Date: Tue, 20 Dec 2016 07:50:49 +0000 (UTC) From: Ed Schouten <ed@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r310320 - stable/10/lib/libc/gen Message-ID: <201612200750.uBK7onvx040780@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: ed Date: Tue Dec 20 07:50:49 2016 New Revision: 310320 URL: https://svnweb.freebsd.org/changeset/base/310320 Log: MFC r309650: Properly sign extend the result of jrand48() and mrand48(). These functions are supposed to return a value between [-2^31, 2^31). This doesn't seem to work on 64-bit systems, where we return a value between [0, 3^32). Patch up the function to use proper casts to int32_t. While there, fix some other style bugs. Modified: stable/10/lib/libc/gen/jrand48.c stable/10/lib/libc/gen/mrand48.c Directory Properties: stable/10/ (props changed) Modified: stable/10/lib/libc/gen/jrand48.c ============================================================================== --- stable/10/lib/libc/gen/jrand48.c Tue Dec 20 07:42:15 2016 (r310319) +++ stable/10/lib/libc/gen/jrand48.c Tue Dec 20 07:50:49 2016 (r310320) @@ -14,11 +14,14 @@ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); +#include <stdint.h> + #include "rand48.h" long jrand48(unsigned short xseed[3]) { + _dorand48(xseed); - return ((long) xseed[2] << 16) + (long) xseed[1]; + return ((int32_t)(((uint32_t)xseed[2] << 16) | (uint32_t)xseed[1])); } Modified: stable/10/lib/libc/gen/mrand48.c ============================================================================== --- stable/10/lib/libc/gen/mrand48.c Tue Dec 20 07:42:15 2016 (r310319) +++ stable/10/lib/libc/gen/mrand48.c Tue Dec 20 07:50:49 2016 (r310320) @@ -14,6 +14,8 @@ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); +#include <stdint.h> + #include "rand48.h" extern unsigned short _rand48_seed[3]; @@ -21,6 +23,8 @@ extern unsigned short _rand48_seed[3]; long mrand48(void) { + _dorand48(_rand48_seed); - return ((long) _rand48_seed[2] << 16) + (long) _rand48_seed[1]; + return ((int32_t)(((uint32_t)_rand48_seed[2] << 16) | + (uint32_t)_rand48_seed[1])); }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201612200750.uBK7onvx040780>