40574fefe9
Make the kind of cost explicit throughout the cost model which, apart from making the cost clear, will allow the generic parts to calculate better costs. It will also allow some backends to approximate and correlate the different costs if they wish. Another benefit is that it will also help simplify the cost model around immediate and intrinsic costs, where we currently have multiple APIs. RFC thread: http://lists.llvm.org/pipermail/llvm-dev/2020-April/141263.html Differential Revision: https://reviews.llvm.org/D79002
86 lines
2.9 KiB
C++
86 lines
2.9 KiB
C++
//===-- WebAssemblyTargetTransformInfo.cpp - WebAssembly-specific TTI -----===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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///
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/// \file
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/// This file defines the WebAssembly-specific TargetTransformInfo
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/// implementation.
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///
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//===----------------------------------------------------------------------===//
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#include "WebAssemblyTargetTransformInfo.h"
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#include "llvm/CodeGen/CostTable.h"
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#include "llvm/Support/Debug.h"
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using namespace llvm;
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#define DEBUG_TYPE "wasmtti"
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TargetTransformInfo::PopcntSupportKind
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WebAssemblyTTIImpl::getPopcntSupport(unsigned TyWidth) const {
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assert(isPowerOf2_32(TyWidth) && "Ty width must be power of 2");
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return TargetTransformInfo::PSK_FastHardware;
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}
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unsigned WebAssemblyTTIImpl::getNumberOfRegisters(unsigned ClassID) const {
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unsigned Result = BaseT::getNumberOfRegisters(ClassID);
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// For SIMD, use at least 16 registers, as a rough guess.
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bool Vector = (ClassID == 1);
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if (Vector)
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Result = std::max(Result, 16u);
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return Result;
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}
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unsigned WebAssemblyTTIImpl::getRegisterBitWidth(bool Vector) const {
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if (Vector && getST()->hasSIMD128())
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return 128;
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return 64;
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}
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unsigned WebAssemblyTTIImpl::getArithmeticInstrCost(
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unsigned Opcode, Type *Ty, TTI::TargetCostKind CostKind,
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TTI::OperandValueKind Opd1Info,
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TTI::OperandValueKind Opd2Info, TTI::OperandValueProperties Opd1PropInfo,
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TTI::OperandValueProperties Opd2PropInfo, ArrayRef<const Value *> Args,
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const Instruction *CxtI) {
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unsigned Cost = BasicTTIImplBase<WebAssemblyTTIImpl>::getArithmeticInstrCost(
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Opcode, Ty, CostKind, Opd1Info, Opd2Info, Opd1PropInfo, Opd2PropInfo);
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if (auto *VTy = dyn_cast<VectorType>(Ty)) {
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switch (Opcode) {
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case Instruction::LShr:
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case Instruction::AShr:
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case Instruction::Shl:
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// SIMD128's shifts currently only accept a scalar shift count. For each
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// element, we'll need to extract, op, insert. The following is a rough
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// approxmation.
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if (Opd2Info != TTI::OK_UniformValue &&
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Opd2Info != TTI::OK_UniformConstantValue)
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Cost = VTy->getNumElements() *
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(TargetTransformInfo::TCC_Basic +
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getArithmeticInstrCost(Opcode, VTy->getElementType(), CostKind) +
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TargetTransformInfo::TCC_Basic);
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break;
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}
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}
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return Cost;
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}
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unsigned WebAssemblyTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val,
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unsigned Index) {
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unsigned Cost = BasicTTIImplBase::getVectorInstrCost(Opcode, Val, Index);
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// SIMD128's insert/extract currently only take constant indices.
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if (Index == -1u)
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return Cost + 25 * TargetTransformInfo::TCC_Expensive;
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return Cost;
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}
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