1 //=- WebAssemblyMachineFunctionInfo.cpp - WebAssembly Machine Function Info -=// 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 implements WebAssembly-specific per-machine-function 11 /// information. 12 /// 13 //===----------------------------------------------------------------------===// 14 15 #include "WebAssemblyMachineFunctionInfo.h" 16 #include "WebAssemblyISelLowering.h" 17 #include "WebAssemblySubtarget.h" 18 #include "llvm/CodeGen/Analysis.h" 19 using namespace llvm; 20 21 WebAssemblyFunctionInfo::~WebAssemblyFunctionInfo() = default; // anchor. 22 23 void WebAssemblyFunctionInfo::initWARegs() { 24 assert(WARegs.empty()); 25 unsigned Reg = UnusedReg; 26 WARegs.resize(MF.getRegInfo().getNumVirtRegs(), Reg); 27 } 28 29 void llvm::computeLegalValueVTs(const Function &F, const TargetMachine &TM, 30 Type *Ty, SmallVectorImpl<MVT> &ValueVTs) { 31 const DataLayout &DL(F.getParent()->getDataLayout()); 32 const WebAssemblyTargetLowering &TLI = 33 *TM.getSubtarget<WebAssemblySubtarget>(F).getTargetLowering(); 34 SmallVector<EVT, 4> VTs; 35 ComputeValueVTs(TLI, DL, Ty, VTs); 36 37 for (EVT VT : VTs) { 38 unsigned NumRegs = TLI.getNumRegisters(F.getContext(), VT); 39 MVT RegisterVT = TLI.getRegisterType(F.getContext(), VT); 40 for (unsigned I = 0; I != NumRegs; ++I) 41 ValueVTs.push_back(RegisterVT); 42 } 43 } 44 45 void llvm::computeSignatureVTs(const FunctionType *Ty, 46 const Function *TargetFunc, 47 const Function &ContextFunc, 48 const TargetMachine &TM, 49 SmallVectorImpl<MVT> &Params, 50 SmallVectorImpl<MVT> &Results) { 51 computeLegalValueVTs(ContextFunc, TM, Ty->getReturnType(), Results); 52 53 MVT PtrVT = MVT::getIntegerVT(TM.createDataLayout().getPointerSizeInBits()); 54 if (Results.size() > 1 && 55 !TM.getSubtarget<WebAssemblySubtarget>(ContextFunc).hasMultivalue()) { 56 // WebAssembly can't lower returns of multiple values without demoting to 57 // sret unless multivalue is enabled (see 58 // WebAssemblyTargetLowering::CanLowerReturn). So replace multiple return 59 // values with a poitner parameter. 60 Results.clear(); 61 Params.push_back(PtrVT); 62 } 63 64 for (auto *Param : Ty->params()) 65 computeLegalValueVTs(ContextFunc, TM, Param, Params); 66 if (Ty->isVarArg()) 67 Params.push_back(PtrVT); 68 69 // For swiftcc, emit additional swiftself and swifterror parameters 70 // if there aren't. These additional parameters are also passed for caller. 71 // They are necessary to match callee and caller signature for indirect 72 // call. 73 74 if (TargetFunc && TargetFunc->getCallingConv() == CallingConv::Swift) { 75 MVT PtrVT = MVT::getIntegerVT(TM.createDataLayout().getPointerSizeInBits()); 76 bool HasSwiftErrorArg = false; 77 bool HasSwiftSelfArg = false; 78 for (const auto &Arg : TargetFunc->args()) { 79 HasSwiftErrorArg |= Arg.hasAttribute(Attribute::SwiftError); 80 HasSwiftSelfArg |= Arg.hasAttribute(Attribute::SwiftSelf); 81 } 82 if (!HasSwiftErrorArg) 83 Params.push_back(PtrVT); 84 if (!HasSwiftSelfArg) 85 Params.push_back(PtrVT); 86 } 87 } 88 89 void llvm::valTypesFromMVTs(const ArrayRef<MVT> &In, 90 SmallVectorImpl<wasm::ValType> &Out) { 91 for (MVT Ty : In) 92 Out.push_back(WebAssembly::toValType(Ty)); 93 } 94 95 std::unique_ptr<wasm::WasmSignature> 96 llvm::signatureFromMVTs(const SmallVectorImpl<MVT> &Results, 97 const SmallVectorImpl<MVT> &Params) { 98 auto Sig = std::make_unique<wasm::WasmSignature>(); 99 valTypesFromMVTs(Results, Sig->Returns); 100 valTypesFromMVTs(Params, Sig->Params); 101 return Sig; 102 } 103 104 yaml::WebAssemblyFunctionInfo::WebAssemblyFunctionInfo( 105 const llvm::WebAssemblyFunctionInfo &MFI) 106 : CFGStackified(MFI.isCFGStackified()) {} 107 108 void yaml::WebAssemblyFunctionInfo::mappingImpl(yaml::IO &YamlIO) { 109 MappingTraits<WebAssemblyFunctionInfo>::mapping(YamlIO, *this); 110 } 111 112 void WebAssemblyFunctionInfo::initializeBaseYamlFields( 113 const yaml::WebAssemblyFunctionInfo &YamlMFI) { 114 CFGStackified = YamlMFI.CFGStackified; 115 } 116