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Diffstat (limited to 'tensorflow/compiler/xla/service/gpu/instruction_fusion.cc')
-rw-r--r-- | tensorflow/compiler/xla/service/gpu/instruction_fusion.cc | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/tensorflow/compiler/xla/service/gpu/instruction_fusion.cc b/tensorflow/compiler/xla/service/gpu/instruction_fusion.cc new file mode 100644 index 0000000000..91fd7ae77a --- /dev/null +++ b/tensorflow/compiler/xla/service/gpu/instruction_fusion.cc @@ -0,0 +1,90 @@ +/* Copyright 2017 The TensorFlow Authors. All Rights Reserved. + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +==============================================================================*/ + +#include "tensorflow/compiler/xla/service/gpu/instruction_fusion.h" + +#include "tensorflow/compiler/xla/service/gpu/ir_emission_utils.h" +#include "tensorflow/compiler/xla/service/hlo_opcode.h" +#include "tensorflow/compiler/xla/shape_util.h" + +namespace xla { +namespace gpu { + +namespace { + +bool IsFusile(const HloInstruction& hlo) { + return (hlo.IsElementwise() && hlo.operand_count() > 0) || + hlo.opcode() == HloOpcode::kBroadcast || + hlo.opcode() == HloOpcode::kConcatenate || + hlo.opcode() == HloOpcode::kDynamicSlice || + hlo.opcode() == HloOpcode::kDynamicUpdateSlice || + hlo.opcode() == HloOpcode::kFusion || + hlo.opcode() == HloOpcode::kGetTupleElement || + hlo.opcode() == HloOpcode::kPad || + hlo.opcode() == HloOpcode::kReduce || + hlo.opcode() == HloOpcode::kReduceWindow || + hlo.opcode() == HloOpcode::kReshape || + hlo.opcode() == HloOpcode::kSlice || + hlo.opcode() == HloOpcode::kTranspose; +} + +} // namespace + +bool GpuInstructionFusion::ShouldFuse(HloInstruction* consumer, + int64 operand_index) { + HloInstruction* producer = consumer->mutable_operand(operand_index); + + // Do not fuse to-vector reduction into other consumers. They should be + // unfused or the root of a kInput fusion. + if (IsReductionToVector(*producer)) { + return false; + } + + // We can't fuse library calls, so if a user of such an op could become a + // bitcast, leave it unfused. See `xla::InstructionFusion::ShouldFuse` for + // further rationale. + if (producer->CouldBeBitcast() && + ImplementedAsLibraryCall(*producer->operand(0))) { + return false; + } + + // We may need to know original operand layout to emit input fusion, and so + // far, we merely use the layout of an operand of the fusion node, which means + // we must fuse only elementwise operations. This restriction should be lifted + // later if we need to fuse other operations, e.g. transpose, for performance. + if ((IsReductionToVector(*consumer) || + (HloOpcode::kFusion == consumer->opcode() && + HloInstruction::FusionKind::kInput == consumer->fusion_kind())) && + !producer->IsElementwise()) { + return false; + } + + return IsFusile(*producer) && IsFusile(*consumer) && + InstructionFusion::ShouldFuse(consumer, operand_index); +} + +HloInstruction::FusionKind GpuInstructionFusion::ChooseKind( + const HloInstruction* producer, const HloInstruction* consumer) { + if (IsReductionToVector(*consumer)) { + return HloInstruction::FusionKind::kInput; + } + if (HloOpcode::kFusion == consumer->opcode()) { + return consumer->fusion_kind(); + } + return InstructionFusion::ChooseKind(producer, consumer); +} + +} // namespace gpu +} // namespace xla |