A few simple regression tests for remainder(), remainderf(),

remquo(), and remquof().

tools/regression/lib/msun/Makefile

@@ -1,6 +1,6 @@
 # $FreeBSD$
 
-TESTS=	test-fenv test-ilogb test-lrint test-lround test-next
+TESTS=	test-fenv test-ilogb test-lrint test-lround test-next test-rem
 CFLAGS+= -O0 -lm
 ARCH!=	uname -m
 .if ${ARCH} == "alpha"

tools/regression/lib/msun/test-rem.c

@@ -0,0 +1,143 @@
+/*-
+ * Copyright (c) 2005 David Schultz <das@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Test for remainder functions: remainder, remainderf, remquo, remquof.
+ * Missing tests: fmod, fmodf.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <strings.h>
+
+static void test_invalid(double, double);
+static void testd(double, double, double, int);
+static void testf(float, float, float, int);
+
+#define	test(x, y, e_r, e_q) do {	\
+	testd(x, y, e_r, e_q);		\
+	testf(x, y, e_r, e_q);		\
+} while (0)
+
+int
+main(int argc, char *argv[])
+{
+
+	printf("1..2\n");
+
+	test_invalid(0.0, 0.0);
+	test_invalid(1.0, 0.0);
+	test_invalid(INFINITY, 0.0);
+	test_invalid(INFINITY, 1.0);
+	test_invalid(-INFINITY, 1.0);
+	test_invalid(NAN, 1.0);
+	test_invalid(1.0, NAN);
+
+	test(4, 4, 0, 1);
+	test(0, 3.0, 0, 0);
+	testd(0x1p-1074, 1, 0x1p-1074, 0x1p-1074);
+	testf(0x1p-149, 1, 0x1p-149, 0x1p-149);
+	test(3.0, 4, -1, 1);
+	test(3.0, -4, -1, -1);
+	testd(275 * 1193040, 275, 0, 1193040);
+	test(4.5 * 7.5, 4.5, -2.25, 8);	/* we should get the even one */
+	testf(0x1.9044f6p-1, 0x1.ce662ep-1, -0x1.f109cp-4, 1);
+
+	printf("ok 1 - rem\n");
+
+	/*
+	 * The actual quotient here is 864062210.50000003..., but
+	 * double-precision division gets -8.64062210.5, which rounds
+	 * the wrong way.  This test ensures that remquo() is smart
+	 * enough to get the low-order bit right.
+	 */
+	testd(-0x1.98260f22fc6dep-302, 0x1.fb3167c430a13p-332,
+	    0x1.fb3165b82de72p-333, -864062211);
+	/* Even harder cases with greater exponent separation */
+	test(0x1.fp100, 0x1.ep-40, -0x1.cp-41, 143165577);
+	testd(-0x1.abcdefp120, 0x1.87654321p-120,
+	    -0x1.69c78ec4p-121, -63816414);
+
+	printf("ok 2 - rem\n");
+
+	return (0);
+}
+
+static void
+test_invalid(double x, double y)
+{
+	int q;
+
+	q = 0xdeadbeef;
+
+	assert(isnan(remainder(x, y)));
+	assert(isnan(remquo(x, y, &q)));
+	assert(q == 0xdeadbeef);
+
+	assert(isnan(remainderf(x, y)));
+	assert(isnan(remquof(x, y, &q)));
+	assert(q == 0xdeadbeef);
+}
+
+/* 0x012345 ==> 0x01ffff */
+static inline int
+mask(int x)
+{
+	return ((unsigned)~0 >> (32 - fls(x)));
+}
+
+static void
+testd(double x, double y, double expected_rem, int expected_quo)
+{
+	int q;
+
+	q = random();
+	assert(remainder(x, y) == expected_rem);
+	assert(remquo(x, y, &q) == expected_rem);
+	assert((q & 0x7) == (expected_quo & 0x7));
+	assert((q > 0) ^ !(expected_quo > 0));
+	q = abs(q);
+	assert((q & mask(q)) == (abs(expected_quo) & mask(q)));
+}
+
+static void
+testf(float x, float y, float expected_rem, int expected_quo)
+{
+	int q;
+
+	q = random();
+	assert(remainderf(x, y) == expected_rem);
+	assert(remquof(x, y, &q) == expected_rem);
+	assert((q & 0x7) == (expected_quo & 0x7));
+	assert((q > 0) ^ !(expected_quo > 0));
+	q = abs(q);
+	assert((q & mask(q)) == (abs(expected_quo) & mask(q)));
+}