/*
* TriCore emulation for qemu: fpu helper.
*
* Copyright (c) 2016 Bastian Koppelmann University of Paderborn
*
* 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 2.1 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 "fpu/softfloat.h"
#define QUIET_NAN 0x7fc00000
#define ADD_NAN 0x7fc00001
#define SQRT_NAN 0x7fc00004
#define DIV_NAN 0x7fc00008
#define MUL_NAN 0x7fc00002
#define FPU_FS PSW_USB_C
#define FPU_FI PSW_USB_V
#define FPU_FV PSW_USB_SV
#define FPU_FZ PSW_USB_AV
#define FPU_FU PSW_USB_SAV
#define float32_sqrt_nan make_float32(SQRT_NAN)
#define float32_quiet_nan make_float32(QUIET_NAN)
/* we don't care about input_denormal */
static inline uint8_t f_get_excp_flags(CPUTriCoreState *env)
{
return get_float_exception_flags(&env->fp_status)
& (float_flag_invalid
| float_flag_overflow
| float_flag_underflow
| float_flag_output_denormal
| float_flag_divbyzero
| float_flag_inexact);
}
static inline float32 f_maddsub_nan_result(float32 arg1, float32 arg2,
float32 arg3, float32 result,
uint32_t muladd_negate_c)
{
uint32_t aSign, bSign, cSign;
uint32_t aExp, bExp, cExp;
if (float32_is_any_nan(arg1) || float32_is_any_nan(arg2) ||
float32_is_any_nan(arg3)) {
return QUIET_NAN;
} else if (float32_is_infinity(arg1) && float32_is_zero(arg2)) {
return MUL_NAN;
} else if (float32_is_zero(arg1) && float32_is_infinity(arg2)) {
return MUL_NAN;
} else {
aSign = arg1 >> 31;
bSign = arg2 >> 31;
cSign = arg3 >> 31;
aExp = (arg1 >> 23) & 0xff;
bExp = (arg2 >> 23) & 0xff;
cExp = (arg3 >> 23) & 0xff;
if (muladd_negate_c) {
cSign ^= 1;
}
if (((aExp == 0xff) || (bExp == 0xff)) && (cExp == 0xff)) {
if (aSign ^ bSign ^ cSign) {
return ADD_NAN;
}
}
}
return result;
}
static void f_update_psw_flags(CPUTriCoreState *env, uint8_t flags)
{
uint8_t some_excp = 0;
set_float_exception_flags(0, &env->fp_status);
if (flags & float_flag_invalid) {
env->FPU_FI = 1 << 31;
some_excp = 1;
}
if (flags & float_flag_overflow) {
env->FPU_FV = 1 << 31;
some_excp = 1;
}
if (flags & float_flag_underflow || flags & float_flag_output_denormal) {
env->FPU_FU = 1 << 31;
some_excp = 1;
}
if (flags & float_flag_divbyzero) {
env->FPU_FZ = 1 << 31;
some_excp = 1;
}
if (flags & float_flag_inexact || flags & float_flag_output_denormal) {
env->PSW |= 1 << 26;
some_excp = 1;
}
env->FPU_FS = some_excp;
}
#define FADD_SUB(op) \
uint32_t helper_f##op(CPUTriCoreState *env, uint32_t r1, uint32_t r2) \
{ \
float32 arg1 = make_float32(r1); \
float32 arg2 = make_float32(r2); \
uint32_t flags; \
float32 f_result; \
\
f_result = float32_##op(arg2, arg1, &env->fp_status); \
flags = f_get_excp_flags(env); \
if (flags) { \
/* If the output is a NaN, but the inputs aren't, \
we return a unique value. */ \
if ((flags & float_flag_invalid) \
&& !float32_is_any_nan(arg1) \
&& !float32_is_any_nan(arg2)) { \
f_result = ADD_NAN; \
} \
f_update_psw_flags(env, flags); \
} else { \
env->FPU_FS = 0; \
} \
return (uint32_t)f_result; \
}
FADD_SUB(add)
FADD_SUB(sub)
uint32_t helper_fmul(CPUTriCoreState *env, uint32_t r1, uint32_t r2)
{
uint32_t flags;
float32 arg1 = make_float32(r1);
float32 arg2 = make_float32(r2);
float32 f_result;
f_result = float32_mul(arg1, arg2, &env->fp_status);
flags = f_get_excp_flags(env);
if (flags) {
/* If the output is a NaN, but the inputs aren't,
we return a unique value. */
if ((flags & float_flag_invalid)
&& !float32_is_any_nan(arg1)
&& !float32_is_any_nan(arg2)) {
f_result = MUL_NAN;
}
f_update_psw_flags(env, flags);
} else {
env->FPU_FS = 0;
}
return (uint32_t)f_result;
}
/*
* Target TriCore QSEED.F significand Lookup Table
*
* The QSEED.F output significand depends on the least-significant
* exponent bit and the 6 most-significant significand bits.
*
* IEEE 754 float datatype
* partitioned into Sign (S), Exponent (E) and Significand (M):
*
* S E E E E E E E E M M M M M M ...
* | | |
* +------+------+-------+-------+
* | |
* for lookup table
* calculating index for
* output E output M
*
* This lookup table was extracted by analyzing QSEED output
* from the real hardware
*/
static const uint8_t target_qseed_significand_table[128] = {
253, 252, 245, 244, 239, 238, 231, 230, 225, 224, 217, 216,
211, 210, 205, 204, 201, 200, 195, 194, 189, 188, 185, 184,
179, 178, 175, 174, 169, 168, 165, 164, 161, 160, 157, 156,
153, 152, 149, 148, 145, 144, 141, 140, 137, 136, 133, 132,
131, 130, 127, 126, 123, 122, 121, 120, 117, 116, 115, 114,
111, 110, 109, 108, 103, 102, 99, 98, 93, 92, 89, 88, 83,
82, 79, 78, 75, 74, 71, 70, 67, 66, 63, 62, 59, 58, 55,
54, 53, 52, 49, 48, 45, 44, 43, 42, 39, 38, 37, 36, 33,
32, 31, 30, 27, 26, 25, 24, 23, 22, 19, 18, 17, 16, 15,
14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2
};
uint32_t helper_qseed(CPUTriCoreState *env, uint32_t r1)
{
uint32_t arg1, S, E, M, E_minus_one, m_idx;
uint32_t new_E, new_M, new_S, result;
arg1 = make_float32(r1);
/* fetch IEEE-754 fields S, E and the uppermost 6-bit of M */
S = extract32(arg1, 31, 1);
E = extract32(arg1, 23, 8);
M = extract32(arg1, 17, 6);
if (float32_is_any_nan(arg1)) {
result = float32_quiet_nan;
} else if (float32_is_zero_or_denormal(arg1)) {
if (float32_is_neg(arg1)) {
result = float32_infinity | (1 << 31);
} else {
result = float32_infinity;
}
} else if (float32_is_neg(arg1)) {
result = float32_sqrt_nan;
} else if (float32_is_infinity(arg1)) {
result = float32_zero;
} else {
E_minus_one = E - 1;
m_idx = ((E_minus_one & 1) << 6) | M;
new_S = S;
new_E = 0xBD - E_minus_one / 2;
new_M = target_qseed_significand_table[m_idx];
result = 0;
result = deposit32(result, 31, 1, new_S);
result = deposit32(result, 23, 8, new_E);
result = deposit32(result, 15, 8, new_M);
}
if (float32_is_signaling_nan(arg1, &env->fp_status)
|| result == float32_sqrt_nan) {
env->FPU_FI = 1 << 31;
env->FPU_FS = 1;
} else {
env->FPU_FS = 0;
}
return (uint32_t) result;
}
uint32_t helper_fdiv(CPUTriCoreState *env, uint32_t r1, uint32_t r2)
{
uint32_t flags;
float32 arg1 = make_float32(r1);
float32 arg2 = make_float32(r2);
float32 f_result;
f_result = float32_div(arg1, arg2 , &env->fp_status);
flags = f_get_excp_flags(env);
if (flags) {
/* If the output is a NaN, but the inputs aren't,
we return a unique value. */
if ((flags & float_flag_invalid)
&& !float32_is_any_nan(arg1)
&& !float32_is_any_nan(arg2)) {
f_result = DIV_NAN;
}
f_update_psw_flags(env, flags);
} else {
env->FPU_FS = 0;
}
return (uint32_t)f_result;
}
uint32_t helper_fmadd(CPUTriCoreState *env, uint32_t r1,
uint32_t r2, uint32_t r3)
{
uint32_t flags;
float32 arg1 = make_float32(r1);
float32 arg2 = make_float32(r2);
float32 arg3 = make_float32(r3);
float32 f_result;
f_result = float32_muladd(arg1, arg2, arg3, 0, &env->fp_status);
flags = f_get_excp_flags(env);
if (flags) {
if (flags & float_flag_invalid) {
arg1 = float32_squash_input_denormal(arg1, &env->fp_status);
arg2 = float32_squash_input_denormal(arg2, &env->fp_status);
arg3 = float32_squash_input_denormal(arg3, &env->fp_status);
f_result = f_maddsub_nan_result(arg1, arg2, arg3, f_result, 0);
}
f_update_psw_flags(env, flags);
} else {
env->FPU_FS = 0;
}
return (uint32_t)f_result;
}
uint32_t helper_fmsub(CPUTriCoreState *env, uint32_t r1,
uint32_t r2, uint32_t r3)
{
uint32_t flags;
float32 arg1 = make_float32(r1);
float32 arg2 = make_float32(r2);
float32 arg3 = make_float32(r3);
float32 f_result;
f_result = float32_muladd(arg1, arg2, arg3, float_muladd_negate_product,
&env->fp_status);
flags = f_get_excp_flags(env);
if (flags) {
if (flags & float_flag_invalid) {
arg1 = float32_squash_input_denormal(arg1, &env->fp_status);
arg2 = float32_squash_input_denormal(arg2, &env->fp_status);
arg3 = float32_squash_input_denormal(arg3, &env->fp_status);
f_result = f_maddsub_nan_result(arg1, arg2, arg3, f_result, 1);
}
f_update_psw_flags(env, flags);
} else {
env->FPU_FS = 0;
}
return (uint32_t)f_result;
}
uint32_t helper_fcmp(CPUTriCoreState *env, uint32_t r1, uint32_t r2)
{
uint32_t result, flags;
float32 arg1 = make_float32(r1);
float32 arg2 = make_float32(r2);
set_flush_inputs_to_zero(0, &env->fp_status);
result = 1 << (float32_compare_quiet(arg1, arg2, &env->fp_status) + 1);
result |= float32_is_denormal(arg1) << 4;
result |= float32_is_denormal(arg2) << 5;
flags = f_get_excp_flags(env);
if (flags) {
f_update_psw_flags(env, flags);
} else {
env->FPU_FS = 0;
}
set_flush_inputs_to_zero(1, &env->fp_status);
return result;
}
uint32_t helper_ftoi(CPUTriCoreState *env, uint32_t arg)
{
float32 f_arg = make_float32(arg);
int32_t result, flags;
result = float32_to_int32(f_arg, &env->fp_status);
flags = f_get_excp_flags(env);
if (flags) {
if (float32_is_any_nan(f_arg)) {
result = 0;
}
f_update_psw_flags(env, flags);
} else {
env->FPU_FS = 0;
}
return (uint32_t)result;
}
uint32_t helper_itof(CPUTriCoreState *env, uint32_t arg)
{
float32 f_result;
uint32_t flags;
f_result = int32_to_float32(arg, &env->fp_status);
flags = f_get_excp_flags(env);
if (flags) {
f_update_psw_flags(env, flags);
} else {
env->FPU_FS = 0;
}
return (uint32_t)f_result;
}
uint32_t helper_utof(CPUTriCoreState *env, uint32_t arg)
{
float32 f_result;
uint32_t flags;
f_result = uint32_to_float32(arg, &env->fp_status);
flags = f_get_excp_flags(env);
if (flags) {
f_update_psw_flags(env, flags);
} else {
env->FPU_FS = 0;
}
return (uint32_t)f_result;
}
uint32_t helper_ftoiz(CPUTriCoreState *env, uint32_t arg)
{
float32 f_arg = make_float32(arg);
uint32_t result;
int32_t flags;
result = float32_to_int32_round_to_zero(f_arg, &env->fp_status);
flags = f_get_excp_flags(env);
if (flags & float_flag_invalid) {
flags &= ~float_flag_inexact;
if (float32_is_any_nan(f_arg)) {
result = 0;
}
}
if (flags) {
f_update_psw_flags(env, flags);
} else {
env->FPU_FS = 0;
}
return result;
}
uint32_t helper_ftouz(CPUTriCoreState *env, uint32_t arg)
{
float32 f_arg = make_float32(arg);
uint32_t result;
int32_t flags;
result = float32_to_uint32_round_to_zero(f_arg, &env->fp_status);
flags = f_get_excp_flags(env);
if (flags & float_flag_invalid) {
flags &= ~float_flag_inexact;
if (float32_is_any_nan(f_arg)) {
result = 0;
}
} else if (float32_lt_quiet(f_arg, 0, &env->fp_status)) {
flags = float_flag_invalid;
result = 0;
}
if (flags) {
f_update_psw_flags(env, flags);
} else {
env->FPU_FS = 0;
}
return result;
}
void helper_updfl(CPUTriCoreState *env, uint32_t arg)
{
env->FPU_FS = extract32(arg, 7, 1) & extract32(arg, 15, 1);
env->FPU_FI = (extract32(arg, 6, 1) & extract32(arg, 14, 1)) << 31;
env->FPU_FV = (extract32(arg, 5, 1) & extract32(arg, 13, 1)) << 31;
env->FPU_FZ = (extract32(arg, 4, 1) & extract32(arg, 12, 1)) << 31;
env->FPU_FU = (extract32(arg, 3, 1) & extract32(arg, 11, 1)) << 31;
/* clear FX and RM */
env->PSW &= ~(extract32(arg, 10, 1) << 26);
env->PSW |= (extract32(arg, 2, 1) & extract32(arg, 10, 1)) << 26;
fpu_set_state(env);
}
