[PATCH v6 1/3] math: Remove the SVID error handling from lgammaf/lgammaf_r

[Adhemerval Zanella Netto]

On 04/11/25 17:52, Wilco Dijkstra wrote:
> Hi Adhemerval,
> 
> @@ -161,7 +163,7 @@ __ieee754_lgammaf_r (float x, int *signgamp)
>        if (x <= 0.0f)
>          {
>            *signgamp = asuint (x) >> 31 ? -1 : 1;
> -         return 1.0f / 0.0f;
> +         return __math_divzerof (0);
> 
> OK
> 
> @@ -206,10 +208,11 @@ __ieee754_lgammaf_r (float x, int *signgamp)
>        if (ax > 0x1.afc1ap+1f)
>          {
>            if (__glibc_unlikely (x > 0x1.895f1cp+121f))
> -           return math_narrow_eval (0x1p127f * 0x1p127f);
> +           return __math_oflowf (0);
> +
> 
> OK
> 
>            /* |x|>=2**23, must be -integer */
>            if (__glibc_unlikely (x < 0.0f && ax > 0x1p+23f))
> -           return ax / 0.0f;
> +           return __math_divzerof (1);
> 
> 
> That should be __math_divzerof (0);

Ack.

> 
> 
>            double lz = as_ln (z);
>            f = (z - 0.5) * (lz - 1) + 0x1.acfe390c97d69p-2;
>            if (ax < 0x1.0p+20f)
> @@ -271,7 +274,7 @@ __ieee754_lgammaf_r (float x, int *signgamp)
>              {
>                int ni = floorf (-2 * x);
>                if ((ni & 1) == 0 && ni == -2 * x)
> -               return 1.0f / 0.0f;
> +               return __math_divzerof (1);
> 
> Same here: __math_divzerof (0);


Ack.
> 
>  
> +++ b/sysdeps/ieee754/flt-32/math_errf.c
> @@ -84,6 +84,12 @@ __math_oflowf (uint32_t sign)
>    return xflowf (sign, 0x1p97f);
>  }
>  
> +attribute_hidden float
> +__math_oflowf_value (float x)
> +{
> +  return with_errnof (x, ERANGE);
> +}
> 
> We should name it as __math_erangef like __math_edomf since that makes it
> clearer we are setting errno only.
> 

Makes sense.