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|

Reported by:	alfredo
PR:		251091
Reviewed by:	kargl
MFC after:	3 days
Differential Revision: https://reviews.freebsd.org/D53023

This commit is contained in:

Ahmad Khalifa

2025-10-10 12:30:52 +03:00

parent 474ae083b1

commit 25cca51ed2

1 changed files with 2 additions and 2 deletions

									
										lib/msun/src/e_remainder.c
									
		+2
		-2
	
												View File
												
				@@ -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;

				}