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, 20 insertions, 5 deletions

diff --git a/math/Makefile b/math/Makefile
index 8d67bff..af734d4 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -60,7 +60,10 @@ gen-libm-calls = cargF conjF cimagF crealF cabsF e_scalbF s_cacosF	  \
 		 w_exp2F w_fmodF w_hypotF w_j0F w_j1F w_jnF w_logF	  \
 		 w_log10F w_log2F w_powF w_remainderF w_scalbF		  \
 		 w_sinhF w_sqrtF					  \
-		 w_tgammaF w_lgammaF w_lgammaF_r w_expF e_exp2F
+		 w_tgammaF w_lgammaF w_lgammaF_r w_expF e_exp2F		  \
+		 s_fmaximumF s_fmaximum_magF s_fmaximum_numF		  \
+		 s_fmaximum_mag_numF s_fminimumF s_fminimum_magF	  \
+		 s_fminimum_numF s_fminimum_mag_numF
 
 libm-calls =								  \
 	e_acosF e_acoshF e_asinF e_atan2F e_atanhF e_coshF e_expF e_fmodF \
@@ -287,9 +290,11 @@ libm-test-funcs-auto = acos acosh asin asinh atan atan2 atanh cabs cacos \
 		       lgamma log log10 log1p log2 pow sin sincos sinh sqrt \
 		       tan tanh tgamma y0 y1 yn
 libm-test-funcs-noauto = canonicalize ceil cimag conj copysign cproj creal \
-			 fabs fdim floor fmax fmaxmag fmin fminmag fmod \
-			 fpclassify frexp fromfp fromfpx getpayload ilogb \
-			 iscanonical iseqsig isfinite isgreater \
+			 fabs fdim floor fmax fmaximum fmaximum_mag \
+			 fmaximum_mag_num fmaximum_num fmaxmag fmin fminimum \
+			 fminimum_mag fminimum_mag_num fminimum_num fminmag \
+			 fmod fpclassify frexp fromfp fromfpx getpayload \
+			 ilogb iscanonical iseqsig isfinite isgreater \
 			 isgreaterequal isinf isless islessequal \
 			 islessgreater isnan isnormal issignaling issubnormal \
 			 isunordered iszero llogb llrint llround logb lrint \
@@ -375,7 +380,9 @@ tgmath3-macros = atan2 cbrt ceil copysign erf erfc exp2 expm1 fdim floor \
 		 nextafter nexttoward remainder remquo rint round scalbn \
 		 scalbln tgamma trunc acos asin atan acosh asinh atanh cos \
 		 sin tan cosh sinh tanh exp log pow sqrt fabs carg cimag conj \
-		 cproj creal roundeven nextup nextdown fminmag fmaxmag llogb \
+		 cproj creal roundeven nextup nextdown fminmag fmaxmag \
+		 fmaximum fmaximum_mag fmaximum_num fmaximum_mag_num \
+		 fminimum fminimum_mag fminimum_num fminimum_mag_num llogb \
 		 fromfp fromfpx ufromfp ufromfpx scalb $(tgmath3-narrow-macros)
 tgmath3-macro-tests = $(addprefix test-tgmath3-,$(tgmath3-macros))
 tests += $(tgmath3-macro-tests)
@@ -682,8 +689,16 @@ CFLAGS-s_finite.c += -fno-builtin-finitel
 CFLAGS-s_floor.c += -fno-builtin-floorl
 CFLAGS-s_fma.c += -fno-builtin-fmal
 CFLAGS-s_fmax.c += -fno-builtin-fmaxl
+CFLAGS-s_fmaximum.c += -fno-builtin-fmaximuml
+CFLAGS-s_fmaximum_mag.c += -fno-builtin-fmaximum_magl
+CFLAGS-s_fmaximum_mag_num.c += -fno-builtin-fmaximum_mag_numl
+CFLAGS-s_fmaximum_num.c += -fno-builtin-fmaximum_numl
 CFLAGS-s_fmaxmag.c += -fno-builtin-fmaxmagl
 CFLAGS-s_fmin.c += -fno-builtin-fminl
+CFLAGS-s_fminimum.c += -fno-builtin-fminimuml
+CFLAGS-s_fminimum_mag.c += -fno-builtin-fminimum_magl
+CFLAGS-s_fminimum_mag_num.c += -fno-builtin-fminimum_mag_numl
+CFLAGS-s_fminimum_num.c += -fno-builtin-fminimum_numl
 CFLAGS-s_fminmag.c += -fno-builtin-fminmagl
 CFLAGS-w_fmod.c += -fno-builtin-fmodl
 CFLAGS-s_fmul.c += -fno-builtin-fmull