target-sh4: implement flush-to-zero

When the FPSCR.DN bit is set, the SH4 FPU treat denormalized numbers as
zero. Enable the corresponding softfloat option when this bit is set.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Aurelien Jarno 2011-01-14 20:39:18 +01:00
parent 26ac1ea559
commit a0d4ac333a
2 changed files with 2 additions and 0 deletions

View File

@ -449,6 +449,7 @@ void helper_ld_fpscr(uint32_t val)
} else {
set_float_rounding_mode(float_round_nearest_even, &env->fp_status);
}
set_flush_to_zero((val & FPSCR_DN) != 0, &env->fp_status);
}
uint32_t helper_fabs_FT(uint32_t t0)

View File

@ -205,6 +205,7 @@ static void cpu_sh4_reset(CPUSH4State * env)
#else
env->fpscr = FPSCR_DN | FPSCR_RM_ZERO; /* CPU reset value according to SH4 manual */
set_float_rounding_mode(float_round_to_zero, &env->fp_status);
set_flush_to_zero(1, &env->fp_status);
#endif
set_default_nan_mode(1, &env->fp_status);
env->mmucr = 0;