ad7e6583cd
This allows them to be fused. PiperOrigin-RevId: 327291810 Change-Id: I8e706a6add56e5e9fb4e9262e886f19ee11ac2df
61 lines
2.0 KiB
C++
61 lines
2.0 KiB
C++
/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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==============================================================================*/
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#ifndef TENSORFLOW_COMPILER_XLA_SERVICE_SCATTER_EXPANDER_H_
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#define TENSORFLOW_COMPILER_XLA_SERVICE_SCATTER_EXPANDER_H_
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#include "tensorflow/compiler/xla/service/op_expander_pass.h"
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namespace xla {
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// This pass rewrites scatter operations into (roughly) while loops of
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// dynamic-update-slices.
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//
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// This pass can be used in two ways:
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//
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// - kEliminateAllScatters: For backends that don't support scatter, this pass
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// can convert every scatter into a loop.
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//
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// - kEliminateSimpleScatters: For backends that *do* support scatter, this
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// pass can strength-reduce "simple" scatters -- specifically, scatters that
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// can be represented without a loop -- to dynamic-update-slices.
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//
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// Note that even in kEliminateSimpleScatters mode, this pass may still expand a
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// scatter into a loop (with a trip-count of 1). It's up to other
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// simplification passes to remove the loop.
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class ScatterExpander : public OpExpanderPass {
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public:
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enum Mode {
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kEliminateAllScatters,
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kEliminateSimpleScatters,
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};
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explicit ScatterExpander(Mode m) : mode_(m) {}
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absl::string_view name() const override { return "scatter_expander"; }
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protected:
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bool InstructionMatchesPattern(HloInstruction* inst) override;
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StatusOr<HloInstruction*> ExpandInstruction(HloInstruction* scatter) override;
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private:
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Mode mode_;
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};
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} // namespace xla
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#endif // TENSORFLOW_COMPILER_XLA_SERVICE_SCATTER_EXPANDER_H_
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