[PATCH] D71475: [WIP][OPENMP] Try to fix linear clause crash by emitting alloca for step

[Chi Chun Chen via Phabricator via cfe-commits]

cchen added a comment.

In D71475#1787914 <https://reviews.llvm.org/D71475#1787914>, @ABataev wrote:

> Here is more proper fix. We don't need to capture just `k` here, instead, we need to capture the whole expression.
>  Linear clause has a little bit different processing rather than all other clauses caused by a non-perfect design. Add codegen tests for all combined constructs that may require capturing of the linear step expression. Probably, some additional work in codegen may be required.
>
>   diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
>   index afe0f1a..cb55ace 100644
>   --- a/clang/lib/Sema/SemaOpenMP.cpp
>   +++ b/clang/lib/Sema/SemaOpenMP.cpp
>   @@ -3830,6 +3830,9 @@ StmtResult Sema::ActOnOpenMPRegionEnd(StmtResult S,
>              MarkDeclarationsReferencedInExpr(E);
>            }
>          }
>   +      if (auto *LC = dyn_cast<OMPLinearClause>(Clause))
>   +        if (Expr *E = LC->getStep())
>   +          MarkDeclarationsReferencedInExpr(E);
>          DSAStack->setForceVarCapturing(/*V=*/false);
>        } else if (CaptureRegions.size() > 1 ||
>                   CaptureRegions.back() != OMPD_unknown) {
>   @@ -11396,12 +11399,87 @@ static OpenMPDirectiveKind getOpenMPCaptureRegionForClause(
>          llvm_unreachable("Unknown OpenMP directive");
>        }
>        break;
>   +  case OMPC_linear:
>   +    switch (DKind) {
>   +    case OMPD_taskloop_simd:
>   +    case OMPD_master_taskloop_simd:
>   +    case OMPD_parallel_master_taskloop_simd:
>   +      CaptureRegion = OMPD_taskloop;
>   +      break;
>   +    case OMPD_target_simd:
>   +      CaptureRegion = OMPD_target;
>   +      break;
>   +    case OMPD_target_teams_distribute_simd:
>   +    case OMPD_teams_distribute_simd:
>   +      CaptureRegion = OMPD_teams;
>   +      break;
>   +    case OMPD_target_parallel_for:
>   +    case OMPD_target_parallel_for_simd:
>   +    case OMPD_target_teams_distribute_parallel_for:
>   +    case OMPD_target_teams_distribute_parallel_for_simd:
>   +    case OMPD_teams_distribute_parallel_for:
>   +    case OMPD_teams_distribute_parallel_for_simd:
>   +    case OMPD_distribute_parallel_for:
>   +    case OMPD_distribute_parallel_for_simd:
>   +    case OMPD_parallel_for:
>   +    case OMPD_parallel_for_simd:
>   +      CaptureRegion = OMPD_parallel;
>   +      break;
>   +    case OMPD_parallel_master_taskloop:
>   +    case OMPD_task:
>   +    case OMPD_taskloop:
>   +    case OMPD_master_taskloop:
>   +    case OMPD_target_update:
>   +    case OMPD_target_enter_data:
>   +    case OMPD_target_exit_data:
>   +    case OMPD_target:
>   +    case OMPD_target_teams:
>   +    case OMPD_target_parallel:
>   +    case OMPD_target_teams_distribute:
>   +    case OMPD_target_data:
>   +    case OMPD_teams:
>   +    case OMPD_teams_distribute:
>   +    case OMPD_cancel:
>   +    case OMPD_parallel:
>   +    case OMPD_parallel_master:
>   +    case OMPD_parallel_sections:
>   +    case OMPD_threadprivate:
>   +    case OMPD_allocate:
>   +    case OMPD_taskyield:
>   +    case OMPD_barrier:
>   +    case OMPD_taskwait:
>   +    case OMPD_cancellation_point:
>   +    case OMPD_flush:
>   +    case OMPD_declare_reduction:
>   +    case OMPD_declare_mapper:
>   +    case OMPD_declare_simd:
>   +    case OMPD_declare_variant:
>   +    case OMPD_declare_target:
>   +    case OMPD_end_declare_target:
>   +    case OMPD_simd:
>   +    case OMPD_for:
>   +    case OMPD_for_simd:
>   +    case OMPD_sections:
>   +    case OMPD_section:
>   +    case OMPD_single:
>   +    case OMPD_master:
>   +    case OMPD_critical:
>   +    case OMPD_taskgroup:
>   +    case OMPD_distribute:
>   +    case OMPD_ordered:
>   +    case OMPD_atomic:
>   +    case OMPD_distribute_simd:
>   +    case OMPD_requires:
>   +      llvm_unreachable("Unexpected OpenMP directive with linear-clause");
>   +    case OMPD_unknown:
>   +      llvm_unreachable("Unknown OpenMP directive");
>   +    }
>   +    break;
>      case OMPC_firstprivate:
>      case OMPC_lastprivate:
>      case OMPC_reduction:
>      case OMPC_task_reduction:
>      case OMPC_in_reduction:
>   -  case OMPC_linear:
>      case OMPC_default:
>      case OMPC_proc_bind:
>      case OMPC_safelen:
>   @@ -14377,6 +14455,16 @@ OMPClause *Sema::ActOnOpenMPLinearClause(
>        if (Val.isInvalid())
>          return nullptr;
>        StepExpr = Val.get();
>   +    OpenMPDirectiveKind DKind = DSAStack->getCurrentDirective();
>   +    OpenMPDirectiveKind CaptureRegion =
>   +        getOpenMPCaptureRegionForClause(DKind, OMPC_linear, LangOpts.OpenMP);
>   +    if (CaptureRegion != OMPD_unknown && !CurContext->isDependentContext()) {
>   +      StepExpr = MakeFullExpr(StepExpr).get();
>   +      llvm::MapVector<const Expr *, DeclRefExpr *> Captures;
>   +      StepExpr = tryBuildCapture(*this, StepExpr, Captures).get();
>   +      for (const auto &Pair : Captures)
>   +        ExprCaptures.push_back(Pair.second->getDecl());
>   +    }
>  
>        // Build var to save the step value.
>        VarDecl *SaveVar =
>  
>


Applying this will make many tests fail on `llvm_unreachable("Unexpected OpenMP directive with linear-clause");`.

Test failed:

  Clang :: OpenMP/distribute_simd_ast_print.cpp
  Clang :: OpenMP/distribute_simd_linear_messages.cpp
  Clang :: OpenMP/for_ast_print.cpp
  Clang :: OpenMP/for_linear_codegen.cpp
  Clang :: OpenMP/for_linear_messages.cpp
  Clang :: OpenMP/for_simd_ast_print.cpp
  Clang :: OpenMP/for_simd_codegen.cpp
  Clang :: OpenMP/for_simd_linear_messages.cpp
  Clang :: OpenMP/for_simd_misc_messages.c
  Clang :: OpenMP/loops_explicit_clauses_codegen.cpp
  Clang :: OpenMP/master_taskloop_simd_linear_messages.cpp
  Clang :: OpenMP/parallel_for_linear_codegen.cpp
  Clang :: OpenMP/parallel_for_linear_messages.cpp
  Clang :: OpenMP/parallel_for_simd_codegen.cpp
  Clang :: OpenMP/parallel_for_simd_linear_messages.cpp
  Clang :: OpenMP/parallel_master_taskloop_simd_linear_messages.cpp
  Clang :: OpenMP/simd_ast_print.cpp
  Clang :: OpenMP/simd_codegen.cpp
  Clang :: OpenMP/simd_linear_messages.cpp
  Clang :: OpenMP/simd_misc_messages.c
  Clang :: OpenMP/target_parallel_for_codegen.cpp
  Clang :: OpenMP/target_parallel_for_linear_messages.cpp
  Clang :: OpenMP/target_parallel_for_simd_codegen.cpp
  Clang :: OpenMP/target_parallel_for_simd_linear_messages.cpp
  Clang :: OpenMP/target_simd_codegen.cpp
  Clang :: OpenMP/target_simd_linear_messages.cpp
  Clang :: OpenMP/target_teams_distribute_parallel_for_simd_codegen.cpp
  Clang :: OpenMP/target_teams_distribute_parallel_for_simd_linear_messages.cpp
  Clang :: OpenMP/target_teams_distribute_simd_linear_messages.cpp
  Clang :: OpenMP/taskloop_simd_linear_messages.cpp


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D71475/new/

https://reviews.llvm.org/D71475