summaryrefslogtreecommitdiff
path: root/src/floatfns.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/floatfns.c')
-rw-r--r--src/floatfns.c19
1 files changed, 6 insertions, 13 deletions
diff --git a/src/floatfns.c b/src/floatfns.c
index 2eab38803d7..4492815c765 100644
--- a/src/floatfns.c
+++ b/src/floatfns.c
@@ -27,19 +27,22 @@ along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */
frexp, ldexp, log, log10 [via (log X 10)], *modf, pow, sin, *sinh,
sqrt, tan, *tanh.
- C99 and C11 require the following math.h functions in addition to
+ C99, C11 and C17 require the following math.h functions in addition to
the C89 functions. Of these, Emacs currently exports only the
starred ones to Lisp, since we haven't found a use for the others.
Also, it uses the ones marked "+" internally:
acosh, atanh, cbrt, copysign (implemented by signbit), erf, erfc,
exp2, expm1, fdim, fma, fmax, fmin, fpclassify, hypot, +ilogb,
- isfinite, isgreater, isgreaterequal, isinf, isless, islessequal,
+ +isfinite, isgreater, isgreaterequal, +isinf, isless, islessequal,
islessgreater, *isnan, isnormal, isunordered, lgamma, log1p, *log2
[via (log X 2)], logb (approximately; implemented by frexp),
+lrint/llrint, +lround/llround, nan, nearbyint, nextafter,
nexttoward, remainder, remquo, *rint, round, scalbln, +scalbn,
+signbit, tgamma, *trunc.
+ C23 requires many more math.h functions. Emacs does not yet export
+ or use them.
+
The C standard also requires functions for float and long double
that are not listed above. Of these functions, Emacs uses only the
following internally: fabsf, powf, sprintf.
@@ -52,8 +55,6 @@ along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */
#include <math.h>
-#include <count-leading-zeros.h>
-
/* Emacs needs proper handling of +/-inf; correct printing as well as
important packages depend on it. Make sure the user didn't specify
-ffinite-math-only, either directly or implicitly with -Ofast or
@@ -301,14 +302,6 @@ DEFUN ("float", Ffloat, Sfloat, 1, 1, 0,
return FLOATP (arg) ? arg : make_float (XFLOATINT (arg));
}
-static int
-ecount_leading_zeros (EMACS_UINT x)
-{
- return (EMACS_UINT_WIDTH == UINT_WIDTH ? count_leading_zeros (x)
- : EMACS_UINT_WIDTH == ULONG_WIDTH ? count_leading_zeros_l (x)
- : count_leading_zeros_ll (x));
-}
-
DEFUN ("logb", Flogb, Slogb, 1, 1, 0,
doc: /* Returns largest integer <= the base 2 log of the magnitude of ARG.
This is the same as the exponent of a float. */)
@@ -335,7 +328,7 @@ This is the same as the exponent of a float. */)
EMACS_INT i = XFIXNUM (arg);
if (i == 0)
return make_float (-HUGE_VAL);
- value = EMACS_UINT_WIDTH - 1 - ecount_leading_zeros (eabs (i));
+ value = elogb (eabs (i));
}
return make_fixnum (value);