fpu/softfloat: implement float16_squash_input_denormal

This will be required when expanding the MINMAX() macro for 16
bit/half-precision operations.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Alex Bennée 2017-07-03 14:30:06 +01:00
parent a6e0344fa0
commit 210cbd4910
2 changed files with 16 additions and 0 deletions

View File

@ -3488,6 +3488,21 @@ static float16 roundAndPackFloat16(flag zSign, int zExp,
return packFloat16(zSign, zExp, zSig >> 13);
}
/*----------------------------------------------------------------------------
| If `a' is denormal and we are in flush-to-zero mode then set the
| input-denormal exception and return zero. Otherwise just return the value.
*----------------------------------------------------------------------------*/
float16 float16_squash_input_denormal(float16 a, float_status *status)
{
if (status->flush_inputs_to_zero) {
if (extractFloat16Exp(a) == 0 && extractFloat16Frac(a) != 0) {
float_raise(float_flag_input_denormal, status);
return make_float16(float16_val(a) & 0x8000);
}
}
return a;
}
static void normalizeFloat16Subnormal(uint32_t aSig, int *zExpPtr,
uint32_t *zSigPtr)
{

View File

@ -277,6 +277,7 @@ void float_raise(uint8_t flags, float_status *status);
| If `a' is denormal and we are in flush-to-zero mode then set the
| input-denormal exception and return zero. Otherwise just return the value.
*----------------------------------------------------------------------------*/
float16 float16_squash_input_denormal(float16 a, float_status *status);
float32 float32_squash_input_denormal(float32 a, float_status *status);
float64 float64_squash_input_denormal(float64 a, float_status *status);