llvm-project/llvm/lib/Target/WebAssembly/WebAssemblyMachineFunctionInfo.cpp
Thomas Lively 00f9e5aa76 [WebAssembly] Make returns variadic
Summary:
This is necessary and sufficient to get simple cases of multiple
return working with multivalue enabled. More complex cases will
require block and loop signatures to be generalized to potentially be
type indices as well.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68684

llvm-svn: 374235
2019-10-09 21:42:08 +00:00

95 lines
3.4 KiB
C++

//=- WebAssemblyMachineFunctionInfo.cpp - WebAssembly Machine Function Info -=//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file implements WebAssembly-specific per-machine-function
/// information.
///
//===----------------------------------------------------------------------===//
#include "WebAssemblyMachineFunctionInfo.h"
#include "WebAssemblyISelLowering.h"
#include "WebAssemblySubtarget.h"
#include "llvm/CodeGen/Analysis.h"
using namespace llvm;
WebAssemblyFunctionInfo::~WebAssemblyFunctionInfo() = default; // anchor.
void WebAssemblyFunctionInfo::initWARegs() {
assert(WARegs.empty());
unsigned Reg = UnusedReg;
WARegs.resize(MF.getRegInfo().getNumVirtRegs(), Reg);
}
void llvm::computeLegalValueVTs(const Function &F, const TargetMachine &TM,
Type *Ty, SmallVectorImpl<MVT> &ValueVTs) {
const DataLayout &DL(F.getParent()->getDataLayout());
const WebAssemblyTargetLowering &TLI =
*TM.getSubtarget<WebAssemblySubtarget>(F).getTargetLowering();
SmallVector<EVT, 4> VTs;
ComputeValueVTs(TLI, DL, Ty, VTs);
for (EVT VT : VTs) {
unsigned NumRegs = TLI.getNumRegisters(F.getContext(), VT);
MVT RegisterVT = TLI.getRegisterType(F.getContext(), VT);
for (unsigned I = 0; I != NumRegs; ++I)
ValueVTs.push_back(RegisterVT);
}
}
void llvm::computeSignatureVTs(const FunctionType *Ty, const Function &F,
const TargetMachine &TM,
SmallVectorImpl<MVT> &Params,
SmallVectorImpl<MVT> &Results) {
computeLegalValueVTs(F, TM, Ty->getReturnType(), Results);
MVT PtrVT = MVT::getIntegerVT(TM.createDataLayout().getPointerSizeInBits());
if (Results.size() > 1 &&
!TM.getSubtarget<WebAssemblySubtarget>(F).hasMultivalue()) {
// WebAssembly can't lower returns of multiple values without demoting to
// sret unless multivalue is enabled (see
// WebAssemblyTargetLowering::CanLowerReturn). So replace multiple return
// values with a poitner parameter.
Results.clear();
Params.push_back(PtrVT);
}
for (auto *Param : Ty->params())
computeLegalValueVTs(F, TM, Param, Params);
if (Ty->isVarArg())
Params.push_back(PtrVT);
}
void llvm::valTypesFromMVTs(const ArrayRef<MVT> &In,
SmallVectorImpl<wasm::ValType> &Out) {
for (MVT Ty : In)
Out.push_back(WebAssembly::toValType(Ty));
}
std::unique_ptr<wasm::WasmSignature>
llvm::signatureFromMVTs(const SmallVectorImpl<MVT> &Results,
const SmallVectorImpl<MVT> &Params) {
auto Sig = std::make_unique<wasm::WasmSignature>();
valTypesFromMVTs(Results, Sig->Returns);
valTypesFromMVTs(Params, Sig->Params);
return Sig;
}
yaml::WebAssemblyFunctionInfo::WebAssemblyFunctionInfo(
const llvm::WebAssemblyFunctionInfo &MFI)
: CFGStackified(MFI.isCFGStackified()) {}
void yaml::WebAssemblyFunctionInfo::mappingImpl(yaml::IO &YamlIO) {
MappingTraits<WebAssemblyFunctionInfo>::mapping(YamlIO, *this);
}
void WebAssemblyFunctionInfo::initializeBaseYamlFields(
const yaml::WebAssemblyFunctionInfo &YamlMFI) {
CFGStackified = YamlMFI.CFGStackified;
}