util: Add a roundeven test.

Reviewed-by: Carl Worth <cworth@cworth.org>

src/util/Makefile.am

@@ -50,7 +50,9 @@ endif
 
 libmesautil_la_LIBADD = $(SHA1_LIBS)
 
-check_PROGRAMS = u_atomic_test
+roundeven_test_LDADD = -lm
+
+check_PROGRAMS = u_atomic_test roundeven_test
 TESTS = $(check_PROGRAMS)
 
 BUILT_SOURCES = $(MESA_UTIL_GENERATED_FILES)

src/util/roundeven_test.c

@@ -0,0 +1,140 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <math.h>
+
+#include "macros.h"
+#include "rounding.h"
+
+int main(int argc, char *argv[])
+{
+   const struct {
+      float input, expected;
+   } float_data[] = {
+      { 0.0,                  0.0 },
+      { nextafterf(0.5, 0.0), 0.0 },
+      { 0.5,                  0.0 },
+      { nextafterf(0.5, 1.0), 1.0 },
+      { 1.0,                  1.0 },
+      { nextafterf(1.5, 1.0), 1.0 },
+      { 1.5,                  2.0 },
+      { nextafterf(1.5, 2.0), 2.0 },
+      { 2.0,                  2.0 },
+      { nextafterf(2.5, 2.0), 2.0 },
+      { 2.5,                  2.0 },
+      { nextafterf(2.5, 3.0), 3.0 },
+   };
+
+   const struct {
+      double input, expected;
+   } double_data[] = {
+      { 0.0,                 0.0 },
+      { nextafter(0.5, 0.0), 0.0 },
+      { 0.5,                 0.0 },
+      { nextafter(0.5, 1.0), 1.0 },
+      { 1.0,                 1.0 },
+      { nextafter(1.5, 1.0), 1.0 },
+      { 1.5,                 2.0 },
+      { nextafter(1.5, 2.0), 2.0 },
+      { 2.0,                 2.0 },
+      { nextafter(2.5, 2.0), 2.0 },
+      { 2.5,                 2.0 },
+      { nextafter(2.5, 3.0), 3.0 },
+   };
+
+   bool failed = false;
+   int i;
+
+   for (i = 0; i < ARRAY_SIZE(float_data); i++) {
+      float output = _mesa_roundevenf(float_data[i].input);
+      if (memcmp(&float_data[i].expected, &output, sizeof(float))) {
+         fprintf(stderr, "%d float: expected %f (%a) from "
+                         "_mesa_roundevenf(%f (%a)) but got %f (%a)\n",
+                 i,
+                 float_data[i].expected,
+                 float_data[i].expected,
+                 float_data[i].input,
+                 float_data[i].input,
+                 output,
+                 output);
+         failed = true;
+      }
+   }
+
+   /* Test negated values */
+   for (i = 0; i < ARRAY_SIZE(float_data); i++) {
+      float output = _mesa_roundevenf(-float_data[i].input);
+      float negated_expected = -float_data[i].expected;
+      if (memcmp(&negated_expected, &output, sizeof(float))) {
+         fprintf(stderr, "%d float: expected %f (%a) from "
+                         "_mesa_roundevenf(%f (%a)) but got %f (%a)\n",
+                 i,
+                 negated_expected,
+                 negated_expected,
+                 -float_data[i].input,
+                 -float_data[i].input,
+                 output,
+                 output);
+         failed = true;
+      }
+   }
+
+   for (i = 0; i < ARRAY_SIZE(double_data); i++) {
+      double output = _mesa_roundeven(double_data[i].input);
+      if (memcmp(&double_data[i].expected, &output, sizeof(double))) {
+         fprintf(stderr, "%d double: expected %f (%a) from "
+                         "_mesa_roundeven(%f (%a)) but got %f (%a)\n",
+                 i,
+                 double_data[i].expected,
+                 double_data[i].expected,
+                 double_data[i].input,
+                 double_data[i].input,
+                 output,
+                 output);
+         failed = true;
+      }
+   }
+
+   /* Test negated values */
+   for (i = 0; i < ARRAY_SIZE(double_data); i++) {
+      double output = _mesa_roundeven(-double_data[i].input);
+      double negated_expected = -double_data[i].expected;
+      if (memcmp(&negated_expected, &output, sizeof(double))) {
+         fprintf(stderr, "%d double: expected %f (%a) from "
+                         "_mesa_roundeven(%f (%a)) but got %f (%a)\n",
+                 i,
+                 negated_expected,
+                 negated_expected,
+                 -double_data[i].input,
+                 -double_data[i].input,
+                 output,
+                 output);
+         failed = true;
+      }
+   }
+
+   return failed;
+}