Does clang actually generate different code with this change?
On Sun, May 29, 2016 at 9:39 AM, Andrey A. Chernov <a...@freebsd.org> wrote: > Author: ache > Date: Sun May 29 16:39:28 2016 > New Revision: 300965 > URL: https://svnweb.freebsd.org/changeset/base/300965 > > Log: > Micro optimize: C standard guarantees that right shift for unsigned value > fills left bits with zero, and we have exact 32bit unsigned value > (uint32_t), so there is no reason to add "& 0x7fffffff" here. > > MFC after: 1 week > > Modified: > head/lib/libc/stdlib/random.c > > Modified: head/lib/libc/stdlib/random.c > ============================================================================== > --- head/lib/libc/stdlib/random.c Sun May 29 16:32:56 2016 > (r300964) > +++ head/lib/libc/stdlib/random.c Sun May 29 16:39:28 2016 > (r300965) > @@ -430,7 +430,7 @@ random(void) > */ > f = fptr; r = rptr; > *f += *r; > - i = (*f >> 1) & 0x7fffffff; /* chucking least random bit > */ > + i = *f >> 1; /* chucking least random bit */ > if (++f >= end_ptr) { > f = state; > ++r; > _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
