[polly] r309490 - Remove Debug metadata from copied instruction to prevent Module verification failure
Sanjay Srivallabh Singapuram via llvm-commits
llvm-commits at lists.llvm.org
Mon Jul 31 05:43:57 PDT 2017
Hello Tobias,
This is interesting ! I'll take a look at it.
My patch was meant only for instructions being copied into GPUModule and
thought that it wouldn't affect IR meant for the CPU.I'll find a way to
remove the debugLoc for IR bound for the GPUModule alone.
Anyways, why are we copying instructions in the first place ? Please move
this to polly-dev if you feel it's more appropriate place.
Thanks,
Sanjay
On Mon, 31 Jul 2017 at 17:15 Tobias Grosser <tobias.grosser at inf.ethz.ch>
wrote:
> I reverted your commit in r309556 to get the buildbots green. We should
> discuss the issue and then try to re-commit as soon as the underlying
> problem has been understood and resolved.
>
> Best,
> Tobias
>
> On Mon, Jul 31, 2017, at 13:42, Tobias Grosser via llvm-commits wrote:
> > Hi Sanjay,
> >
> > since this commit I see build failures on our AOSP buildbot:
> >
> >
> http://lab.llvm.org:8011/builders/aosp-O3-polly-before-vectorizer-unprofitable/builds/205/steps/build-aosp/logs/stdio
> >
> > inlinable function call in a function with debug info must have a !dbg
> > location
> > %p_call = tail call i32 @_Z6_BLENDiii(i32 %blend_type, i32 %p_conv21,
> > i32 %p_conv19)
> >
> > I don't have a test case for this yet, but maybe you can have a quick
> > look!
> >
> > Best,
> > Tobias
> >
> > On Sat, Jul 29, 2017, at 20:03, Singapuram Sanjay Srivallabh via
> > llvm-commits wrote:
> > > Author: singam-sanjay
> > > Date: Sat Jul 29 11:03:49 2017
> > > New Revision: 309490
> > >
> > > URL: http://llvm.org/viewvc/llvm-project?rev=309490&view=rev
> > > Log:
> > > Remove Debug metadata from copied instruction to prevent Module
> > > verification failure
> > >
> > > Summary:
> > > **Remove debug metadata from instruction to be copied to prevent the
> > > source file's debug metadata being copied into GPUModule and eventually
> > > failing Module verification and ASM string codegeneration.**
> > >
> > > When copying the instruction onto the Module meant for the GPU, debug
> > > metadata attached to an instruction causes all related metadata to be
> > > pulled into the Module, including the DICompileUnit, which is not
> listed
> > > in llvm.dbg.cu of the Module. This fails the verification of the
> Module
> > > and generation of the ASM string.
> > >
> > > The only debug metadata of the instruction, the DebugLoc, is unset by
> > > this patch.
> > >
> > > Reviewers: grosser, bollu, Meinersbur
> > >
> > > Reviewed By: grosser, bollu
> > >
> > > Subscribers: pollydev
> > >
> > > Tags: #polly
> > >
> > > Differential Revision: https://reviews.llvm.org/D35630
> > >
> > > Added:
> > > polly/trunk/test/GPGPU/debug-metadata-leak.ll
> > > Modified:
> > > polly/trunk/lib/CodeGen/BlockGenerators.cpp
> > >
> > > Modified: polly/trunk/lib/CodeGen/BlockGenerators.cpp
> > > URL:
> > >
> http://llvm.org/viewvc/llvm-project/polly/trunk/lib/CodeGen/BlockGenerators.cpp?rev=309490&r1=309489&r2=309490&view=diff
> > >
> ==============================================================================
> > > --- polly/trunk/lib/CodeGen/BlockGenerators.cpp (original)
> > > +++ polly/trunk/lib/CodeGen/BlockGenerators.cpp Sat Jul 29 11:03:49
> 2017
> > > @@ -234,6 +234,14 @@ void BlockGenerator::copyInstScalar(Scop
> > > NewInst->replaceUsesOfWith(OldOperand, NewOperand);
> > > }
> > >
> > > + // When copying the instruction onto the Module meant for the GPU,
> > > + // debug metadata attached to an instruction causes all related
> > > + // metadata to be pulled into the Module. This includes the
> > > DICompileUnit,
> > > + // which will not be listed in llvm.dbg.cu of the Module since the
> > > Module
> > > + // doesn't contain one. This fails the verification of the Module
> and
> > > the
> > > + // subsequent generation of the ASM string.
> > > + NewInst->setDebugLoc(llvm::DebugLoc());
> > > +
> > > Builder.Insert(NewInst);
> > > BBMap[Inst] = NewInst;
> > >
> > >
> > > Added: polly/trunk/test/GPGPU/debug-metadata-leak.ll
> > > URL:
> > >
> http://llvm.org/viewvc/llvm-project/polly/trunk/test/GPGPU/debug-metadata-leak.ll?rev=309490&view=auto
> > >
> ==============================================================================
> > > --- polly/trunk/test/GPGPU/debug-metadata-leak.ll (added)
> > > +++ polly/trunk/test/GPGPU/debug-metadata-leak.ll Sat Jul 29 11:03:49
> > > 2017
> > > @@ -0,0 +1,104 @@
> > > +; RUN: opt %loadPolly %s -polly-process-unprofitable
> -polly-codegen-ppcg
> > > -polly-acc-dump-kernel-ir \
> > > +; RUN: | FileCheck --check-prefix=KERNEL-IR %s
> > > +
> > > +; REQUIRES: pollyacc
> > > +
> > > +; KERNEL-IR: define ptx_kernel void @FUNC_vec_add_1_SCOP_0_KERNEL_0(i8
> > > addrspace(1)* %MemRef_arr, i32 %N) #0 {
> > > +
> > > +; The instruction marked <<<LeakyInst>>> is copied into the GPUModule,
> > > +; with changes only to the parameters to access data on the device
> > > instead of
> > > +; the host, i.e., MemRef_arr becomes polly.access.cast.MemRef_arr.
> Since
> > > the
> > > +; instruction is annotated with a DILocation, copying the instruction
> > > also copies
> > > +; the metadata into the GPUModule. This stops codegenerating the
> > > ptx_kernel by
> > > +; failing the verification of the Module in GPUNodeBuilder::finalize,
> > > due to the
> > > +; copied DICompileUnit not being listed in a llvm.dbg.cu which was
> > > neither copied
> > > +; nor created.
> > > +;
> > > +; https://reviews.llvm.org/D35630 removes this debug metadata before
> the
> > > +; instruction is copied to the GPUModule.
> > > +;
> > > +; vec_add_1.c:
> > > +; void vec_add_1(int N, int arr[N]) {
> > > +; int i=0;
> > > +; for( i=0 ; i<N ; i++) arr[i] += 1;
> > > +; }
> > > +;
> > > +source_filename = "vec_add_1.c"
> > > +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
> > > +target triple = "x86_64-unknown-linux-gnu"
> > > +
> > > +define void @vec_add_1(i32 %N, i32* %arr) !dbg !7 {
> > > +entry:
> > > + call void @llvm.dbg.value(metadata i32 %N, i64 0, metadata !13,
> > > metadata !16), !dbg !17
> > > + call void @llvm.dbg.value(metadata i32* %arr, i64 0, metadata !14,
> > > metadata !16), !dbg !18
> > > + call void @llvm.dbg.value(metadata i32 0, i64 0, metadata !15,
> > > metadata !16), !dbg !19
> > > + %tmp = sext i32 %N to i64, !dbg !20
> > > + br label %for.cond, !dbg !20
> > > +
> > > +for.cond: ; preds = %for.inc,
> > > %entry
> > > + %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
> > > + call void @llvm.dbg.value(metadata i32 undef, i64 0, metadata !15,
> > > metadata !16), !dbg !19
> > > + %cmp = icmp slt i64 %indvars.iv, %tmp, !dbg !22
> > > + br i1 %cmp, label %for.body, label %for.end, !dbg !24
> > > +
> > > +for.body: ; preds = %for.cond
> > > + %arrayidx = getelementptr inbounds i32, i32* %arr, i64 %indvars.iv,
> > > !dbg !25
> > > + %tmp1 = load i32, i32* %arrayidx, align 4, !dbg !26, !tbaa !27
> > > + %add = add nsw i32 %tmp1, 1, !dbg !26 ; <<<LeakyInst>>>
> > > + store i32 %add, i32* %arrayidx, align 4, !dbg !26, !tbaa !27
> > > + br label %for.inc, !dbg !25
> > > +
> > > +for.inc: ; preds = %for.body
> > > + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1, !dbg !31
> > > + call void @llvm.dbg.value(metadata !2, i64 0, metadata !15, metadata
> > > !16), !dbg !19
> > > + br label %for.cond, !dbg !32, !llvm.loop !33
> > > +
> > > +for.end: ; preds = %for.cond
> > > + ret void, !dbg !35
> > > +}
> > > +
> > > +declare void @llvm.dbg.declare(metadata, metadata, metadata)
> > > +
> > > +declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
> > > +
> > > +
> > > +!llvm.dbg.cu = !{!0}
> > > +!llvm.module.flags = !{!3, !4, !5}
> > > +!llvm.ident = !{!6}
> > > +
> > > +!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1,
> producer:
> > > "clang version 5.0.0 (http://llvm.org/git/clang.git
> > > 23e042ffe07a923db2dbebf4d2a3692c5a454fee) (
> http://llvm.org/git/llvm.git
> > > 39c5686a1f54884f12120927b1753a750fdb5e02)", isOptimized: true,
> > > runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
> > > +!1 = !DIFile(filename: "vec_add_1.c", directory: "/tmp")
> > > +!2 = !{}
> > > +!3 = !{i32 2, !"Dwarf Version", i32 4}
> > > +!4 = !{i32 2, !"Debug Info Version", i32 3}
> > > +!5 = !{i32 1, !"wchar_size", i32 4}
> > > +!6 = !{!"clang version 5.0.0 (http://llvm.org/git/clang.git
> > > 23e042ffe07a923db2dbebf4d2a3692c5a454fee) (
> http://llvm.org/git/llvm.git
> > > 39c5686a1f54884f12120927b1753a750fdb5e02)"}
> > > +!7 = distinct !DISubprogram(name: "vec_add_1", scope: !1, file: !1,
> > > line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1,
> > > flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !12)
> > > +!8 = !DISubroutineType(types: !9)
> > > +!9 = !{null, !10, !11}
> > > +!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
> > > +!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !10, size:
> 64)
> > > +!12 = !{!13, !14, !15}
> > > +!13 = !DILocalVariable(name: "N", arg: 1, scope: !7, file: !1, line:
> 1,
> > > type: !10)
> > > +!14 = !DILocalVariable(name: "arr", arg: 2, scope: !7, file: !1, line:
> > > 1, type: !11)
> > > +!15 = !DILocalVariable(name: "i", scope: !7, file: !1, line: 2, type:
> > > !10)
> > > +!16 = !DIExpression()
> > > +!17 = !DILocation(line: 1, column: 20, scope: !7)
> > > +!18 = !DILocation(line: 1, column: 27, scope: !7)
> > > +!19 = !DILocation(line: 2, column: 7, scope: !7)
> > > +!20 = !DILocation(line: 3, column: 8, scope: !21)
> > > +!21 = distinct !DILexicalBlock(scope: !7, file: !1, line: 3, column:
> 3)
> > > +!22 = !DILocation(line: 3, column: 15, scope: !23)
> > > +!23 = distinct !DILexicalBlock(scope: !21, file: !1, line: 3, column:
> 3)
> > > +!24 = !DILocation(line: 3, column: 3, scope: !21)
> > > +!25 = !DILocation(line: 3, column: 25, scope: !23)
> > > +!26 = !DILocation(line: 3, column: 32, scope: !23)
> > > +!27 = !{!28, !28, i64 0}
> > > +!28 = !{!"int", !29, i64 0}
> > > +!29 = !{!"omnipotent char", !30, i64 0}
> > > +!30 = !{!"Simple C/C++ TBAA"}
> > > +!31 = !DILocation(line: 3, column: 21, scope: !23)
> > > +!32 = !DILocation(line: 3, column: 3, scope: !23)
> > > +!33 = distinct !{!33, !24, !34}
> > > +!34 = !DILocation(line: 3, column: 35, scope: !21)
> > > +!35 = !DILocation(line: 4, column: 1, scope: !7)
> > >
> > >
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