1 //===-- LoongArchSubtarget.cpp - LoongArch Subtarget Information -*- 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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements the LoongArch specific subclass of TargetSubtargetInfo. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "LoongArchSubtarget.h" 14 #include "LoongArchFrameLowering.h" 15 #include "MCTargetDesc/LoongArchBaseInfo.h" 16 17 using namespace llvm; 18 19 #define DEBUG_TYPE "loongarch-subtarget" 20 21 #define GET_SUBTARGETINFO_TARGET_DESC 22 #define GET_SUBTARGETINFO_CTOR 23 #include "LoongArchGenSubtargetInfo.inc" 24 25 void LoongArchSubtarget::anchor() {} 26 27 LoongArchSubtarget &LoongArchSubtarget::initializeSubtargetDependencies( 28 const Triple &TT, StringRef CPU, StringRef TuneCPU, StringRef FS, 29 StringRef ABIName) { 30 bool Is64Bit = TT.isArch64Bit(); 31 if (CPU.empty() || CPU == "generic") 32 CPU = Is64Bit ? "generic-la64" : "generic-la32"; 33 34 if (TuneCPU.empty()) 35 TuneCPU = CPU; 36 37 ParseSubtargetFeatures(CPU, TuneCPU, FS); 38 initializeProperties(TuneCPU); 39 if (Is64Bit) { 40 GRLenVT = MVT::i64; 41 GRLen = 64; 42 } 43 44 if (HasLA32 == HasLA64) 45 report_fatal_error("Please use one feature of 32bit and 64bit."); 46 47 if (Is64Bit && HasLA32) 48 report_fatal_error("Feature 32bit should be used for loongarch32 target."); 49 50 if (!Is64Bit && HasLA64) 51 report_fatal_error("Feature 64bit should be used for loongarch64 target."); 52 53 TargetABI = LoongArchABI::computeTargetABI(TT, ABIName); 54 55 return *this; 56 } 57 58 void LoongArchSubtarget::initializeProperties(StringRef TuneCPU) { 59 // Initialize CPU specific properties. We should add a tablegen feature for 60 // this in the future so we can specify it together with the subtarget 61 // features. 62 63 // TODO: Check TuneCPU and override defaults (that are for LA464) once we 64 // support optimizing for more uarchs. 65 66 // Default to the alignment settings empirically confirmed to perform best 67 // on LA464, with 4-wide instruction fetch and decode stages. These settings 68 // can also be overridden in initializeProperties. 69 // 70 // We default to such higher-than-minimum alignments because we assume that: 71 // 72 // * these settings should benefit most existing uarchs/users, 73 // * future general-purpose LoongArch cores are likely to have issue widths 74 // equal to or wider than 4, 75 // * instruction sequences best for LA464 should not pessimize other future 76 // uarchs, and 77 // * narrower cores would not suffer much (aside from slightly increased 78 // ICache footprint maybe), compared to the gains everywhere else. 79 PrefFunctionAlignment = Align(32); 80 PrefLoopAlignment = Align(16); 81 MaxBytesForAlignment = 16; 82 } 83 84 LoongArchSubtarget::LoongArchSubtarget(const Triple &TT, StringRef CPU, 85 StringRef TuneCPU, StringRef FS, 86 StringRef ABIName, 87 const TargetMachine &TM) 88 : LoongArchGenSubtargetInfo(TT, CPU, TuneCPU, FS), 89 FrameLowering( 90 initializeSubtargetDependencies(TT, CPU, TuneCPU, FS, ABIName)), 91 InstrInfo(*this), RegInfo(getHwMode()), TLInfo(TM, *this) {} 92