126 lines · cpp
1//===- LoongArchMatInt.cpp - Immediate materialisation ---------*- C++ -*--===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "LoongArchMatInt.h"10#include "MCTargetDesc/LoongArchMCTargetDesc.h"11#include "llvm/Support/MathExtras.h"12 13using namespace llvm;14 15LoongArchMatInt::InstSeq LoongArchMatInt::generateInstSeq(int64_t Val) {16 // Val:17 // | hi32 | lo32 |18 // +-----------+------------------+------------------+-----------+19 // | Highest12 | Higher20 | Hi20 | Lo12 |20 // +-----------+------------------+------------------+-----------+21 // 63 52 51 32 31 12 11 022 //23 const int64_t Highest12 = Val >> 52 & 0xFFF;24 const int64_t Higher20 = Val >> 32 & 0xFFFFF;25 const int64_t Hi20 = Val >> 12 & 0xFFFFF;26 const int64_t Lo12 = Val & 0xFFF;27 InstSeq Insts;28 29 // LU52I_D used for: Bits[63:52] | Bits[51:0].30 if (Highest12 != 0 && SignExtend64<52>(Val) == 0) {31 Insts.push_back(Inst(LoongArch::LU52I_D, SignExtend64<12>(Highest12)));32 return Insts;33 }34 35 // lo3236 if (Hi20 == 0)37 Insts.push_back(Inst(LoongArch::ORI, Lo12));38 else if (SignExtend32<1>(Lo12 >> 11) == SignExtend32<20>(Hi20))39 Insts.push_back(Inst(LoongArch::ADDI_W, SignExtend64<12>(Lo12)));40 else {41 Insts.push_back(Inst(LoongArch::LU12I_W, SignExtend64<20>(Hi20)));42 if (Lo12 != 0)43 Insts.push_back(Inst(LoongArch::ORI, Lo12));44 }45 46 // hi3247 // Higher2048 if (SignExtend32<1>(Hi20 >> 19) != SignExtend32<20>(Higher20))49 Insts.push_back(Inst(LoongArch::LU32I_D, SignExtend64<20>(Higher20)));50 51 // Highest1252 if (SignExtend32<1>(Higher20 >> 19) != SignExtend32<12>(Highest12))53 Insts.push_back(Inst(LoongArch::LU52I_D, SignExtend64<12>(Highest12)));54 55 size_t N = Insts.size();56 if (N < 3)57 return Insts;58 59 // When the number of instruction sequences is greater than 2, we have the60 // opportunity to optimize using the BSTRINS_D instruction. The scenario is as61 // follows:62 //63 // N of Insts = 364 // 1. ORI + LU32I_D + LU52I_D => ORI + BSTRINS_D, TmpVal = ORI65 // 2. ADDI_W + LU32I_D + LU52I_D => ADDI_W + BSTRINS_D, TmpVal = ADDI_W66 // 3. LU12I_W + ORI + LU32I_D => ORI + BSTRINS_D, TmpVal = ORI67 // 4. LU12I_W + LU32I_D + LU52I_D => LU12I_W + BSTRINS_D, TmpVal = LU12I_W68 //69 // N of Insts = 470 // 5. LU12I_W + ORI + LU32I_D + LU52I_D => LU12I_W + ORI + BSTRINS_D71 // => ORI + LU52I_D + BSTRINS_D72 // TmpVal = (LU12I_W | ORI) or (ORI | LU52I_D)73 // The BSTRINS_D instruction will use the `TmpVal` to construct the `Val`.74 uint64_t TmpVal1 = 0;75 uint64_t TmpVal2 = 0;76 switch (Insts[0].Opc) {77 default:78 llvm_unreachable("unexpected opcode");79 break;80 case LoongArch::LU12I_W:81 if (Insts[1].Opc == LoongArch::ORI) {82 TmpVal1 = Insts[1].Imm;83 if (N == 3)84 break;85 TmpVal2 = static_cast<uint64_t>(Insts[3].Imm) << 52 | TmpVal1;86 }87 TmpVal1 |= static_cast<uint64_t>(Insts[0].Imm) << 12;88 break;89 case LoongArch::ORI:90 case LoongArch::ADDI_W:91 TmpVal1 = Insts[0].Imm;92 break;93 }94 95 uint64_t Msb = 32;96 uint64_t HighMask = ~((1ULL << (Msb + 1)) - 1);97 for (; Msb < 64; ++Msb, HighMask = HighMask << 1) {98 for (uint64_t Lsb = Msb; Lsb > 0; --Lsb) {99 uint64_t LowMask = (1ULL << Lsb) - 1;100 uint64_t Mask = HighMask | LowMask;101 uint64_t LsbToZero = TmpVal1 & ((1ULL << (Msb - Lsb + 1)) - 1);102 uint64_t MsbToLsb = LsbToZero << Lsb;103 if ((MsbToLsb | (TmpVal1 & Mask)) == (uint64_t)Val) {104 if (Insts[1].Opc == LoongArch::ORI && N == 3)105 Insts[0] = Insts[1];106 Insts.pop_back_n(2);107 Insts.push_back(Inst(LoongArch::BSTRINS_D, Msb << 32 | Lsb));108 return Insts;109 }110 if (TmpVal2 != 0) {111 LsbToZero = TmpVal2 & ((1ULL << (Msb - Lsb + 1)) - 1);112 MsbToLsb = LsbToZero << Lsb;113 if ((MsbToLsb | (TmpVal2 & Mask)) == (uint64_t)Val) {114 Insts[0] = Insts[1];115 Insts[1] = Insts[3];116 Insts.pop_back_n(2);117 Insts.push_back(Inst(LoongArch::BSTRINS_D, Msb << 32 | Lsb));118 return Insts;119 }120 }121 }122 }123 124 return Insts;125}126