Add basic regression test for modf() issue.

encouraged by deraadt and miod

3 files changed, 40 insertions, 2 deletions

diff --git a/src/regress/lib/libc/Makefile b/src/regress/lib/libc/Makefile
index 3109c0c1fd..f138f16ffd 100644
--- a/src/regress/lib/libc/Makefile
+++ b/src/regress/lib/libc/Makefile
@@ -1,8 +1,8 @@
-#       $OpenBSD: Makefile,v 1.38 2013/12/29 01:39:44 martynas Exp $
+#       $OpenBSD: Makefile,v 1.39 2014/06/07 01:46:40 tobiasu Exp $
 
 SUBDIR+= _setjmp alloca atexit basename cephes cxa-atexit db dirname env
 SUBDIR+= fmemopen fnmatch fpclassify getcap getopt_long glob
-SUBDIR+= hsearch longjmp locale malloc mkstemp netdb open_memstream 
+SUBDIR+= hsearch longjmp locale malloc mkstemp modf netdb open_memstream
 SUBDIR+= orientation popen printf
 SUBDIR+= regex setjmp setjmp-signal sigreturn sigsetjmp sprintf
 SUBDIR+= stdio_threading stpncpy strerror strtod strtol strtonum
diff --git a/src/regress/lib/libc/modf/Makefile b/src/regress/lib/libc/modf/Makefile
new file mode 100644
index 0000000000..587c595f12
--- /dev/null
+++ b/src/regress/lib/libc/modf/Makefile
@@ -0,0 +1,3 @@
+PROG=modf_test
+
+.include <bsd.regress.mk>
diff --git a/src/regress/lib/libc/modf/modf_test.c b/src/regress/lib/libc/modf/modf_test.c
new file mode 100644
index 0000000000..f732533635
--- /dev/null
+++ b/src/regress/lib/libc/modf/modf_test.c
@@ -0,0 +1,35 @@
+/* Public domain, 2014, Tobias Ulmer <tobiasu@tmux.org> */
+
+/* Test for bug introduced in 4.4BSD modf() on sparc */
+
+#include <math.h>
+
+#define BIGFLOAT (5e15) /* Number large enough to trigger the "big" case */
+
+int
+main(void)
+{
+        double f, i;
+
+        f = modf(BIGFLOAT, &i);
+        if (i != BIGFLOAT)
+                return 1;
+        if (f != 0.0)
+                return 1;
+
+        /* Repeat, maybe we were lucky */
+        f = modf(BIGFLOAT, &i);
+        if (i != BIGFLOAT)
+                return 1;
+        if (f != 0.0)
+                return 1;
+
+        /* With negative number, for good measure */
+        f = modf(-BIGFLOAT, &i);
+        if (i != -BIGFLOAT)
+                return 1;
+        if (f != 0.0)
+                return 1;
+
+        return 0;
+}