50 lines · cpp
1//===-- ARMWinEH.cpp - Windows on ARM EH Support Functions ------*- 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 "llvm/Support/ARMWinEH.h"10 11namespace llvm {12namespace ARM {13namespace WinEH {14std::pair<uint16_t, uint32_t> SavedRegisterMask(const RuntimeFunction &RF,15 bool Prologue) {16 uint8_t NumRegisters = RF.Reg();17 uint8_t RegistersVFP = RF.R();18 uint8_t LinkRegister = RF.L();19 uint8_t ChainedFrame = RF.C();20 21 uint16_t GPRMask = (ChainedFrame << 11);22 uint32_t VFPMask = 0;23 24 if (Prologue) {25 GPRMask |= (LinkRegister << 14);26 } else {27 // If Ret != 0, we pop into Lr and return later28 if (RF.Ret() != ReturnType::RT_POP)29 GPRMask |= (LinkRegister << 14);30 else if (!RF.H()) // If H == 0, we pop directly into Pc31 GPRMask |= (LinkRegister << 15);32 // else, Ret == 0 && H == 1, we pop into Pc separately afterwards33 }34 35 if (RegistersVFP)36 VFPMask |= (((1 << ((NumRegisters + 1) % 8)) - 1) << 8);37 else38 GPRMask |= (((1 << (NumRegisters + 1)) - 1) << 4);39 40 if ((PrologueFolding(RF) && Prologue) || (EpilogueFolding(RF) && !Prologue))41 GPRMask |= (((1 << ((RF.StackAdjust() & 0x3) + 1)) - 1)42 << (~RF.StackAdjust() & 0x3));43 44 return {GPRMask, VFPMask};45}46} // namespace WinEH47} // namespace ARM48} // namespace llvm49 50