dynarmic/src/frontend/A32/location_descriptor.h
Lioncash 7bb5440507 general: Mark hash functions as noexcept
Generally hash functions shouldn't throw exceptions. It's also a
requirement for the standard library-provided hash functions to not
throw exceptions.

An exception to this rule is made for user-defined specializations,
however we can just be consistent with the standard library on this to
allow it to play nicer with it.

While we're at it, we can also make the std::less specializations
noexcpet as well, since they also can't throw.
2020-04-22 21:01:43 +01:00

125 lines
4 KiB
C++

/* This file is part of the dynarmic project.
* Copyright (c) 2016 MerryMage
* This software may be used and distributed according to the terms of the GNU
* General Public License version 2 or any later version.
*/
#pragma once
#include <functional>
#include <iosfwd>
#include <tuple>
#include "common/common_types.h"
#include "frontend/A32/FPSCR.h"
#include "frontend/A32/PSR.h"
#include "frontend/ir/location_descriptor.h"
namespace Dynarmic::A32 {
/**
* LocationDescriptor describes the location of a basic block.
* The location is not solely based on the PC because other flags influence the way
* instructions should be translated. The CPSR.T flag is most notable since it
* tells us if the processor is in Thumb or Arm mode.
*/
class LocationDescriptor {
public:
// Indicates bits that should be preserved within descriptors.
static constexpr u32 CPSR_MODE_MASK = 0x00000220;
static constexpr u32 FPSCR_MODE_MASK = 0x03F79F00;
LocationDescriptor(u32 arm_pc, PSR cpsr, FPSCR fpscr)
: arm_pc(arm_pc), cpsr(cpsr.Value() & CPSR_MODE_MASK), fpscr(fpscr.Value() & FPSCR_MODE_MASK) {}
explicit LocationDescriptor(const IR::LocationDescriptor& o) {
arm_pc = o.Value() >> 32;
cpsr.T(o.Value() & 1);
cpsr.E(o.Value() & 2);
fpscr = o.Value() & FPSCR_MODE_MASK;
}
u32 PC() const { return arm_pc; }
bool TFlag() const { return cpsr.T(); }
bool EFlag() const { return cpsr.E(); }
A32::PSR CPSR() const { return cpsr; }
A32::FPSCR FPSCR() const { return fpscr; }
bool operator == (const LocationDescriptor& o) const {
return std::tie(arm_pc, cpsr, fpscr) == std::tie(o.arm_pc, o.cpsr, o.fpscr);
}
bool operator != (const LocationDescriptor& o) const {
return !operator==(o);
}
LocationDescriptor SetPC(u32 new_arm_pc) const {
return LocationDescriptor(new_arm_pc, cpsr, fpscr);
}
LocationDescriptor AdvancePC(int amount) const {
return LocationDescriptor(static_cast<u32>(arm_pc + amount), cpsr, fpscr);
}
LocationDescriptor SetTFlag(bool new_tflag) const {
PSR new_cpsr = cpsr;
new_cpsr.T(new_tflag);
return LocationDescriptor(arm_pc, new_cpsr, fpscr);
}
LocationDescriptor SetEFlag(bool new_eflag) const {
PSR new_cpsr = cpsr;
new_cpsr.E(new_eflag);
return LocationDescriptor(arm_pc, new_cpsr, fpscr);
}
LocationDescriptor SetFPSCR(u32 new_fpscr) const {
return LocationDescriptor(arm_pc, cpsr, A32::FPSCR{new_fpscr & FPSCR_MODE_MASK});
}
u64 UniqueHash() const noexcept {
// This value MUST BE UNIQUE.
// This calculation has to match up with EmitX64::EmitTerminalPopRSBHint
const u64 pc_u64 = u64(arm_pc) << 32;
const u64 fpscr_u64 = u64(fpscr.Value());
const u64 t_u64 = cpsr.T() ? 1 : 0;
const u64 e_u64 = cpsr.E() ? 2 : 0;
return pc_u64 | fpscr_u64 | t_u64 | e_u64;
}
operator IR::LocationDescriptor() const {
return IR::LocationDescriptor{UniqueHash()};
}
private:
u32 arm_pc; ///< Current program counter value.
PSR cpsr; ///< Current program status register.
A32::FPSCR fpscr; ///< Floating point status control register.
};
/**
* Provides a string representation of a LocationDescriptor.
*
* @param o Output stream
* @param descriptor The descriptor to get a string representation of
*/
std::ostream& operator<<(std::ostream& o, const LocationDescriptor& descriptor);
} // namespace Dynarmic::A32
namespace std {
template <>
struct less<Dynarmic::A32::LocationDescriptor> {
bool operator()(const Dynarmic::A32::LocationDescriptor& x, const Dynarmic::A32::LocationDescriptor& y) const noexcept {
return x.UniqueHash() < y.UniqueHash();
}
};
template <>
struct hash<Dynarmic::A32::LocationDescriptor> {
size_t operator()(const Dynarmic::A32::LocationDescriptor& x) const noexcept {
return std::hash<u64>()(x.UniqueHash());
}
};
} // namespace std