diff options
Diffstat (limited to 'clang/lib/CodeGen/CGStmtOpenMP.cpp')
| -rw-r--r-- | clang/lib/CodeGen/CGStmtOpenMP.cpp | 84 |
1 files changed, 68 insertions, 16 deletions
diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp index 0a82adf9654..e3c4384a4bd 100644 --- a/clang/lib/CodeGen/CGStmtOpenMP.cpp +++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp @@ -490,16 +490,50 @@ void CodeGenFunction::EmitOMPForOuterLoop(OpenMPScheduleClauseKind ScheduleKind, llvm::Value *ST, llvm::Value *IL, llvm::Value *Chunk) { auto &RT = CGM.getOpenMPRuntime(); + + // Dynamic scheduling of the outer loop (dynamic, guided, auto, runtime). + const bool Dynamic = RT.isDynamic(ScheduleKind); + assert(!RT.isStaticNonchunked(ScheduleKind, /* Chunked */ Chunk != nullptr) && "static non-chunked schedule does not need outer loop"); - if (RT.isDynamic(ScheduleKind)) { - ErrorUnsupported(&S, "OpenMP loop with dynamic schedule"); - return; - } // Emit outer loop. // // OpenMP [2.7.1, Loop Construct, Description, table 2-1] + // When schedule(dynamic,chunk_size) is specified, the iterations are + // distributed to threads in the team in chunks as the threads request them. + // Each thread executes a chunk of iterations, then requests another chunk, + // until no chunks remain to be distributed. Each chunk contains chunk_size + // iterations, except for the last chunk to be distributed, which may have + // fewer iterations. When no chunk_size is specified, it defaults to 1. + // + // When schedule(guided,chunk_size) is specified, the iterations are assigned + // to threads in the team in chunks as the executing threads request them. + // Each thread executes a chunk of iterations, then requests another chunk, + // until no chunks remain to be assigned. For a chunk_size of 1, the size of + // each chunk is proportional to the number of unassigned iterations divided + // by the number of threads in the team, decreasing to 1. For a chunk_size + // with value k (greater than 1), the size of each chunk is determined in the + // same way, with the restriction that the chunks do not contain fewer than k + // iterations (except for the last chunk to be assigned, which may have fewer + // than k iterations). + // + // When schedule(auto) is specified, the decision regarding scheduling is + // delegated to the compiler and/or runtime system. The programmer gives the + // implementation the freedom to choose any possible mapping of iterations to + // threads in the team. + // + // When schedule(runtime) is specified, the decision regarding scheduling is + // deferred until run time, and the schedule and chunk size are taken from the + // run-sched-var ICV. If the ICV is set to auto, the schedule is + // implementation defined + // + // while(__kmpc_dispatch_next(&LB, &UB)) { + // idx = LB; + // while (idx <= UB) { BODY; ++idx; } // inner loop + // } + // + // OpenMP [2.7.1, Loop Construct, Description, table 2-1] // When schedule(static, chunk_size) is specified, iterations are divided into // chunks of size chunk_size, and the chunks are assigned to the threads in // the team in a round-robin fashion in the order of the thread number. @@ -510,12 +544,16 @@ void CodeGenFunction::EmitOMPForOuterLoop(OpenMPScheduleClauseKind ScheduleKind, // UB = UB + ST; // } // + const Expr *IVExpr = S.getIterationVariable(); const unsigned IVSize = getContext().getTypeSize(IVExpr->getType()); const bool IVSigned = IVExpr->getType()->hasSignedIntegerRepresentation(); - RT.emitForInit(*this, S.getLocStart(), ScheduleKind, IVSize, IVSigned, IL, LB, - UB, ST, Chunk); + RT.emitForInit( + *this, S.getLocStart(), ScheduleKind, IVSize, IVSigned, IL, LB, + (Dynamic ? EmitAnyExpr(S.getLastIteration()).getScalarVal() : UB), ST, + Chunk); + auto LoopExit = getJumpDestInCurrentScope("omp.dispatch.end"); // Start the loop with a block that tests the condition. @@ -524,12 +562,17 @@ void CodeGenFunction::EmitOMPForOuterLoop(OpenMPScheduleClauseKind ScheduleKind, LoopStack.push(CondBlock); llvm::Value *BoolCondVal = nullptr; - // UB = min(UB, GlobalUB) - EmitIgnoredExpr(S.getEnsureUpperBound()); - // IV = LB - EmitIgnoredExpr(S.getInit()); - // IV < UB - BoolCondVal = EvaluateExprAsBool(S.getCond(false)); + if (!Dynamic) { + // UB = min(UB, GlobalUB) + EmitIgnoredExpr(S.getEnsureUpperBound()); + // IV = LB + EmitIgnoredExpr(S.getInit()); + // IV < UB + BoolCondVal = EvaluateExprAsBool(S.getCond(false)); + } else { + BoolCondVal = RT.emitForNext(*this, S.getLocStart(), IVSize, IVSigned, + IL, LB, UB, ST); + } // If there are any cleanups between here and the loop-exit scope, // create a block to stage a loop exit along. @@ -545,6 +588,11 @@ void CodeGenFunction::EmitOMPForOuterLoop(OpenMPScheduleClauseKind ScheduleKind, } EmitBlock(LoopBody); + // Emit "IV = LB" (in case of static schedule, we have already calculated new + // LB for loop condition and emitted it above). + if (Dynamic) + EmitIgnoredExpr(S.getInit()); + // Create a block for the increment. auto Continue = getJumpDestInCurrentScope("omp.dispatch.inc"); BreakContinueStack.push_back(BreakContinue(LoopExit, Continue)); @@ -557,9 +605,11 @@ void CodeGenFunction::EmitOMPForOuterLoop(OpenMPScheduleClauseKind ScheduleKind, EmitBlock(Continue.getBlock()); BreakContinueStack.pop_back(); - // Emit "LB = LB + Stride", "UB = UB + Stride". - EmitIgnoredExpr(S.getNextLowerBound()); - EmitIgnoredExpr(S.getNextUpperBound()); + if (!Dynamic) { + // Emit "LB = LB + Stride", "UB = UB + Stride". + EmitIgnoredExpr(S.getNextLowerBound()); + EmitIgnoredExpr(S.getNextUpperBound()); + } EmitBranch(CondBlock); LoopStack.pop(); @@ -567,7 +617,9 @@ void CodeGenFunction::EmitOMPForOuterLoop(OpenMPScheduleClauseKind ScheduleKind, EmitBlock(LoopExit.getBlock()); // Tell the runtime we are done. - RT.emitForFinish(*this, S.getLocStart(), ScheduleKind); + // FIXME: Also call fini for ordered loops with dynamic scheduling. + if (!Dynamic) + RT.emitForFinish(*this, S.getLocStart(), ScheduleKind); } /// \brief Emit a helper variable and return corresponding lvalue. |
