flycast/core/hw/sh4/sh4_cycles.h

85 lines
2.1 KiB
C++

/*
Copyright 2023 flyinghead
This file is part of Flycast.
Flycast is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
Flycast is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Flycast. If not, see <https://www.gnu.org/licenses/>.
*/
#pragma once
#include "types.h"
#include "sh4_opcode_list.h"
#include "sh4_if.h"
#include "sh4_sched.h"
class Sh4Cycles
{
public:
Sh4Cycles(int cpuRatio = 1) : cpuRatio(cpuRatio) {}
void init(Sh4Context *ctx) {
this->ctx = ctx;
}
void executeCycles(u16 op)
{
ctx->cycle_counter -= countCycles(op);
}
void addCycles(int cycles) const
{
ctx->cycle_counter -= cycles;
}
void addReadAccessCycles(u32 addr, u32 size) const
{
ctx->cycle_counter -= readAccessCycles(addr, size);
}
void addWriteAccessCycles(u32 addr, u32 size) const
{
ctx->cycle_counter -= writeAccessCycles(addr, size);
}
int countCycles(u16 op);
void reset()
{
lastUnit = CO;
memOps = 0;
}
u64 now() {
return sh4_sched_now64() + SH4_TIMESLICE - ctx->cycle_counter;
}
int readAccessCycles(u32 addr, u32 size) const {
return readExternalAccessCycles(addr, size) * 2 * cpuRatio;
}
int writeAccessCycles(u32 addr, u32 size) const {
return writeExternalAccessCycles(addr, size) * 2 * cpuRatio;
}
private:
// Returns the number of external cycles (100 MHz) needed for a sized read at the given address
static int readExternalAccessCycles(u32 addr, u32 size);
// Returns the number of external cycles (100 MHz) needed for a sized write at the given address
static int writeExternalAccessCycles(u32 addr, u32 size);
sh4_eu lastUnit = CO;
const int cpuRatio;
int memOps = 0;
Sh4Context *ctx = nullptr;
};