1 //===-- WebAssemblyTargetTransformInfo.cpp - WebAssembly-specific TTI -----===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 /// 9 /// \file 10 /// This file defines the WebAssembly-specific TargetTransformInfo 11 /// implementation. 12 /// 13 //===----------------------------------------------------------------------===// 14 15 #include "WebAssemblyTargetTransformInfo.h" 16 #include "llvm/CodeGen/CostTable.h" 17 #include "llvm/Support/Debug.h" 18 using namespace llvm; 19 20 #define DEBUG_TYPE "wasmtti" 21 22 TargetTransformInfo::PopcntSupportKind 23 WebAssemblyTTIImpl::getPopcntSupport(unsigned TyWidth) const { 24 assert(isPowerOf2_32(TyWidth) && "Ty width must be power of 2"); 25 return TargetTransformInfo::PSK_FastHardware; 26 } 27 28 unsigned WebAssemblyTTIImpl::getNumberOfRegisters(unsigned ClassID) const { 29 unsigned Result = BaseT::getNumberOfRegisters(ClassID); 30 31 // For SIMD, use at least 16 registers, as a rough guess. 32 bool Vector = (ClassID == 1); 33 if (Vector) 34 Result = std::max(Result, 16u); 35 36 return Result; 37 } 38 39 unsigned WebAssemblyTTIImpl::getRegisterBitWidth(bool Vector) const { 40 if (Vector && getST()->hasSIMD128()) 41 return 128; 42 43 return 64; 44 } 45 46 unsigned WebAssemblyTTIImpl::getArithmeticInstrCost( 47 unsigned Opcode, Type *Ty, TTI::OperandValueKind Opd1Info, 48 TTI::OperandValueKind Opd2Info, TTI::OperandValueProperties Opd1PropInfo, 49 TTI::OperandValueProperties Opd2PropInfo, ArrayRef<const Value *> Args) { 50 51 unsigned Cost = BasicTTIImplBase<WebAssemblyTTIImpl>::getArithmeticInstrCost( 52 Opcode, Ty, Opd1Info, Opd2Info, Opd1PropInfo, Opd2PropInfo); 53 54 if (auto *VTy = dyn_cast<VectorType>(Ty)) { 55 switch (Opcode) { 56 case Instruction::LShr: 57 case Instruction::AShr: 58 case Instruction::Shl: 59 // SIMD128's shifts currently only accept a scalar shift count. For each 60 // element, we'll need to extract, op, insert. The following is a rough 61 // approxmation. 62 if (Opd2Info != TTI::OK_UniformValue && 63 Opd2Info != TTI::OK_UniformConstantValue) 64 Cost = VTy->getNumElements() * 65 (TargetTransformInfo::TCC_Basic + 66 getArithmeticInstrCost(Opcode, VTy->getElementType()) + 67 TargetTransformInfo::TCC_Basic); 68 break; 69 } 70 } 71 return Cost; 72 } 73 74 unsigned WebAssemblyTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val, 75 unsigned Index) { 76 unsigned Cost = BasicTTIImplBase::getVectorInstrCost(Opcode, Val, Index); 77 78 // SIMD128's insert/extract currently only take constant indices. 79 if (Index == -1u) 80 return Cost + 25 * TargetTransformInfo::TCC_Expensive; 81 82 return Cost; 83 } 84