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, 130 insertions, 0 deletions

diff --git a/math/libm-test-fmaximum.inc b/math/libm-test-fmaximum.inc
new file mode 100644
index 0000000000..72e12c4dfa
--- /dev/null
+++ b/math/libm-test-fmaximum.inc
@@ -0,0 +1,130 @@
+/* Test fmaximum.
+   Copyright (C) 1997-2021 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include "libm-test-driver.c"
+
+static const struct test_ff_f_data fmaximum_test_data[] =
+  {
+    TEST_ff_f (fmaximum, 0, 0, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, minus_zero, minus_zero, minus_zero, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, 0, minus_zero, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, minus_zero, 0, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, min_subnorm_value, -min_subnorm_value, min_subnorm_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -min_subnorm_value, min_subnorm_value, min_subnorm_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, min_value, -min_value, min_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -min_value, min_value, min_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, max_value, -max_value, max_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -max_value, max_value, max_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, 9, 0, 9, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, 0, 9, 9, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -9, 0, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, 0, -9, 0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+
+    TEST_ff_f (fmaximum, plus_infty, 9, plus_infty, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, 0, plus_infty, plus_infty, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -9, plus_infty, plus_infty, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, plus_infty, -9, plus_infty, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+
+    TEST_ff_f (fmaximum, minus_infty, 9, 9, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, minus_infty, -9, -9, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, 9, minus_infty, 9, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -9, minus_infty, -9, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+
+    TEST_ff_f (fmaximum, 0, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, 0, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, minus_zero, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, minus_zero, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, 9, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, 9, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -9, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -9, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, 0, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, 0, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, minus_zero, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, minus_zero, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, 9, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, 9, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -9, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -9, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, qnan_value, 0, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -qnan_value, 0, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, qnan_value, minus_zero, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -qnan_value, minus_zero, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, qnan_value, 9, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -qnan_value, 9, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, qnan_value, -9, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -qnan_value, -9, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, snan_value, 0, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -snan_value, 0, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, snan_value, minus_zero, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -snan_value, minus_zero, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, snan_value, 9, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -snan_value, 9, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, snan_value, -9, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -snan_value, -9, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, plus_infty, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, plus_infty, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, minus_infty, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, minus_infty, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, plus_infty, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, plus_infty, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, minus_infty, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, minus_infty, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, qnan_value, plus_infty, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -qnan_value, plus_infty, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, qnan_value, minus_infty, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -qnan_value, minus_infty, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, snan_value, plus_infty, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -snan_value, plus_infty, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, snan_value, minus_infty, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -snan_value, minus_infty, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, qnan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, qnan_value, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -qnan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, -qnan_value, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_ff_f (fmaximum, qnan_value, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, qnan_value, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -qnan_value, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -qnan_value, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, snan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, snan_value, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -snan_value, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -snan_value, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, snan_value, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, snan_value, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -snan_value, snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_ff_f (fmaximum, -snan_value, -snan_value, qnan_value, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+  };
+
+static void
+fmaximum_test (void)
+{
+  ALL_RM_TEST (fmaximum, 1, fmaximum_test_data, RUN_TEST_LOOP_ff_f, END);
+}
+
+static void
+do_test (void)
+{
+  fmaximum_test ();
+}
+
+/*
+ * Local Variables:
+ * mode:c
+ * End:
+ */