math: avoid runtime conversions of floating-point constants

[musl] / src / linux / ppoll.c

diff --git a/src/linux/ppoll.c b/src/linux/ppoll.c
index 9e26247..e614600 100644 (file)
--- a/src/linux/ppoll.c
+++ b/src/linux/ppoll.c
@@ -1,10 +1,26 @@
 #define _GNU_SOURCE
 #include <poll.h>
 #include <signal.h>
+#include <errno.h>
 #include "syscall.h"
 
+#define IS32BIT(x) !((x)+0x80000000ULL>>32)
+#define CLAMP(x) (int)(IS32BIT(x) ? (x) : 0x7fffffffU+((0ULL+(x))>>63))
+
 int ppoll(struct pollfd *fds, nfds_t n, const struct timespec *to, const sigset_t *mask)
 {
+       time_t s = to ? to->tv_sec : 0;
+       long ns = to ? to->tv_nsec : 0;
+#ifdef SYS_ppoll_time64
+       int r = -ENOSYS;
+       if (SYS_ppoll == SYS_ppoll_time64 || !IS32BIT(s))
+               r = __syscall_cp(SYS_ppoll_time64, fds, n,
+                       to ? ((long long[]){s, ns}) : 0,
+                       mask, _NSIG/8);
+       if (SYS_ppoll == SYS_ppoll_time64 || r != -ENOSYS)
+               return __syscall_ret(r);
+       s = CLAMP(s);
+#endif
        return syscall_cp(SYS_ppoll, fds, n,
-               to ? (struct timespec []){*to} : 0, mask, _NSIG/8);
+               to ? ((long[]){s, ns}) : 0, mask, _NSIG/8);
 }