Add fmaximum, fminimum functions

C2X adds new <math.h> functions for floating-point maximum and
minimum, corresponding to the new operations that were added in IEEE
754-2019 because of concerns about the old operations not being
associative in the presence of signaling NaNs.  fmaximum and fminimum
handle NaNs like most <math.h> functions (any NaN argument means the
result is a quiet NaN).  fmaximum_num and fminimum_num handle both
quiet and signaling NaNs the way fmax and fmin handle quiet NaNs (if
one argument is a number and the other is a NaN, return the number),
but still raise "invalid" for a signaling NaN argument, making them
exceptions to the normal rule that a function with a floating-point
result raising "invalid" also returns a quiet NaN.  fmaximum_mag,
fminimum_mag, fmaximum_mag_num and fminimum_mag_num are corresponding
functions returning the argument with greatest or least absolute
value.  All these functions also treat +0 as greater than -0.  There
are also corresponding <tgmath.h> type-generic macros.

Add these functions to glibc.  The implementations use type-generic
templates based on those for fmax, fmin, fmaxmag and fminmag, and test
inputs are based on those for those functions with appropriate
adjustments to the expected results.  The RISC-V maintainers might
wish to add optimized versions of fmaximum_num and fminimum_num (for
float and double), since RISC-V (F extension version 2.2 and later)
provides instructions corresponding to those functions - though it
might be at least as useful to add architecture-independent built-in
functions to GCC and teach the RISC-V back end to expand those
functions inline, which is what you generally want for functions that
can be implemented with a single instruction.

Tested for x86_64 and x86, and with build-many-glibcs.py.

1 files changed, 48 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/nios2/libm.abilist b/sysdeps/unix/sysv/linux/nios2/libm.abilist
index df148c1..3a2b34e 100644
--- a/sysdeps/unix/sysv/linux/nios2/libm.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libm.abilist
@@ -793,5 +793,53 @@ GLIBC_2.35 f32xfmaf64 F
 GLIBC_2.35 f32xsqrtf64 F
 GLIBC_2.35 ffma F
 GLIBC_2.35 ffmal F
+GLIBC_2.35 fmaximum F
+GLIBC_2.35 fmaximum_mag F
+GLIBC_2.35 fmaximum_mag_num F
+GLIBC_2.35 fmaximum_mag_numf F
+GLIBC_2.35 fmaximum_mag_numf32 F
+GLIBC_2.35 fmaximum_mag_numf32x F
+GLIBC_2.35 fmaximum_mag_numf64 F
+GLIBC_2.35 fmaximum_mag_numl F
+GLIBC_2.35 fmaximum_magf F
+GLIBC_2.35 fmaximum_magf32 F
+GLIBC_2.35 fmaximum_magf32x F
+GLIBC_2.35 fmaximum_magf64 F
+GLIBC_2.35 fmaximum_magl F
+GLIBC_2.35 fmaximum_num F
+GLIBC_2.35 fmaximum_numf F
+GLIBC_2.35 fmaximum_numf32 F
+GLIBC_2.35 fmaximum_numf32x F
+GLIBC_2.35 fmaximum_numf64 F
+GLIBC_2.35 fmaximum_numl F
+GLIBC_2.35 fmaximumf F
+GLIBC_2.35 fmaximumf32 F
+GLIBC_2.35 fmaximumf32x F
+GLIBC_2.35 fmaximumf64 F
+GLIBC_2.35 fmaximuml F
+GLIBC_2.35 fminimum F
+GLIBC_2.35 fminimum_mag F
+GLIBC_2.35 fminimum_mag_num F
+GLIBC_2.35 fminimum_mag_numf F
+GLIBC_2.35 fminimum_mag_numf32 F
+GLIBC_2.35 fminimum_mag_numf32x F
+GLIBC_2.35 fminimum_mag_numf64 F
+GLIBC_2.35 fminimum_mag_numl F
+GLIBC_2.35 fminimum_magf F
+GLIBC_2.35 fminimum_magf32 F
+GLIBC_2.35 fminimum_magf32x F
+GLIBC_2.35 fminimum_magf64 F
+GLIBC_2.35 fminimum_magl F
+GLIBC_2.35 fminimum_num F
+GLIBC_2.35 fminimum_numf F
+GLIBC_2.35 fminimum_numf32 F
+GLIBC_2.35 fminimum_numf32x F
+GLIBC_2.35 fminimum_numf64 F
+GLIBC_2.35 fminimum_numl F
+GLIBC_2.35 fminimumf F
+GLIBC_2.35 fminimumf32 F
+GLIBC_2.35 fminimumf32x F
+GLIBC_2.35 fminimumf64 F
+GLIBC_2.35 fminimuml F
 GLIBC_2.35 fsqrt F
 GLIBC_2.35 fsqrtl F