibly 3 SCoPs detected ?
      - This increases the possibility that Polly isn't handling the debug
      info properly
      - For opt kernel_gemm-after.ll $ANY_FLAG -o output.ll
      - Cannot invoke an intrinsic other than donothing, patchpoint,
      statepoint, coro_resume or coro_destroy
      -   store void (metadata, i64, metadata, metadata)* @llvm.dbg.value,
      void (metadata, i64, metadata, metadata)** %polly_launch_0_param_7
      - Invalid user of intrinsic instruction!
      -   store void (metadata, i64, metadata, metadata)* @llvm.dbg.value,
      void (metadata, i64, metadata, metadata)** %polly_launch_0_param_7
      - ./llvm_build/bin/opt: kernel_gemm-after.ll: error: input module is
      broken!
      - and output.ll isn't produced.


-Sanjay

Only target=gpu giving me error, but verufyModule is only in the path of
target=gpu.

On Sun, Mar 12, 2017 at 2:10 PM Tobias Grosser <tobias at grosser.es>
wrote:
> On Sat, Mar 11, 2017, at 07:34 PM, David Blaikie via llvm-dev wrote:
> > On Sat, Mar 11, 2017 at 3:10 AM SANJAY SRIVALLABH SINGAPURAM via
llvm-dev
> > <
> > llvm-dev at lists.llvm.org> wrote:
> >
> > > Hello,
> > >
> > > One of my Julia programs failed to execute with the following
error,
> > > DICompileUnit not listed in llvm.dbg.cu
> > > !11 = distinct !DICompileUnit(language: DW_LANG_C89, file: !3,
> producer:
> > > "julia", isOptimized: true, runtimeVersion:
0,emissionKind: FullDebug,
> > > enums: !12)
> > >
> > > This was generated by
verifyModule(*GPUModule,&(llvm::errs())From
> whithin
> > > PPCGCodeGeneration.cpp in Polly.
> > >
> > > From <llvm_src>/test/Verifier/dbg-orphaned-compileunit.ll,
I understand
> > > that the debug info, of a compile unit, represented by !11 is
missing
> from
> > > llvm.dbg.cu.
> > >
> > > What does this mean ? What could have caused this problem and how
can I
> > > fix it ?
> > >
> >
> > At the LLVM level, it means that the CU debug info (DICompileUnit)
wasn't
> > listed in the list of all compile units (!llvm.dbg.cu global named
> > metadata
> > node) when it should be. Whatever produced the IR you are using likely
> > has
> > a bug and should be fixed to ensure the DICompileUnits created are
> > included
> > in the !llvm.dbg.cu global named metadata node (check Clang's
behavior
> > for
> > comparison - usually a good reference point)
> >
> > This invariant was added a while ago (in LLVM time - I think it was in
> > the
> > last year or maybe two) by Adrian.
>
> Right. It seems as if Julia is emitting invalid debug symbols. If you
> want to point them to this issue, you can probably call
> "verifyModule(*GPUModule))" after their initial IR is generated
and
> already see the issue. If this is not the case, Polly might make a
> mistake when extracting the GPU module and might miss to transfer all
> debug information. Can you send me the output of the flag
> "-polly-dump-before"?
> Can you pass the dumped IR through 'opt' without seeing an error?
In
> this case, the
> IR that enters Polly is still correct, but Polly might mis-transform it.
>
>
> An alternative fix would be to extract the debug-info stripping
> functionality in lib/Transforms/IPO/StripSymbols.cpp into its own
> function and call this on our Kernel-IR. It is unlikely that we want to
> debug GPU kernels, so we can just remove debug information for now.
>
> Best,
> Tobias
>
> >
> > - Dave
> >
> >
> > >
> > > Thank You,
> > > Sanjay
> > > _______________________________________________
> > > LLVM Developers mailing list
> > > llvm-dev at lists.llvm.org
> > > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> > >
> > _______________________________________________
> > LLVM Developers mailing list
> > llvm-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20170313/fe8954bd/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: kernel_gemm-before.ll
Type: application/octet-stream
Size: 12296 bytes
Desc: not available
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20170313/fe8954bd/attachment-0002.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: kernel_gemm-after.ll
Type: application/octet-stream
Size: 31051 bytes
Desc: not available
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20170313/fe8954bd/attachment-0003.obj>

Tobias Grosser via llvm-dev

2017-Mar-13 10:56 UTC

head link

[llvm-dev] What does it mean by a "DICompileUnit missing from llvm.dgs.cu" ? | Where is the error ?

On Mon, Mar 13, 2017, at 07:07 AM, SANJAY SRIVALLABH SINGAPURAM via
llvm-dev wrote:> Hello,
> 
> I enabled "-polly-dump-before -polly-dump-after" to obtain the IR
before
> and after Polly. Have attached kernel_gemm-before.ll (kg_before.ll) and
> kernel_gemm-after.ll (kg_after.ll)
Perfect.
 > observations,
> 
>    - Both kg_before.ll and kg_after.ll have,
>       - The only DICompileUnit is at !2
>       - !llvm.dbg.cu=!{!2}
>       - I don't think Julia is generating incorrect debug info .
Neither do I.
>       - For opt kernel_gemm-before.ll $FLAG -o output.ll
>       - All the following FLAGs except "-O3 -polly
-polly-target=gpu"
>       didn't have a problem with the Module,
>          - -O3 -polly -polly-target=cpu
>          - -O3
>
>       - The only time verifyModule is called within Polly is at
>       kernerlFinalize.
>          - This could mean that Polly's generating the wrong debug
info,
>          which is uncovered only when GPU code's generated.
>             - I'm not sure if verifyModule is called indirectly when
>             -polly-target=cpu
>             - Or, the debug information is corrupted when sending or/and
>          receiving information to/from PPCG.
I think we are just generating incorrect code when extracting the GPU
module.
>          - For opt output.ll -O3 -polly -polly-target=gpu -o
>    output.output.ll, where output.ll generated by opt kg_before.ll -O3
>    -polly
>    -polly-target=cpu,
>       - verifyModule is involed thrice, but issues the same error
>       - Possibly 3 SCoPs detected ?
>       - This increases the possibility that Polly isn't handling the
>       debug
>       info properly
>       - For opt kernel_gemm-after.ll $ANY_FLAG -o output.ll
>       - Cannot invoke an intrinsic other than donothing, patchpoint,
>       statepoint, coro_resume or coro_destroy
>       -   store void (metadata, i64, metadata, metadata)*
>       @llvm.dbg.value,
>       void (metadata, i64, metadata, metadata)** %polly_launch_0_param_7
>       - Invalid user of intrinsic instruction!
>       -   store void (metadata, i64, metadata, metadata)*
>       @llvm.dbg.value,
>       void (metadata, i64, metadata, metadata)** %polly_launch_0_param_7
>       - ./llvm_build/bin/opt: kernel_gemm-after.ll: error: input module
>       is
>       broken!
>       - and output.ll isn't produced.
The following patch highlights the first issue:

--- a/lib/CodeGen/PPCGCodeGeneration.cpp
+++ b/lib/CodeGen/PPCGCodeGeneration.cpp
@@ -1163,6 +1163,8 @@ GPUNodeBuilder::createLaunchParameters(ppcg_kernel
*Kernel, Function *F,
   }
 
   for (auto Val : SubtreeValues) {
+    errs() << "Referenced Parameter\n";
+    Val->dump();
     Instruction *Param = new AllocaInst(
         Val->getType(), Launch + "_param_" +
std::to_string(Index),
         EntryBlock->getTerminator());
@@ -1254,8 +1256,8 @@ void GPUNodeBuilder::createKernel(__isl_take
isl_ast_node *KernelStmt) {
   Value *GridDimX, *GridDimY;
   std::tie(GridDimX, GridDimY) = getGridSizes(Kernel);
 
-  createCallLaunchKernel(GPUKernel, GridDimX, GridDimY, BlockDimX,
BlockDimY,
-                         BlockDimZ, Parameters);
+  // createCallLaunchKernel(GPUKernel, GridDimX, GridDimY, BlockDimX,
BlockDimY,
+  //                       BlockDimZ, Parameters);
   createCallFreeKernel(GPUKernel);

opt -polly-codegen-ppcg kernel_gemm-before.ll


opt kernel_gemm-before.ll -polly-codegen-ppcg -polly-acc-dump-kernel-ir
WARNING: You're attempting to print out a bitcode file.
This is inadvisable as it may cause display problems. If
you REALLY want to taste LLVM bitcode first-hand, you
can force output with the `-f' option.

Referenced Parameter

; Function Attrs: nounwind readnone
declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #2

Referenced Parameter
i64 %1
Referenced Parameter
i64 %0
Cannot invoke an intrinsic other than donothing, patchpoint, statepoint,
coro_resume or coro_destroy
  store void (metadata, i64, metadata, metadata)* @llvm.dbg.value, void
  (metadata, i64, metadata, metadata)** %polly_launch_0_param_7
LLVM ERROR: Broken function found, compilation aborted!

We try to pass the llvm.dbg.value function call to the kernel. This does
not work. We should not list @llvm.dbg.value in the Subtree values that
are passed to the kernel.
In fact, we should ignore all debug tree values and not code-generate
them at all.

Best,
Tobias
> 
> 
> -Sanjay
> 
> Only target=gpu giving me error, but verufyModule is only in the path of
> target=gpu.
> 
> On Sun, Mar 12, 2017 at 2:10 PM Tobias Grosser <tobias at grosser.es>
wrote:
> 
> > On Sat, Mar 11, 2017, at 07:34 PM, David Blaikie via llvm-dev wrote:
> > > On Sat, Mar 11, 2017 at 3:10 AM SANJAY SRIVALLABH SINGAPURAM via
llvm-dev
> > > <
> > > llvm-dev at lists.llvm.org> wrote:
> > >
> > > > Hello,
> > > >
> > > > One of my Julia programs failed to execute with the
following error,
> > > > DICompileUnit not listed in llvm.dbg.cu
> > > > !11 = distinct !DICompileUnit(language: DW_LANG_C89, file:
!3,
> > producer:
> > > > "julia", isOptimized: true, runtimeVersion:
0,emissionKind: FullDebug,
> > > > enums: !12)
> > > >
> > > > This was generated by
verifyModule(*GPUModule,&(llvm::errs())From
> > whithin
> > > > PPCGCodeGeneration.cpp in Polly.
> > > >
> > > > From
<llvm_src>/test/Verifier/dbg-orphaned-compileunit.ll, I understand
> > > > that the debug info, of a compile unit, represented by !11
is missing
> > from
> > > > llvm.dbg.cu.
> > > >
> > > > What does this mean ? What could have caused this problem
and how can I
> > > > fix it ?
> > > >
> > >
> > > At the LLVM level, it means that the CU debug info
(DICompileUnit) wasn't
> > > listed in the list of all compile units (!llvm.dbg.cu global
named
> > > metadata
> > > node) when it should be. Whatever produced the IR you are using
likely
> > > has
> > > a bug and should be fixed to ensure the DICompileUnits created
are
> > > included
> > > in the !llvm.dbg.cu global named metadata node (check Clang's
behavior
> > > for
> > > comparison - usually a good reference point)
> > >
> > > This invariant was added a while ago (in LLVM time - I think it
was in
> > > the
> > > last year or maybe two) by Adrian.
> >
> > Right. It seems as if Julia is emitting invalid debug symbols. If you
> > want to point them to this issue, you can probably call
> > "verifyModule(*GPUModule))" after their initial IR is
generated and
> > already see the issue. If this is not the case, Polly might make a
> > mistake when extracting the GPU module and might miss to transfer all
> > debug information. Can you send me the output of the flag
> > "-polly-dump-before"?
> > Can you pass the dumped IR through 'opt' without seeing an
error? In
> > this case, the
> > IR that enters Polly is still correct, but Polly might mis-transform
it.
> >
> >
> > An alternative fix would be to extract the debug-info stripping
> > functionality in lib/Transforms/IPO/StripSymbols.cpp into its own
> > function and call this on our Kernel-IR. It is unlikely that we want
to
> > debug GPU kernels, so we can just remove debug information for now.
> >
> > Best,
> > Tobias
> >
> > >
> > > - Dave
> > >
> > >
> > > >
> > > > Thank You,
> > > > Sanjay
> > > > _______________________________________________
> > > > LLVM Developers mailing list
> > > > llvm-dev at lists.llvm.org
> > > > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> > > >
> > > _______________________________________________
> > > LLVM Developers mailing list
> > > llvm-dev at lists.llvm.org
> > > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> Email had 2 attachments:
> + kernel_gemm-before.ll
>   16k (application/octet-stream)
> + kernel_gemm-after.ll
>   41k (application/octet-stream)

llvm dev - Mar 2017 - What does it mean by a "DICompileUnit missing from llvm.dgs.cu" ? | Where is the error ?

[llvm-dev] What does it mean by a "DICompileUnit missing from llvm.dgs.cu" ? | Where is the error ?

[llvm-dev] What does it mean by a "DICompileUnit missing from llvm.dgs.cu" ? | Where is the error ?

[llvm-dev] What does it mean by a "DICompileUnit missing from llvm.dgs.cu" ? | Where is the error ?