Add new testcase testing some corner-cases for expm1. Provided by Matthew Brett git-svn-id: svn+ssh://svn.code.sf.net/p/mingw-w64/code/trunk@6593 4407c894-4637-0410-b4f5-ada5f102cad1

diff --git a/mingw-w64-crt/testcases/t_expm1.c b/mingw-w64-crt/testcases/t_expm1.c
new file mode 100644
index 0000000..a623e7c
--- /dev/null
+++ b/mingw-w64-crt/testcases/t_expm1.c

@@ -0,0 +1,52 @@
+/* Test corner case for IEEE expm1
+ *
+ * http://pubs.opengroup.org/onlinepubs/9699919799/functions/expm1.html
+ *
+ */
+#ifndef __USE_MINGW_ANSI_STDIO
+#define __USE_MINGW_ANSI_STDIO 1
+#endif
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define STR_VALUE(arg) #arg
+#define MINUS_ZERO -0.
+#define N_TESTS 5
+
+int
+main ()
+{
+  int res = 0;
+
+#define TEST(func, dtype, fmt) do { \
+    int i; \
+    char fmt_str[20]; \
+    dtype input, output, exp; \
+    dtype inp_out[N_TESTS][2] = { \
+        {0, 0}, \
+        {NAN, NAN}, \
+        {MINUS_ZERO, MINUS_ZERO}, \
+        {-INFINITY, -1}, \
+        {INFINITY, INFINITY}, \
+    }; \
+    sprintf(fmt_str, "%s(%s) = %s\n", STR_VALUE(func), fmt, fmt); \
+    for (i=0; i<N_TESTS; i++) { \
+        input = inp_out[i][0]; \
+        exp = inp_out[i][1]; \
+        output = func(input); \
+        printf(fmt_str, input, output); \
+        if ((output != exp && !isnan(exp)) \
+                || (isnan(output) ^ isnan(exp))) \
+        { \
+            res |= 1; \
+            printf("which is bogus!\n"); \
+        } \
+    } \
+} while (0)
+
+  TEST (expm1, double, "%f");
+  TEST (expm1f, float, "%f");
+  TEST (expm1l, long double, "%lf");
+  return res;
+}