r349192 - [OPENMP][NVPTX]Improved interwarp copy function.
Alexey Bataev via cfe-commits
cfe-commits at lists.llvm.org
Fri Dec 14 13:00:58 PST 2018
Author: abataev
Date: Fri Dec 14 13:00:58 2018
New Revision: 349192
URL: http://llvm.org/viewvc/llvm-project?rev=349192&view=rev
Log:
[OPENMP][NVPTX]Improved interwarp copy function.
Inlined runtime with the current implementation of the interwarp copy
function leads to the undefined behavior because of the not quite
correct implementation of the barriers. Start using generic
__kmpc_barier function instead of the custom made barriers.
Modified:
cfe/trunk/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
cfe/trunk/test/OpenMP/nvptx_target_parallel_reduction_codegen.cpp
cfe/trunk/test/OpenMP/nvptx_teams_reduction_codegen.cpp
Modified: cfe/trunk/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp?rev=349192&r1=349191&r2=349192&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp Fri Dec 14 13:00:58 2018
@@ -189,13 +189,6 @@ enum MachineConfiguration : unsigned {
SharedMemorySize = 128,
};
-enum NamedBarrier : unsigned {
- /// Synchronize on this barrier #ID using a named barrier primitive.
- /// Only the subset of active threads in a parallel region arrive at the
- /// barrier.
- NB_Parallel = 1,
-};
-
static const ValueDecl *getPrivateItem(const Expr *RefExpr) {
RefExpr = RefExpr->IgnoreParens();
if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(RefExpr)) {
@@ -655,26 +648,9 @@ static void getNVPTXCTABarrier(CodeGenFu
CGF.EmitRuntimeCall(F);
}
-/// Get barrier #ID to synchronize selected (multiple of warp size) threads in
-/// a CTA.
-static void getNVPTXBarrier(CodeGenFunction &CGF, int ID,
- llvm::Value *NumThreads) {
- CGBuilderTy &Bld = CGF.Builder;
- llvm::Value *Args[] = {Bld.getInt32(ID), NumThreads};
- llvm::Function *F = llvm::Intrinsic::getDeclaration(
- &CGF.CGM.getModule(), llvm::Intrinsic::nvvm_barrier);
- F->addFnAttr(llvm::Attribute::Convergent);
- CGF.EmitRuntimeCall(F, Args);
-}
-
/// Synchronize all GPU threads in a block.
static void syncCTAThreads(CodeGenFunction &CGF) { getNVPTXCTABarrier(CGF); }
-/// Synchronize worker threads in a parallel region.
-static void syncParallelThreads(CodeGenFunction &CGF, llvm::Value *NumThreads) {
- return getNVPTXBarrier(CGF, NB_Parallel, NumThreads);
-}
-
/// Get the value of the thread_limit clause in the teams directive.
/// For the 'generic' execution mode, the runtime encodes thread_limit in
/// the launch parameters, always starting thread_limit+warpSize threads per
@@ -3272,14 +3248,10 @@ static llvm::Value *emitInterWarpCopyFun
CGF.EmitBlock(MergeBB);
- Address AddrNumWarpsArg = CGF.GetAddrOfLocalVar(&NumWarpsArg);
- llvm::Value *NumWarpsVal = CGF.EmitLoadOfScalar(
- AddrNumWarpsArg, /*Volatile=*/false, C.IntTy, Loc);
-
- llvm::Value *NumActiveThreads = Bld.CreateNSWMul(
- NumWarpsVal, getNVPTXWarpSize(CGF), "num_active_threads");
- // named_barrier_sync(ParallelBarrierID, num_active_threads)
- syncParallelThreads(CGF, NumActiveThreads);
+ // kmpc_barrier.
+ CGM.getOpenMPRuntime().emitBarrierCall(CGF, Loc, OMPD_unknown,
+ /*EmitChecks=*/false,
+ /*ForceSimpleCall=*/true);
//
// Warp 0 copies reduce element from transfer medium.
@@ -3288,6 +3260,10 @@ static llvm::Value *emitInterWarpCopyFun
llvm::BasicBlock *W0ElseBB = CGF.createBasicBlock("else");
llvm::BasicBlock *W0MergeBB = CGF.createBasicBlock("ifcont");
+ Address AddrNumWarpsArg = CGF.GetAddrOfLocalVar(&NumWarpsArg);
+ llvm::Value *NumWarpsVal = CGF.EmitLoadOfScalar(
+ AddrNumWarpsArg, /*Volatile=*/false, C.IntTy, Loc);
+
// Up to 32 threads in warp 0 are active.
llvm::Value *IsActiveThread =
Bld.CreateICmpULT(ThreadID, NumWarpsVal, "is_active_thread");
@@ -3329,7 +3305,10 @@ static llvm::Value *emitInterWarpCopyFun
// While warp 0 copies values from transfer medium, all other warps must
// wait.
- syncParallelThreads(CGF, NumActiveThreads);
+ // kmpc_barrier.
+ CGM.getOpenMPRuntime().emitBarrierCall(CGF, Loc, OMPD_unknown,
+ /*EmitChecks=*/false,
+ /*ForceSimpleCall=*/true);
if (NumIters > 1) {
Cnt = Bld.CreateNSWAdd(Cnt, llvm::ConstantInt::get(CGM.IntTy, /*V=*/1));
CGF.EmitStoreOfScalar(Cnt, CntAddr, /*Volatile=*/false, C.IntTy);
Modified: cfe/trunk/test/OpenMP/nvptx_target_parallel_reduction_codegen.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/OpenMP/nvptx_target_parallel_reduction_codegen.cpp?rev=349192&r1=349191&r2=349192&view=diff
==============================================================================
--- cfe/trunk/test/OpenMP/nvptx_target_parallel_reduction_codegen.cpp (original)
+++ cfe/trunk/test/OpenMP/nvptx_target_parallel_reduction_codegen.cpp Fri Dec 14 13:00:58 2018
@@ -209,9 +209,8 @@ int bar(int n){
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
- // CHECK: [[WS:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
- // CHECK: [[ACTIVE_THREADS:%.+]] = mul nsw i32 [[ACTIVE_WARPS:%.+]], [[WS]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
+ // CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
@@ -231,7 +230,7 @@ int bar(int n){
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: [[NEXT:%.+]] = add nsw i32 [[CNT]], 1
// CHECK: store i32 [[NEXT]], i32* [[CNT_ADDR]],
// CHECK: br label
@@ -446,9 +445,8 @@ int bar(int n){
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
- // CHECK: [[WS:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
- // CHECK: [[ACTIVE_THREADS:%.+]] = mul nsw i32 [[ACTIVE_WARPS:%.+]], [[WS]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
+ // CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
@@ -467,7 +465,7 @@ int bar(int n){
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: [[IS_WARP_MASTER:%.+]] = icmp eq i32 [[LANEID]], 0
// CHECK: br i1 [[IS_WARP_MASTER]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
@@ -486,9 +484,8 @@ int bar(int n){
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
- // CHECK: [[WS:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
- // CHECK: [[ACTIVE_THREADS:%.+]] = mul nsw i32 [[ACTIVE_WARPS:%.+]], [[WS]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
+ // CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
@@ -507,7 +504,7 @@ int bar(int n){
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: ret
@@ -761,9 +758,8 @@ int bar(int n){
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
- // CHECK: [[WS:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
- // CHECK: [[ACTIVE_THREADS:%.+]] = mul nsw i32 [[ACTIVE_WARPS:%.+]], [[WS]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
+ // CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
@@ -782,7 +778,7 @@ int bar(int n){
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: [[IS_WARP_MASTER:%.+]] = icmp eq i32 [[LANEID]], 0
// CHECK: br i1 [[IS_WARP_MASTER]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
@@ -802,9 +798,8 @@ int bar(int n){
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
- // CHECK: [[WS:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
- // CHECK: [[ACTIVE_THREADS:%.+]] = mul nsw i32 [[ACTIVE_WARPS:%.+]], [[WS]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
+ // CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
@@ -824,7 +819,7 @@ int bar(int n){
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: ret
#endif
Modified: cfe/trunk/test/OpenMP/nvptx_teams_reduction_codegen.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/OpenMP/nvptx_teams_reduction_codegen.cpp?rev=349192&r1=349191&r2=349192&view=diff
==============================================================================
--- cfe/trunk/test/OpenMP/nvptx_teams_reduction_codegen.cpp (original)
+++ cfe/trunk/test/OpenMP/nvptx_teams_reduction_codegen.cpp Fri Dec 14 13:00:58 2018
@@ -412,9 +412,8 @@ int bar(int n){
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
- // CHECK: [[WS:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
- // CHECK: [[ACTIVE_THREADS:%.+]] = mul nsw i32 [[ACTIVE_WARPS:%.+]], [[WS]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
+ // CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
@@ -433,7 +432,7 @@ int bar(int n){
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: [[IS_WARP_MASTER:%.+]] = icmp eq i32 [[LANEID]], 0
// CHECK: br i1 [[IS_WARP_MASTER]], label {{%?}}[[DO_COPY:.+]], label {{%?}}[[COPY_ELSE:.+]]
//
@@ -453,9 +452,8 @@ int bar(int n){
//
// Barrier after copy to shared memory storage medium.
// CHECK: [[COPY_CONT]]
- // CHECK: [[WS:%.+]] = call i32 @llvm.nvvm.read.ptx.sreg.warpsize()
- // CHECK: [[ACTIVE_THREADS:%.+]] = mul nsw i32 [[ACTIVE_WARPS:%.+]], [[WS]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
+ // CHECK: [[ACTIVE_WARPS:%.+]] = load i32, i32*
//
// Read into warp 0.
// CHECK: [[IS_W0_ACTIVE_THREAD:%.+]] = icmp ult i32 [[TID:%.+]], [[ACTIVE_WARPS]]
@@ -475,7 +473,7 @@ int bar(int n){
// CHECK: br label {{%?}}[[READ_CONT]]
//
// CHECK: [[READ_CONT]]
- // CHECK: call void @llvm.nvvm.barrier(i32 1, i32 [[ACTIVE_THREADS]])
+ // CHECK: call void @__kmpc_barrier(%struct.ident_t* @
// CHECK: ret
#endif
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