dynarmic/src/ir_opt/a32_constant_memory_reads_pass.cpp

/* 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.
 */

#include <dynarmic/A32/callbacks.h>

#include "frontend/ir/basic_block.h"
#include "frontend/ir/opcodes.h"
#include "ir_opt/passes.h"

namespace Dynarmic {
namespace Optimization {

void A32ConstantMemoryReads(IR::Block& block, const A32::UserCallbacks::Memory& memory_callbacks) {
    for (auto& inst : block) {
        switch (inst.GetOpcode()) {
        case IR::Opcode::A32SetCFlag: {
            IR::Value arg = inst.GetArg(0);
            if (!arg.IsImmediate() && arg.GetInst()->GetOpcode() == IR::Opcode::A32GetCFlag) {
                inst.Invalidate();
            }
            break;
        }
        case IR::Opcode::A32ReadMemory8: {
            if (!inst.AreAllArgsImmediates())
                break;

            u32 vaddr = inst.GetArg(0).GetU32();
            if (memory_callbacks.IsReadOnlyMemory(vaddr)) {
                u8 value_from_memory = memory_callbacks.Read8(vaddr);
                inst.ReplaceUsesWith(IR::Value{value_from_memory});
            }
            break;
        }
        case IR::Opcode::A32ReadMemory16: {
            if (!inst.AreAllArgsImmediates())
                break;

            u32 vaddr = inst.GetArg(0).GetU32();
            if (memory_callbacks.IsReadOnlyMemory(vaddr)) {
                u16 value_from_memory = memory_callbacks.Read16(vaddr);
                inst.ReplaceUsesWith(IR::Value{value_from_memory});
            }
            break;
        }
        case IR::Opcode::A32ReadMemory32: {
            if (!inst.AreAllArgsImmediates())
                break;

            u32 vaddr = inst.GetArg(0).GetU32();
            if (memory_callbacks.IsReadOnlyMemory(vaddr)) {
                u32 value_from_memory = memory_callbacks.Read32(vaddr);
                inst.ReplaceUsesWith(IR::Value{value_from_memory});
            }
            break;
        }
        case IR::Opcode::A32ReadMemory64: {
            if (!inst.AreAllArgsImmediates())
                break;

            u32 vaddr = inst.GetArg(0).GetU32();
            if (memory_callbacks.IsReadOnlyMemory(vaddr)) {
                u64 value_from_memory = memory_callbacks.Read64(vaddr);
                inst.ReplaceUsesWith(IR::Value{value_from_memory});
            }
            break;
        }
        default:
            break;
        }
    }
}

} // namespace Optimization
} // namespace Dynarmic