unicorn/qemu/target-m68k/op_helper.c
Laurent Vivier 77b8b2f3b8
target-m68k: add 680x0 divu/divs variants
Update helper to set the throwing location in case of div-by-0.
Cleanup divX.w and add quad word variants of divX.l.

Backports commit 0ccb9c1d8128a020720d5c6abf99a470742a1b94 from qemu
2018-03-01 11:38:53 -05:00

354 lines
8.6 KiB
C

/*
* M68K helper routines
*
* Copyright (c) 2007 CodeSourcery
*
* 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 "qemu/osdep.h"
#include "cpu.h"
#include "exec/helper-proto.h"
#include "exec/exec-all.h"
#include "exec/cpu_ldst.h"
#if defined(CONFIG_USER_ONLY)
void m68k_cpu_do_interrupt(CPUState *cs)
{
cs->exception_index = -1;
}
static inline void do_interrupt_m68k_hardirq(CPUM68KState *env)
{
}
#else
extern int semihosting_enabled;
/* 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) */
void tlb_fill(CPUState *cs, target_ulong addr, MMUAccessType access_type,
int mmu_idx, uintptr_t retaddr)
{
int ret;
ret = m68k_cpu_handle_mmu_fault(cs, addr, access_type, mmu_idx);
if (unlikely(ret)) {
if (retaddr) {
/* now we have a real cpu fault */
cpu_restore_state(cs, retaddr);
}
cpu_loop_exit(cs);
}
}
static void do_rte(CPUM68KState *env)
{
uint32_t sp;
uint32_t fmt;
sp = env->aregs[7];
fmt = cpu_ldl_kernel(env, sp);
env->pc = cpu_ldl_kernel(env, sp + 4);
sp |= (fmt >> 28) & 3;
env->aregs[7] = sp + 8;
helper_set_sr(env, fmt);
}
static void do_interrupt_all(CPUM68KState *env, int is_hw)
{
CPUState *cs = CPU(m68k_env_get_cpu(env));
uint32_t sp;
uint32_t fmt;
uint32_t retaddr;
uint32_t vector;
fmt = 0;
retaddr = env->pc;
if (!is_hw) {
switch (cs->exception_index) {
case EXCP_RTE:
/* Return from an exception. */
do_rte(env);
return;
case EXCP_HALT_INSN:
cs->halted = 1;
cs->exception_index = EXCP_HLT;
cpu_loop_exit(cs);
return;
}
if (cs->exception_index >= EXCP_TRAP0
&& cs->exception_index <= EXCP_TRAP15) {
/* Move the PC after the trap instruction. */
retaddr += 2;
}
}
vector = cs->exception_index << 2;
fmt |= 0x40000000;
fmt |= vector << 16;
fmt |= env->sr;
fmt |= cpu_m68k_get_ccr(env);
env->sr |= SR_S;
if (is_hw) {
env->sr = (env->sr & ~SR_I) | (env->pending_level << SR_I_SHIFT);
env->sr &= ~SR_M;
}
m68k_switch_sp(env);
sp = env->aregs[7];
fmt |= (sp & 3) << 28;
/* ??? This could cause MMU faults. */
sp &= ~3;
sp -= 4;
cpu_stl_kernel(env, sp, retaddr);
sp -= 4;
cpu_stl_kernel(env, sp, fmt);
env->aregs[7] = sp;
/* Jump to vector. */
env->pc = cpu_ldl_kernel(env, env->vbr + vector);
}
void m68k_cpu_do_interrupt(CPUState *cs)
{
M68kCPU *cpu = M68K_CPU(cs->uc, cs);
CPUM68KState *env = &cpu->env;
do_interrupt_all(env, 0);
}
static inline void do_interrupt_m68k_hardirq(CPUM68KState *env)
{
do_interrupt_all(env, 1);
}
#endif
bool m68k_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
{
M68kCPU *cpu = M68K_CPU(cs->uc, cs);
CPUM68KState *env = &cpu->env;
if (interrupt_request & CPU_INTERRUPT_HARD
&& ((env->sr & SR_I) >> SR_I_SHIFT) < env->pending_level) {
/* Real hardware gets the interrupt vector via an IACK cycle
at this point. Current emulated hardware doesn't rely on
this, so we provide/save the vector when the interrupt is
first signalled. */
cs->exception_index = env->pending_vector;
do_interrupt_m68k_hardirq(env);
return true;
}
return false;
}
static void raise_exception_ra(CPUM68KState *env, int tt, uintptr_t raddr)
{
CPUState *cs = CPU(m68k_env_get_cpu(env));
cs->exception_index = tt;
cpu_loop_exit_restore(cs, raddr);
}
static void raise_exception(CPUM68KState *env, int tt)
{
raise_exception_ra(env, tt, 0);
}
void HELPER(raise_exception)(CPUM68KState *env, uint32_t tt)
{
raise_exception(env, tt);
}
void HELPER(divuw)(CPUM68KState *env, int destr, uint32_t den)
{
uint32_t num = env->dregs[destr];
uint32_t quot, rem;
if (den == 0) {
raise_exception_ra(env, EXCP_DIV0, GETPC());
}
quot = num / den;
rem = num % den;
env->cc_c = 0; /* always cleared, even if overflow */
if (quot > 0xffff) {
env->cc_v = -1;
/* real 68040 keeps N and unset Z on overflow,
* whereas documentation says "undefined"
*/
env->cc_z = 1;
return;
}
env->dregs[destr] = deposit32(quot, 16, 16, rem);
env->cc_z = (int16_t)quot;
env->cc_n = (int16_t)quot;
env->cc_v = 0;
}
void HELPER(divsw)(CPUM68KState *env, int destr, int32_t den)
{
int32_t num = env->dregs[destr];
uint32_t quot, rem;
if (den == 0) {
raise_exception_ra(env, EXCP_DIV0, GETPC());
}
quot = num / den;
rem = num % den;
env->cc_c = 0; /* always cleared, even if overflow */
if (quot != (int16_t)quot) {
env->cc_v = -1;
/* nothing else is modified */
/* real 68040 keeps N and unset Z on overflow,
* whereas documentation says "undefined"
*/
env->cc_z = 1;
return;
}
env->dregs[destr] = deposit32(quot, 16, 16, rem);
env->cc_z = (int16_t)quot;
env->cc_n = (int16_t)quot;
env->cc_v = 0;
}
void HELPER(divul)(CPUM68KState *env, int numr, int regr, uint32_t den)
{
uint32_t num = env->dregs[numr];
uint32_t quot, rem;
if (den == 0) {
raise_exception_ra(env, EXCP_DIV0, GETPC());
}
quot = num / den;
rem = num % den;
env->cc_c = 0;
env->cc_z = quot;
env->cc_n = quot;
env->cc_v = 0;
if (m68k_feature(env, M68K_FEATURE_CF_ISA_A)) {
if (numr == regr) {
env->dregs[numr] = quot;
} else {
env->dregs[regr] = rem;
}
} else {
env->dregs[regr] = rem;
env->dregs[numr] = quot;
}
}
void HELPER(divsl)(CPUM68KState *env, int numr, int regr, int32_t den)
{
int32_t num = env->dregs[numr];
int32_t quot, rem;
if (den == 0) {
raise_exception_ra(env, EXCP_DIV0, GETPC());
}
quot = num / den;
rem = num % den;
env->cc_c = 0;
env->cc_z = quot;
env->cc_n = quot;
env->cc_v = 0;
if (m68k_feature(env, M68K_FEATURE_CF_ISA_A)) {
if (numr == regr) {
env->dregs[numr] = quot;
} else {
env->dregs[regr] = rem;
}
} else {
env->dregs[regr] = rem;
env->dregs[numr] = quot;
}
}
void HELPER(divull)(CPUM68KState *env, int numr, int regr, uint32_t den)
{
uint64_t num = deposit64(env->dregs[numr], 32, 32, env->dregs[regr]);
uint64_t quot;
uint32_t rem;
if (den == 0) {
raise_exception_ra(env, EXCP_DIV0, GETPC());
}
quot = num / den;
rem = num % den;
env->cc_c = 0; /* always cleared, even if overflow */
if (quot > 0xffffffffULL) {
env->cc_v = -1;
/* real 68040 keeps N and unset Z on overflow,
* whereas documentation says "undefined"
*/
env->cc_z = 1;
return;
}
env->cc_z = quot;
env->cc_n = quot;
env->cc_v = 0;
/*
* If Dq and Dr are the same, the quotient is returned.
* therefore we set Dq last.
*/
env->dregs[regr] = rem;
env->dregs[numr] = quot;
}
void HELPER(divsll)(CPUM68KState *env, int numr, int regr, int32_t den)
{
int64_t num = deposit64(env->dregs[numr], 32, 32, env->dregs[regr]);
int64_t quot;
int32_t rem;
if (den == 0) {
raise_exception_ra(env, EXCP_DIV0, GETPC());
}
quot = num / den;
rem = num % den;
env->cc_c = 0; /* always cleared, even if overflow */
if (quot != (int32_t)quot) {
env->cc_v = -1;
/* real 68040 keeps N and unset Z on overflow,
* whereas documentation says "undefined"
*/
env->cc_z = 1;
return;
}
env->cc_z = quot;
env->cc_n = quot;
env->cc_v = 0;
/*
* If Dq and Dr are the same, the quotient is returned.
* therefore we set Dq last.
*/
env->dregs[regr] = rem;
env->dregs[numr] = quot;
}