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Tag: 20120517
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/*
* ARM helper routines
*
* Copyright (c) 2005-2007 CodeSourcery, LLC
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "exec.h"
#include "helpers.h"
#define SIGNBIT (uint32_t)0x80000000
#define SIGNBIT64 ((uint64_t)1 << 63)
void raise_exception(int tt)
{
env->exception_index = tt;
cpu_loop_exit();
}
uint32_t HELPER(neon_tbl)(uint32_t ireg, uint32_t def,
uint32_t rn, uint32_t maxindex)
{
uint32_t val;
uint32_t tmp;
int index;
int shift;
uint64_t *table;
table = (uint64_t *)&env->vfp.regs[rn];
val = 0;
for (shift = 0; shift < 32; shift += 8) {
index = (ireg >> shift) & 0xff;
if (index < maxindex) {
tmp = (table[index >> 3] >> ((index & 7) << 3)) & 0xff;
val |= tmp << shift;
} else {
val |= def & (0xff << shift);
}
}
return val;
}
#if !defined(CONFIG_USER_ONLY)
#define MMUSUFFIX _mmu
#define SHIFT 0
#include "softmmu_template.h"
#define SHIFT 1
#include "softmmu_template.h"
#define SHIFT 2
#include "softmmu_template.h"
#define SHIFT 3
#include "softmmu_template.h"
/* try to fill the TLB and return an exception if error. If retaddr is
NULL, it means that the function was called in C code (i.e. not
from generated code or from helper.c) */
/* XXX: fix it to restore all registers */
void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
{
TranslationBlock *tb;
CPUState *saved_env;
unsigned long pc;
int ret;
/* XXX: hack to restore env in all cases, even if not called from
generated code */
saved_env = env;
env = cpu_single_env;
ret = cpu_arm_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);
if (unlikely(ret)) {
if (retaddr) {
/* now we have a real cpu fault */
pc = (unsigned long)retaddr;
tb = tb_find_pc(pc);
if (tb) {
/* the PC is inside the translated code. It means that we have
a virtual CPU fault */
cpu_restore_state(tb, env, pc, NULL);
}
}
raise_exception(env->exception_index);
}
env = saved_env;
}
#endif
/* FIXME: Pass an axplicit pointer to QF to CPUState, and move saturating
instructions into helper.c */
uint32_t HELPER(add_setq)(uint32_t a, uint32_t b)
{
uint32_t res = a + b;
if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT))
env->QF = 1;
return res;
}
uint32_t HELPER(add_saturate)(uint32_t a, uint32_t b)
{
uint32_t res = a + b;
if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) {
env->QF = 1;
res = ~(((int32_t)a >> 31) ^ SIGNBIT);
}
return res;
}
uint32_t HELPER(sub_saturate)(uint32_t a, uint32_t b)
{
uint32_t res = a - b;
if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) {
env->QF = 1;
res = ~(((int32_t)a >> 31) ^ SIGNBIT);
}
return res;
}
uint32_t HELPER(double_saturate)(int32_t val)
{
uint32_t res;
if (val >= 0x40000000) {
res = ~SIGNBIT;
env->QF = 1;
} else if (val <= (int32_t)0xc0000000) {
res = SIGNBIT;
env->QF = 1;
} else {
res = val << 1;
}
return res;
}
uint32_t HELPER(add_usaturate)(uint32_t a, uint32_t b)
{
uint32_t res = a + b;
if (res < a) {
env->QF = 1;
res = ~0;
}
return res;
}
uint32_t HELPER(sub_usaturate)(uint32_t a, uint32_t b)
{
uint32_t res = a - b;
if (res > a) {
env->QF = 1;
res = 0;
}
return res;
}
/* Signed saturation. */
static inline uint32_t do_ssat(int32_t val, int shift)
{
int32_t top;
uint32_t mask;
top = val >> shift;
mask = (1u << shift) - 1;
if (top > 0) {
env->QF = 1;
return mask;
} else if (top < -1) {
env->QF = 1;
return ~mask;
}
return val;
}
/* Unsigned saturation. */
static inline uint32_t do_usat(int32_t val, int shift)
{
uint32_t max;
max = (1u << shift) - 1;
if (val < 0) {
env->QF = 1;
return 0;
} else if (val > max) {
env->QF = 1;
return max;
}
return val;
}
/* Signed saturate. */
uint32_t HELPER(ssat)(uint32_t x, uint32_t shift)
{
return do_ssat(x, shift);
}
/* Dual halfword signed saturate. */
uint32_t HELPER(ssat16)(uint32_t x, uint32_t shift)
{
uint32_t res;
res = (uint16_t)do_ssat((int16_t)x, shift);
res |= do_ssat(((int32_t)x) >> 16, shift) << 16;
return res;
}
/* Unsigned saturate. */
uint32_t HELPER(usat)(uint32_t x, uint32_t shift)
{
return do_usat(x, shift);
}
/* Dual halfword unsigned saturate. */
uint32_t HELPER(usat16)(uint32_t x, uint32_t shift)
{
uint32_t res;
res = (uint16_t)do_usat((int16_t)x, shift);
res |= do_usat(((int32_t)x) >> 16, shift) << 16;
return res;
}
void HELPER(wfi)(void)
{
env->exception_index = EXCP_HLT;
env->halted = 1;
cpu_loop_exit();
}
void HELPER(exception)(uint32_t excp)
{
env->exception_index = excp;
cpu_loop_exit();
}
uint32_t HELPER(cpsr_read)(void)
{
return cpsr_read(env) & ~CPSR_EXEC;
}
void HELPER(cpsr_write)(uint32_t val, uint32_t mask)
{
cpsr_write(env, val, mask);
}
/* Access to user mode registers from privileged modes. */
uint32_t HELPER(get_user_reg)(uint32_t regno)
{
uint32_t val;
if (regno == 13) {
val = env->banked_r13[0];
} else if (regno == 14) {
val = env->banked_r14[0];
} else if (regno >= 8
&& (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
val = env->usr_regs[regno - 8];
} else {
val = env->regs[regno];
}
return val;
}
void HELPER(set_user_reg)(uint32_t regno, uint32_t val)
{
if (regno == 13) {
env->banked_r13[0] = val;
} else if (regno == 14) {
env->banked_r14[0] = val;
} else if (regno >= 8
&& (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) {
env->usr_regs[regno - 8] = 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));
}
}
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