qemu/target-unicore32/op_helper.c

249 lines
5.2 KiB
C
Raw Normal View History

/*
* 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 "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();
}
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));
}
}