[OpenMP][NVPTX] Simplify codegen for orphaned parallel, NFCI.

Worker threads fork off to the compiler generated worker function
directly after entering the kernel function. Hence, there is no
need to check whether the current thread is the master if we are
outside of a parallel region (neither SPMD nor parallel_level > 0).

Differential Revision: https://reviews.llvm.org/D52732

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@343618 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp b/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
index 96cf6c1173b5d78446648432759631329771ad7e..a923232e8173d43931a543789a8ee7ffc0016810 100644 (file)
--- a/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
+++ b/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
@@ -2233,30 +2233,24 @@ void CGOpenMPRuntimeNVPTX::emitNonSPMDParallelCall(
     Work.emplace_back(WFn);
   };
 
-  auto &&LNParallelGen = [this, Loc, &SeqGen, &L0ParallelGen, &CodeGen,
-                          &ThreadIDAddr](CodeGenFunction &CGF,
-                                         PrePostActionTy &Action) {
-    RegionCodeGenTy RCG(CodeGen);
+  auto &&LNParallelGen = [this, Loc, &SeqGen, &L0ParallelGen](
+                             CodeGenFunction &CGF, PrePostActionTy &Action) {
     if (IsInParallelRegion) {
       SeqGen(CGF, Action);
     } else if (IsInTargetMasterThreadRegion) {
       L0ParallelGen(CGF, Action);
-    } else if (getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_NonSPMD) {
-      RCG(CGF);
     } else {
       // Check for master and then parallelism:
       // if (__kmpc_is_spmd_exec_mode() || __kmpc_parallel_level(loc, gtid)) {
-      //  Serialized execution.
-      // } else if (master) {
-      //   Worker call.
+      //   Serialized execution.
       // } else {
-      //   Outlined function call.
+      //   Worker call.
       // }
       CGBuilderTy &Bld = CGF.Builder;
       llvm::BasicBlock *ExitBB = CGF.createBasicBlock(".exit");
       llvm::BasicBlock *SeqBB = CGF.createBasicBlock(".sequential");
       llvm::BasicBlock *ParallelCheckBB = CGF.createBasicBlock(".parcheck");
-      llvm::BasicBlock *MasterCheckBB = CGF.createBasicBlock(".mastercheck");
+      llvm::BasicBlock *MasterBB = CGF.createBasicBlock(".master");
       llvm::Value *IsSPMD = Bld.CreateIsNotNull(CGF.EmitNounwindRuntimeCall(
           createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_is_spmd_exec_mode)));
       Bld.CreateCondBr(IsSPMD, SeqBB, ParallelCheckBB);
@@ -2269,29 +2263,17 @@ void CGOpenMPRuntimeNVPTX::emitNonSPMDParallelCall(
           createNVPTXRuntimeFunction(OMPRTL_NVPTX__kmpc_parallel_level),
           {RTLoc, ThreadID});
       llvm::Value *Res = Bld.CreateIsNotNull(PL);
-      Bld.CreateCondBr(Res, SeqBB, MasterCheckBB);
+      Bld.CreateCondBr(Res, SeqBB, MasterBB);
       CGF.EmitBlock(SeqBB);
       SeqGen(CGF, Action);
       CGF.EmitBranch(ExitBB);
       // There is no need to emit line number for unconditional branch.
       (void)ApplyDebugLocation::CreateEmpty(CGF);
-      CGF.EmitBlock(MasterCheckBB);
-      llvm::BasicBlock *MasterThenBB = CGF.createBasicBlock("master.then");
-      llvm::BasicBlock *ElseBlock = CGF.createBasicBlock("omp_if.else");
-      llvm::Value *IsMaster =
-          Bld.CreateICmpEQ(getNVPTXThreadID(CGF), getMasterThreadID(CGF));
-      Bld.CreateCondBr(IsMaster, MasterThenBB, ElseBlock);
-      CGF.EmitBlock(MasterThenBB);
+      CGF.EmitBlock(MasterBB);
       L0ParallelGen(CGF, Action);
       CGF.EmitBranch(ExitBB);
       // There is no need to emit line number for unconditional branch.
       (void)ApplyDebugLocation::CreateEmpty(CGF);
-      CGF.EmitBlock(ElseBlock);
-      // In the worker need to use the real thread id.
-      ThreadIDAddr = emitThreadIDAddress(CGF, Loc);
-      RCG(CGF);
-      // There is no need to emit line number for unconditional branch.
-      (void)ApplyDebugLocation::CreateEmpty(CGF);
       // Emit the continuation block for code after the if.
       CGF.EmitBlock(ExitBB, /*IsFinished=*/true);
     }

diff --git a/test/OpenMP/nvptx_target_codegen.cpp b/test/OpenMP/nvptx_target_codegen.cpp
index e4049782906ef698026e18cd43033e8a58af4fa6..01f346121a4df16760a7fe5f515a0f8f5fb57c76 100644 (file)
--- a/test/OpenMP/nvptx_target_codegen.cpp
+++ b/test/OpenMP/nvptx_target_codegen.cpp
@@ -557,7 +557,6 @@ int baz(int f, double &a) {
   // CHECK: [[STACK:%.+]] = alloca [[GLOBAL_ST:%.+]],
   // CHECK: [[ZERO_ADDR:%.+]] = alloca i32,
   // CHECK: [[GTID:%.+]] = call i32 @__kmpc_global_thread_num(%struct.ident_t*
-  // CHECK: [[GTID_ADDR:%.+]] = alloca i32,
   // CHECK: store i32 0, i32* [[ZERO_ADDR]]
   // CHECK: [[RES:%.+]] = call i8 @__kmpc_is_spmd_exec_mode()
   // CHECK: [[IS_SPMD:%.+]] = icmp ne i8 [[RES]], 0
@@ -583,9 +582,6 @@ int baz(int f, double &a) {
   // CHECK: call void @__kmpc_end_serialized_parallel(%struct.ident_t* @{{.+}}, i32 [[GTID]])
   // CHECK: br label
 
-  // CHECK: icmp eq i32
-  // CHECK: br i1
-
   // CHECK: call void @__kmpc_kernel_prepare_parallel(i8* bitcast (void (i16, i32)* @{{.+}} to i8*), i16 1)
   // CHECK: call void @__kmpc_begin_sharing_variables(i8*** [[SHARED_PTR:%.+]], i{{64|32}} 2)
   // CHECK: [[SHARED:%.+]] = load i8**, i8*** [[SHARED_PTR]],
@@ -597,10 +593,6 @@ int baz(int f, double &a) {
   // CHECK: call void @__kmpc_end_sharing_variables()
   // CHECK: br label
 
-  // CHECK: store i32 [[GTID]], i32* [[GTID_ADDR]],
-  // CHECK: call void [[OUTLINED]](i32* [[GTID_ADDR]], i32* [[ZERO_ADDR]], i32* [[F_PTR]], double* %{{.+}})
-  // CHECK: br label
-
   // CHECK: [[RES:%.+]] = load i32, i32* [[F_PTR]],
   // CHECK: store i32 [[RES]], i32* [[RET:%.+]],
   // CHECK: br i1 [[IS_SPMD]], label