diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-96/x2y2m1l.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-96/x2y2m1l.c | 38 |
1 files changed, 4 insertions, 34 deletions
diff --git a/sysdeps/ieee754/ldbl-96/x2y2m1l.c b/sysdeps/ieee754/ldbl-96/x2y2m1l.c index 733742da04..392830c1b0 100644 --- a/sysdeps/ieee754/ldbl-96/x2y2m1l.c +++ b/sysdeps/ieee754/ldbl-96/x2y2m1l.c @@ -1,5 +1,5 @@ /* Compute x^2 + y^2 - 1, without large cancellation error. - Copyright (C) 2012-2016 Free Software Foundation, Inc. + Copyright (C) 2012-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -18,7 +18,7 @@ #include <math.h> #include <math_private.h> -#include <float.h> +#include <mul_splitl.h> #include <stdlib.h> /* Calculate X + Y exactly and store the result in *HI + *LO. It is @@ -33,36 +33,6 @@ add_split (long double *hi, long double *lo, long double x, long double y) *lo = (x - *hi) + y; } -/* Calculate X * Y exactly and store the result in *HI + *LO. It is - given that the values are small enough that no overflow occurs and - large enough (or zero) that no underflow occurs. */ - -static inline void -mul_split (long double *hi, long double *lo, long double x, long double y) -{ -#ifdef __FP_FAST_FMAL - /* Fast built-in fused multiply-add. */ - *hi = x * y; - *lo = __builtin_fmal (x, y, -*hi); -#elif defined FP_FAST_FMAL - /* Fast library fused multiply-add, compiler before GCC 4.6. */ - *hi = x * y; - *lo = __fmal (x, y, -*hi); -#else - /* Apply Dekker's algorithm. */ - *hi = x * y; -# define C ((1LL << (LDBL_MANT_DIG + 1) / 2) + 1) - long double x1 = x * C; - long double y1 = y * C; -# undef C - x1 = (x - x1) + x1; - y1 = (y - y1) + y1; - long double x2 = x - x1; - long double y2 = y - y1; - *lo = (((x1 * y1 - *hi) + x1 * y2) + x2 * y1) + x2 * y2; -#endif -} - /* Compare absolute values of floating-point values pointed to by P and Q for qsort. */ @@ -88,8 +58,8 @@ __x2y2m1l (long double x, long double y) { long double vals[5]; SET_RESTORE_ROUNDL (FE_TONEAREST); - mul_split (&vals[1], &vals[0], x, x); - mul_split (&vals[3], &vals[2], y, y); + mul_splitl (&vals[1], &vals[0], x, x); + mul_splitl (&vals[3], &vals[2], y, y); vals[4] = -1.0L; qsort (vals, 5, sizeof (long double), compare); /* Add up the values so that each element of VALS has absolute value |