[newlib-cygwin] Improve lgammaf range for very small cases

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=ec69debcb977d6395f9e91ee20133de473484e20

commit ec69debcb977d6395f9e91ee20133de473484e20
Author: Andoni Arregi <andoni.arregui@gtd-gmbh.de>
Date:   Fri Feb 11 12:16:00 2022 +0100

    Improve lgammaf range for very small cases
    
    The original cut for small arguments at |x|<2**-70 (copied from the
    double version) produces that when computing nadj we get a subnormal
    number for t*x and thus, the division of pi/subnormal will be INF and
    the logarithm of it too, which is wrong as a result for lgammaf in this
    range.
    The proposed new limit seems to be safe and has been tested to
    produce accurate results.
    (Courtesy of Andreas Jung, ESA)

Diff:
---
 newlib/libm/math/erf_lgamma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/newlib/libm/math/erf_lgamma.c b/newlib/libm/math/erf_lgamma.c
index f88f63092..84d02159b 100644
--- a/newlib/libm/math/erf_lgamma.c
+++ b/newlib/libm/math/erf_lgamma.c
@@ -168,7 +168,7 @@ static float zero=  0.0000000000e+00;
 	        *signgamp = -1;
 	    return one/(x-x);
 	}
-	if(ix<0x1c800000) {	/* |x|<2**-70, return -log(|x|) */
+	if(ix<0x30800000) {	/* |x|<2**-30, return -log(|x|) */
 	    if(hx<0) {
 	        *signgamp = -1;
 	        return -__ieee754_logf(-x);