qemu/target/xtensa/fpu_helper.c
Max Filippov f8c6137016 target/xtensa: implement FPU division and square root
This does not implement all opcodes related to div/sqrt as specified in
the xtensa ISA, partly because the official specification is not
complete and partly because precise implementation is unnecessarily
complex. Instead instructions specific to the div/sqrt sequences are
implemented differently, most of them as nops, but the results of
div/sqrt sequences is preserved.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-08-21 12:48:15 -07:00

449 lines
13 KiB
C

/*
* Copyright (c) 2011 - 2019, Max Filippov, Open Source and Linux Lab.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the Open Source and Linux Lab nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "qemu/osdep.h"
#include "qemu/main-loop.h"
#include "cpu.h"
#include "exec/helper-proto.h"
#include "qemu/host-utils.h"
#include "exec/exec-all.h"
#include "fpu/softfloat.h"
enum {
XTENSA_FP_I = 0x1,
XTENSA_FP_U = 0x2,
XTENSA_FP_O = 0x4,
XTENSA_FP_Z = 0x8,
XTENSA_FP_V = 0x10,
};
enum {
XTENSA_FCR_FLAGS_SHIFT = 2,
XTENSA_FSR_FLAGS_SHIFT = 7,
};
static const struct {
uint32_t xtensa_fp_flag;
int softfloat_fp_flag;
} xtensa_fp_flag_map[] = {
{ XTENSA_FP_I, float_flag_inexact, },
{ XTENSA_FP_U, float_flag_underflow, },
{ XTENSA_FP_O, float_flag_overflow, },
{ XTENSA_FP_Z, float_flag_divbyzero, },
{ XTENSA_FP_V, float_flag_invalid, },
};
void HELPER(wur_fpu2k_fcr)(CPUXtensaState *env, uint32_t v)
{
static const int rounding_mode[] = {
float_round_nearest_even,
float_round_to_zero,
float_round_up,
float_round_down,
};
env->uregs[FCR] = v & 0xfffff07f;
set_float_rounding_mode(rounding_mode[v & 3], &env->fp_status);
}
void HELPER(wur_fpu_fcr)(CPUXtensaState *env, uint32_t v)
{
static const int rounding_mode[] = {
float_round_nearest_even,
float_round_to_zero,
float_round_up,
float_round_down,
};
if (v & 0xfffff000) {
qemu_log_mask(LOG_GUEST_ERROR,
"MBZ field of FCR is written non-zero: %08x\n", v);
}
env->uregs[FCR] = v & 0x0000007f;
set_float_rounding_mode(rounding_mode[v & 3], &env->fp_status);
}
void HELPER(wur_fpu_fsr)(CPUXtensaState *env, uint32_t v)
{
uint32_t flags = v >> XTENSA_FSR_FLAGS_SHIFT;
int fef = 0;
unsigned i;
if (v & 0xfffff000) {
qemu_log_mask(LOG_GUEST_ERROR,
"MBZ field of FSR is written non-zero: %08x\n", v);
}
env->uregs[FSR] = v & 0x00000f80;
for (i = 0; i < ARRAY_SIZE(xtensa_fp_flag_map); ++i) {
if (flags & xtensa_fp_flag_map[i].xtensa_fp_flag) {
fef |= xtensa_fp_flag_map[i].softfloat_fp_flag;
}
}
set_float_exception_flags(fef, &env->fp_status);
}
uint32_t HELPER(rur_fpu_fsr)(CPUXtensaState *env)
{
uint32_t flags = 0;
int fef = get_float_exception_flags(&env->fp_status);
unsigned i;
for (i = 0; i < ARRAY_SIZE(xtensa_fp_flag_map); ++i) {
if (fef & xtensa_fp_flag_map[i].softfloat_fp_flag) {
flags |= xtensa_fp_flag_map[i].xtensa_fp_flag;
}
}
env->uregs[FSR] = flags << XTENSA_FSR_FLAGS_SHIFT;
return flags << XTENSA_FSR_FLAGS_SHIFT;
}
float64 HELPER(abs_d)(float64 v)
{
return float64_abs(v);
}
float32 HELPER(abs_s)(float32 v)
{
return float32_abs(v);
}
float64 HELPER(neg_d)(float64 v)
{
return float64_chs(v);
}
float32 HELPER(neg_s)(float32 v)
{
return float32_chs(v);
}
float32 HELPER(fpu2k_add_s)(CPUXtensaState *env, float32 a, float32 b)
{
return float32_add(a, b, &env->fp_status);
}
float32 HELPER(fpu2k_sub_s)(CPUXtensaState *env, float32 a, float32 b)
{
return float32_sub(a, b, &env->fp_status);
}
float32 HELPER(fpu2k_mul_s)(CPUXtensaState *env, float32 a, float32 b)
{
return float32_mul(a, b, &env->fp_status);
}
float32 HELPER(fpu2k_madd_s)(CPUXtensaState *env,
float32 a, float32 b, float32 c)
{
return float32_muladd(b, c, a, 0, &env->fp_status);
}
float32 HELPER(fpu2k_msub_s)(CPUXtensaState *env,
float32 a, float32 b, float32 c)
{
return float32_muladd(b, c, a, float_muladd_negate_product,
&env->fp_status);
}
float64 HELPER(add_d)(CPUXtensaState *env, float64 a, float64 b)
{
set_use_first_nan(true, &env->fp_status);
return float64_add(a, b, &env->fp_status);
}
float32 HELPER(add_s)(CPUXtensaState *env, float32 a, float32 b)
{
set_use_first_nan(env->config->use_first_nan, &env->fp_status);
return float32_add(a, b, &env->fp_status);
}
float64 HELPER(sub_d)(CPUXtensaState *env, float64 a, float64 b)
{
set_use_first_nan(true, &env->fp_status);
return float64_sub(a, b, &env->fp_status);
}
float32 HELPER(sub_s)(CPUXtensaState *env, float32 a, float32 b)
{
set_use_first_nan(env->config->use_first_nan, &env->fp_status);
return float32_sub(a, b, &env->fp_status);
}
float64 HELPER(mul_d)(CPUXtensaState *env, float64 a, float64 b)
{
set_use_first_nan(true, &env->fp_status);
return float64_mul(a, b, &env->fp_status);
}
float32 HELPER(mul_s)(CPUXtensaState *env, float32 a, float32 b)
{
set_use_first_nan(env->config->use_first_nan, &env->fp_status);
return float32_mul(a, b, &env->fp_status);
}
float64 HELPER(madd_d)(CPUXtensaState *env, float64 a, float64 b, float64 c)
{
set_use_first_nan(env->config->use_first_nan, &env->fp_status);
return float64_muladd(b, c, a, 0, &env->fp_status);
}
float32 HELPER(madd_s)(CPUXtensaState *env, float32 a, float32 b, float32 c)
{
set_use_first_nan(env->config->use_first_nan, &env->fp_status);
return float32_muladd(b, c, a, 0, &env->fp_status);
}
float64 HELPER(msub_d)(CPUXtensaState *env, float64 a, float64 b, float64 c)
{
set_use_first_nan(env->config->use_first_nan, &env->fp_status);
return float64_muladd(b, c, a, float_muladd_negate_product,
&env->fp_status);
}
float32 HELPER(msub_s)(CPUXtensaState *env, float32 a, float32 b, float32 c)
{
set_use_first_nan(env->config->use_first_nan, &env->fp_status);
return float32_muladd(b, c, a, float_muladd_negate_product,
&env->fp_status);
}
float64 HELPER(mkdadj_d)(CPUXtensaState *env, float64 a, float64 b)
{
set_use_first_nan(true, &env->fp_status);
return float64_div(b, a, &env->fp_status);
}
float32 HELPER(mkdadj_s)(CPUXtensaState *env, float32 a, float32 b)
{
set_use_first_nan(env->config->use_first_nan, &env->fp_status);
return float32_div(b, a, &env->fp_status);
}
float64 HELPER(mksadj_d)(CPUXtensaState *env, float64 v)
{
set_use_first_nan(true, &env->fp_status);
return float64_sqrt(v, &env->fp_status);
}
float32 HELPER(mksadj_s)(CPUXtensaState *env, float32 v)
{
set_use_first_nan(env->config->use_first_nan, &env->fp_status);
return float32_sqrt(v, &env->fp_status);
}
uint32_t HELPER(ftoi_d)(CPUXtensaState *env, float64 v,
uint32_t rounding_mode, uint32_t scale)
{
float_status fp_status = env->fp_status;
uint32_t res;
set_float_rounding_mode(rounding_mode, &fp_status);
res = float64_to_int32(float64_scalbn(v, scale, &fp_status), &fp_status);
set_float_exception_flags(get_float_exception_flags(&fp_status),
&env->fp_status);
return res;
}
uint32_t HELPER(ftoi_s)(CPUXtensaState *env, float32 v,
uint32_t rounding_mode, uint32_t scale)
{
float_status fp_status = env->fp_status;
uint32_t res;
set_float_rounding_mode(rounding_mode, &fp_status);
res = float32_to_int32(float32_scalbn(v, scale, &fp_status), &fp_status);
set_float_exception_flags(get_float_exception_flags(&fp_status),
&env->fp_status);
return res;
}
uint32_t HELPER(ftoui_d)(CPUXtensaState *env, float64 v,
uint32_t rounding_mode, uint32_t scale)
{
float_status fp_status = env->fp_status;
float64 res;
uint32_t rv;
set_float_rounding_mode(rounding_mode, &fp_status);
res = float64_scalbn(v, scale, &fp_status);
if (float64_is_neg(v) && !float64_is_any_nan(v)) {
set_float_exception_flags(float_flag_invalid, &fp_status);
rv = float64_to_int32(res, &fp_status);
} else {
rv = float64_to_uint32(res, &fp_status);
}
set_float_exception_flags(get_float_exception_flags(&fp_status),
&env->fp_status);
return rv;
}
uint32_t HELPER(ftoui_s)(CPUXtensaState *env, float32 v,
uint32_t rounding_mode, uint32_t scale)
{
float_status fp_status = env->fp_status;
float32 res;
uint32_t rv;
set_float_rounding_mode(rounding_mode, &fp_status);
res = float32_scalbn(v, scale, &fp_status);
if (float32_is_neg(v) && !float32_is_any_nan(v)) {
rv = float32_to_int32(res, &fp_status);
if (rv) {
set_float_exception_flags(float_flag_invalid, &fp_status);
}
} else {
rv = float32_to_uint32(res, &fp_status);
}
set_float_exception_flags(get_float_exception_flags(&fp_status),
&env->fp_status);
return rv;
}
float64 HELPER(itof_d)(CPUXtensaState *env, uint32_t v, uint32_t scale)
{
return float64_scalbn(int32_to_float64(v, &env->fp_status),
(int32_t)scale, &env->fp_status);
}
float32 HELPER(itof_s)(CPUXtensaState *env, uint32_t v, uint32_t scale)
{
return float32_scalbn(int32_to_float32(v, &env->fp_status),
(int32_t)scale, &env->fp_status);
}
float64 HELPER(uitof_d)(CPUXtensaState *env, uint32_t v, uint32_t scale)
{
return float64_scalbn(uint32_to_float64(v, &env->fp_status),
(int32_t)scale, &env->fp_status);
}
float32 HELPER(uitof_s)(CPUXtensaState *env, uint32_t v, uint32_t scale)
{
return float32_scalbn(uint32_to_float32(v, &env->fp_status),
(int32_t)scale, &env->fp_status);
}
float64 HELPER(cvtd_s)(CPUXtensaState *env, float32 v)
{
return float32_to_float64(v, &env->fp_status);
}
float32 HELPER(cvts_d)(CPUXtensaState *env, float64 v)
{
return float64_to_float32(v, &env->fp_status);
}
uint32_t HELPER(un_d)(CPUXtensaState *env, float64 a, float64 b)
{
return float64_unordered_quiet(a, b, &env->fp_status);
}
uint32_t HELPER(un_s)(CPUXtensaState *env, float32 a, float32 b)
{
return float32_unordered_quiet(a, b, &env->fp_status);
}
uint32_t HELPER(oeq_d)(CPUXtensaState *env, float64 a, float64 b)
{
return float64_eq_quiet(a, b, &env->fp_status);
}
uint32_t HELPER(oeq_s)(CPUXtensaState *env, float32 a, float32 b)
{
return float32_eq_quiet(a, b, &env->fp_status);
}
uint32_t HELPER(ueq_d)(CPUXtensaState *env, float64 a, float64 b)
{
FloatRelation v = float64_compare_quiet(a, b, &env->fp_status);
return v == float_relation_equal ||
v == float_relation_unordered;
}
uint32_t HELPER(ueq_s)(CPUXtensaState *env, float32 a, float32 b)
{
FloatRelation v = float32_compare_quiet(a, b, &env->fp_status);
return v == float_relation_equal ||
v == float_relation_unordered;
}
uint32_t HELPER(olt_d)(CPUXtensaState *env, float64 a, float64 b)
{
return float64_lt(a, b, &env->fp_status);
}
uint32_t HELPER(olt_s)(CPUXtensaState *env, float32 a, float32 b)
{
return float32_lt(a, b, &env->fp_status);
}
uint32_t HELPER(ult_d)(CPUXtensaState *env, float64 a, float64 b)
{
FloatRelation v = float64_compare_quiet(a, b, &env->fp_status);
return v == float_relation_less ||
v == float_relation_unordered;
}
uint32_t HELPER(ult_s)(CPUXtensaState *env, float32 a, float32 b)
{
FloatRelation v = float32_compare_quiet(a, b, &env->fp_status);
return v == float_relation_less ||
v == float_relation_unordered;
}
uint32_t HELPER(ole_d)(CPUXtensaState *env, float64 a, float64 b)
{
return float64_le(a, b, &env->fp_status);
}
uint32_t HELPER(ole_s)(CPUXtensaState *env, float32 a, float32 b)
{
return float32_le(a, b, &env->fp_status);
}
uint32_t HELPER(ule_d)(CPUXtensaState *env, float64 a, float64 b)
{
FloatRelation v = float64_compare_quiet(a, b, &env->fp_status);
return v != float_relation_greater;
}
uint32_t HELPER(ule_s)(CPUXtensaState *env, float32 a, float32 b)
{
FloatRelation v = float32_compare_quiet(a, b, &env->fp_status);
return v != float_relation_greater;
}