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/*
* 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 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"
#define ADD_NAN 0x7cf00001
#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
/* 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 bool f_is_denormal(float32 arg)
{
return float32_is_zero_or_denormal(arg) && !float32_is_zero(arg);
}
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;
}
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