Archipelago » qemu

/*

 *  UniCore32 helper routines

 *

 * Copyright (C) 2010-2011 GUAN Xue-tao

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#include "cpu.h"

#include "dyngen-exec.h"

#include "helper.h"

#define SIGNBIT (uint32_t)0x80000000

#define SIGNBIT64 ((uint64_t)1 << 63)

void HELPER(exception)(uint32_t excp)

{

    env->exception_index = excp;

    cpu_loop_exit(env);

}

static target_ulong asr_read(void)

{

    int ZF;

    ZF = (env->ZF == 0);

    return env->uncached_asr | (env->NF & 0x80000000) | (ZF << 30) |

        (env->CF << 29) | ((env->VF & 0x80000000) >> 3);

}

target_ulong cpu_asr_read(CPUState *env1)

{

    CPUState *saved_env;

    target_ulong ret;

    saved_env = env;

    env = env1;

    ret = asr_read();

    env = saved_env;

    return ret;

}

target_ulong HELPER(asr_read)(void)

{

    return asr_read();

}

static void asr_write(target_ulong val, target_ulong mask)

{

    if (mask & ASR_NZCV) {

        env->ZF = (~val) & ASR_Z;

        env->NF = val;

        env->CF = (val >> 29) & 1;

        env->VF = (val << 3) & 0x80000000;

    }

    if ((env->uncached_asr ^ val) & mask & ASR_M) {

        switch_mode(env, val & ASR_M);

    }

    mask &= ~ASR_NZCV;

    env->uncached_asr = (env->uncached_asr & ~mask) | (val & mask);

}

void cpu_asr_write(CPUState *env1, target_ulong val, target_ulong mask)

{

    CPUState *saved_env;

    saved_env = env;

    env = env1;

    asr_write(val, mask);

    env = saved_env;

}

void HELPER(asr_write)(target_ulong val, target_ulong mask)

{

    asr_write(val, mask);

}

/* Access to user mode registers from privileged modes.  */

uint32_t HELPER(get_user_reg)(uint32_t regno)

{

    uint32_t val;

    if (regno == 29) {

        val = env->banked_r29[0];

    } else if (regno == 30) {

        val = env->banked_r30[0];

    } else {

        val = env->regs[regno];

    }

    return val;

}

void HELPER(set_user_reg)(uint32_t regno, uint32_t val)

{

    if (regno == 29) {

        env->banked_r29[0] = val;

    } else if (regno == 30) {

        env->banked_r30[0] = val;

    } else {

        env->regs[regno] = val;

    }

}

/* ??? Flag setting arithmetic is awkward because we need to do comparisons.

   The only way to do that in TCG is a conditional branch, which clobbers

   all our temporaries.  For now implement these as helper functions.  */

uint32_t HELPER(add_cc)(uint32_t a, uint32_t b)

{

    uint32_t result;

    result = a + b;

    env->NF = env->ZF = result;

    env->CF = result < a;

    env->VF = (a ^ b ^ -1) & (a ^ result);

    return result;

}

uint32_t HELPER(adc_cc)(uint32_t a, uint32_t b)

{

    uint32_t result;

    if (!env->CF) {

        result = a + b;

        env->CF = result < a;

    } else {

        result = a + b + 1;

        env->CF = result <= a;

    }

    env->VF = (a ^ b ^ -1) & (a ^ result);

    env->NF = env->ZF = result;

    return result;

}

uint32_t HELPER(sub_cc)(uint32_t a, uint32_t b)

{

    uint32_t result;

    result = a - b;

    env->NF = env->ZF = result;

    env->CF = a >= b;

    env->VF = (a ^ b) & (a ^ result);

    return result;

}

uint32_t HELPER(sbc_cc)(uint32_t a, uint32_t b)

{

    uint32_t result;

    if (!env->CF) {

        result = a - b - 1;

        env->CF = a > b;

    } else {

        result = a - b;

        env->CF = a >= b;

    }

    env->VF = (a ^ b) & (a ^ result);

    env->NF = env->ZF = result;

    return result;

}

/* Similarly for variable shift instructions.  */

uint32_t HELPER(shl)(uint32_t x, uint32_t i)

{

    int shift = i & 0xff;

    if (shift >= 32) {

        return 0;

    }

    return x << shift;

}

uint32_t HELPER(shr)(uint32_t x, uint32_t i)

{

    int shift = i & 0xff;

    if (shift >= 32) {

        return 0;

    }

    return (uint32_t)x >> shift;

}

uint32_t HELPER(sar)(uint32_t x, uint32_t i)

{

    int shift = i & 0xff;

    if (shift >= 32) {

        shift = 31;

    }

    return (int32_t)x >> shift;

}

uint32_t HELPER(shl_cc)(uint32_t x, uint32_t i)

{

    int shift = i & 0xff;

    if (shift >= 32) {

        if (shift == 32) {

            env->CF = x & 1;

        } else {

            env->CF = 0;

        }

        return 0;

    } else if (shift != 0) {

        env->CF = (x >> (32 - shift)) & 1;

        return x << shift;

    }

    return x;

}

uint32_t HELPER(shr_cc)(uint32_t x, uint32_t i)

{

    int shift = i & 0xff;

    if (shift >= 32) {

        if (shift == 32) {

            env->CF = (x >> 31) & 1;

        } else {

            env->CF = 0;

        }

        return 0;

    } else if (shift != 0) {

        env->CF = (x >> (shift - 1)) & 1;

        return x >> shift;

    }

    return x;

}

uint32_t HELPER(sar_cc)(uint32_t x, uint32_t i)

{

    int shift = i & 0xff;

    if (shift >= 32) {

        env->CF = (x >> 31) & 1;

        return (int32_t)x >> 31;

    } else if (shift != 0) {

        env->CF = (x >> (shift - 1)) & 1;

        return (int32_t)x >> shift;

    }

    return x;

}

uint32_t HELPER(ror_cc)(uint32_t x, uint32_t i)

{

    int shift1, shift;

    shift1 = i & 0xff;

    shift = shift1 & 0x1f;

    if (shift == 0) {

        if (shift1 != 0) {

            env->CF = (x >> 31) & 1;

        }

        return x;

    } else {

        env->CF = (x >> (shift - 1)) & 1;

        return ((uint32_t)x >> shift) | (x << (32 - shift));

    }

}