Use TIME_T_MAX and TIME_T_MIN in tst-mktime2.c
Commit Message
GCC 5.3 compiles
for (time_t_max = 1; 0 < time_t_max; time_t_max *= 2)
continue;
into an infinite loop with -Os. We can copy TIME_T_MAX and TIME_T_MIN
from time/mktime.c.
Tested on x86-64. OK for trunk?
H.J.
---
[BZ #19466]
* time/tst-mktime2.c (TYPE_SIGNED): New.
(TYPE_MINIMUM): Likewise.
(TYPE_MAXIMUM): Likewise.
(TIME_T_MIN): Likewise.
(TIME_T_MAX): Likewise.
(do_test): Initialize time_t_max and time_t_min with TIME_T_MAX
and TIME_T_MIN.
---
time/tst-mktime2.c | 31 +++++++++++++++++++++++++------
1 file changed, 25 insertions(+), 6 deletions(-)
Comments
On 01/14/2016 11:44 AM, H.J. Lu wrote:
> +#ifndef TIME_T_MIN
> +# define TIME_T_MIN TYPE_MINIMUM (time_t)
> +#endif
> +#ifndef TIME_T_MAX
> +# define TIME_T_MAX TYPE_MAXIMUM (time_t)
> +#endif
> +
> static time_t time_t_max;
> static time_t time_t_min;
Please get rid of the lower-case variables, and replace all uses of them
with the new (upper-case) macros.
@@ -5,6 +5,29 @@
#include <stdlib.h>
#include <unistd.h>
+/* True if the arithmetic type T is signed. */
+#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
+
+/* The maximum and minimum values for the integer type T. These
+ macros have undefined behavior if T is signed and has padding bits.
+ If this is a problem for you, please let us know how to fix it for
+ your host. */
+#define TYPE_MINIMUM(t) \
+ ((t) (! TYPE_SIGNED (t) \
+ ? (t) 0 \
+ : ~ TYPE_MAXIMUM (t)))
+#define TYPE_MAXIMUM(t) \
+ ((t) (! TYPE_SIGNED (t) \
+ ? (t) -1 \
+ : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
+
+#ifndef TIME_T_MIN
+# define TIME_T_MIN TYPE_MINIMUM (time_t)
+#endif
+#ifndef TIME_T_MAX
+# define TIME_T_MAX TYPE_MAXIMUM (time_t)
+#endif
+
static time_t time_t_max;
static time_t time_t_min;
@@ -113,12 +136,8 @@ do_test (void)
isn't worth using anyway. */
alarm (60);
- for (time_t_max = 1; 0 < time_t_max; time_t_max *= 2)
- continue;
- time_t_max--;
- if ((time_t) -1 < 0)
- for (time_t_min = -1; (time_t) (time_t_min * 2) < 0; time_t_min *= 2)
- continue;
+ time_t_max = TIME_T_MAX;
+ time_t_min = TIME_T_MIN;
delta = time_t_max / 997; /* a suitable prime number */
for (i = 0; i < N_STRINGS; i++)
{