From owner-svn-src-head@freebsd.org Sun May 29 13:57:07 2016 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5E1A4B5122B; Sun, 29 May 2016 13:57:07 +0000 (UTC) (envelope-from ache@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 1E9501E43; Sun, 29 May 2016 13:57:07 +0000 (UTC) (envelope-from ache@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u4TDv6oB071841; Sun, 29 May 2016 13:57:06 GMT (envelope-from ache@FreeBSD.org) Received: (from ache@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id u4TDv6No071840; Sun, 29 May 2016 13:57:06 GMT (envelope-from ache@FreeBSD.org) Message-Id: <201605291357.u4TDv6No071840@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: ache set sender to ache@FreeBSD.org using -f From: "Andrey A. Chernov" Date: Sun, 29 May 2016 13:57:06 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r300956 - head/lib/libc/stdlib X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 29 May 2016 13:57:07 -0000 Author: ache Date: Sun May 29 13:57:06 2016 New Revision: 300956 URL: https://svnweb.freebsd.org/changeset/base/300956 Log: 1) Unifdef USE_WEAK_SEEDING since it is too obsolete to support and makes reading hard. 2) Instead of doing range transformation in each and every function here, do it single time directly in do_rand(). One "mod" operation overhead is not a big deal, but the code looks nicer and possible future functions additions or PRNG change do not miss range transformations neither have unneeded ones. 3) Use POSIX argument types for visible functions (cosmetic). MFC after: 1 week Modified: head/lib/libc/stdlib/rand.c Modified: head/lib/libc/stdlib/rand.c ============================================================================== --- head/lib/libc/stdlib/rand.c Sun May 29 12:21:54 2016 (r300955) +++ head/lib/libc/stdlib/rand.c Sun May 29 13:57:06 2016 (r300956) @@ -48,14 +48,6 @@ __FBSDID("$FreeBSD$"); static int do_rand(unsigned long *ctx) { -#ifdef USE_WEAK_SEEDING -/* - * Historic implementation compatibility. - * The random sequences do not vary much with the seed, - * even with overflowing. - */ - return ((*ctx = *ctx * 1103515245 + 12345) % ((u_long)RAND_MAX + 1)); -#else /* !USE_WEAK_SEEDING */ /* * Compute x = (7^5 * x) mod (2^31 - 1) * without overflowing 31 bits: @@ -66,48 +58,34 @@ do_rand(unsigned long *ctx) */ long hi, lo, x; - /* Must be in [1, 0x7ffffffe] range at this point. */ - hi = *ctx / 127773; - lo = *ctx % 127773; + /* Transform to [1, 0x7ffffffe] range. */ + x = (*ctx % 0x7ffffffe) + 1; + hi = x / 127773; + lo = x % 127773; x = 16807 * lo - 2836 * hi; if (x < 0) x += 0x7fffffff; - *ctx = x; /* Transform to [0, 0x7ffffffd] range. */ - return (x - 1); -#endif /* !USE_WEAK_SEEDING */ + x--; + *ctx = x; + return (x); } int -rand_r(unsigned int *ctx) +rand_r(unsigned *ctx) { u_long val; int r; -#ifdef USE_WEAK_SEEDING val = *ctx; -#else - /* Transform to [1, 0x7ffffffe] range. */ - val = (*ctx % 0x7ffffffe) + 1; -#endif r = do_rand(&val); - -#ifdef USE_WEAK_SEEDING - *ctx = (unsigned int)val; -#else - *ctx = (unsigned int)(val - 1); -#endif + *ctx = (unsigned)val; return (r); } -static u_long next = -#ifdef USE_WEAK_SEEDING - 1; -#else - 2; -#endif +static u_long next = 1; int rand(void) @@ -116,13 +94,9 @@ rand(void) } void -srand(u_int seed) +srand(unsigned seed) { next = seed; -#ifndef USE_WEAK_SEEDING - /* Transform to [1, 0x7ffffffe] range. */ - next = (next % 0x7ffffffe) + 1; -#endif } @@ -144,10 +118,6 @@ sranddev(void) mib[0] = CTL_KERN; mib[1] = KERN_ARND; sysctl(mib, 2, (void *)&next, &len, NULL, 0); -#ifndef USE_WEAK_SEEDING - /* Transform to [1, 0x7ffffffe] range. */ - next = (next % 0x7ffffffe) + 1; -#endif }