git: 4c87cff1c8c5 - releng/15.0 - libm: remainder: make sure x is zero

The branch releng/15.0 has been updated by cperciva:

URL: https://cgit.FreeBSD.org/src/commit/?id=4c87cff1c8c53f06d8d25813fa32f1cc35657897

commit 4c87cff1c8c53f06d8d25813fa32f1cc35657897
Author:     Ahmad Khalifa <vexeduxr@FreeBSD.org>
AuthorDate: 2025-10-10 09:30:52 +0000
Commit:     Colin Percival <cperciva@FreeBSD.org>
CommitDate: 2025-10-16 17:37:22 +0000

    libm: remainder: make sure x is zero
    
    Make sure the entirety of x is zero before flipping the sign bit.
    Otherwise the sign would be wrong for small values of x when x is
    negative and |n*y| > |x|
    
    Approved by:    re (cperciva)
    Reported by:    alfredo
    PR:             251091
    Reviewed by:    kargl
    MFC after:      3 days
    Differential Revision: https://reviews.freebsd.org/D53023
    
    (cherry picked from commit 25cca51ed294890d20a3c0290814cd26875db686)
    (cherry picked from commit 583e976d6d09770a6299a19603d4f0dbaa562cac)
---
 lib/msun/src/e_remainder.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/msun/src/e_remainder.c b/lib/msun/src/e_remainder.c
index a5fb7141d01a..cc6cd320073e 100644
--- a/lib/msun/src/e_remainder.c
+++ b/lib/msun/src/e_remainder.c
@@ -64,8 +64,8 @@ remainder(double x, double p)
 		if(x>=p_half) x -= p;
 	    }
 	}
-	GET_HIGH_WORD(hx,x);
-	if ((hx&0x7fffffff)==0) hx = 0;
+	EXTRACT_WORDS(hx, lx, x);
+	if (((hx&0x7fffffff)|lx) == 0) hx = 0;
 	SET_HIGH_WORD(x,hx^sx);
 	return x;
 }