Bug#202017: gcc-3.3: Unnecessary branching with INET/INET6 port setting
Package: gcc-3.3
Version: 1:3.3.1-0pre0
Severity: minor
The following program
--
#include <netinet/in.h>
int
main(struct sockaddr *fromp, int port)
{
const int family = fromp->sa_family;
union {
struct sockaddr_in6 in6;
struct sockaddr_in in;
} *const u = (void *)fromp;
if (family == AF_INET6)
u->in6.sin6_port = htons(port);
else
u->in.sin_port = htons(port);
return 0;
}
--
when compiled with
gcc-3.3 -S -O2
produces
--
.file "b.c"
.text
.p2align 2,,3
.globl main
.type main, @function
main:
pushl %ebp
movl %esp, %ebp
subl $8, %esp
movl 8(%ebp), %edx
andl $-16, %esp
cmpw $10, (%edx)
movl 12(%ebp), %eax
je .L9
#APP
rorw $8, %ax
#NO_APP
.L8:
movw %ax, 2(%edx)
leave
xorl %eax, %eax
ret
.p2align 2,,3
.L9:
#APP
rorw $8, %ax
#NO_APP
jmp .L8
.size main, .-main
.ident "GCC: (GNU) 3.3.1 20030626 (Debian prerelease)"
--
As you can see, the branch due to the family is unnecessary. This bug
exists in gcc272, gcc 2.95 and gcc 3.2
I've attached the preprocessed source.
-- System Information
Debian Release: testing/unstable
Kernel Version: Linux gondolin 2.4.21-2-686-smp #1 SMP Sat Jul 5 01:42:22 EST 2003 i686 GNU/Linux
Versions of the packages gcc-3.3 depends on:
ii binutils 2.14.90.0.4-0. The GNU assembler, linker and binary utiliti
ii cpp-3.3 3.3.1-0pre0 The GNU C preprocessor
ii gcc-3.3-base 3.3.1-0pre0 The GNU Compiler Collection (base package)
ii libc6 2.3.1-16 GNU C Library: Shared libraries and Timezone
ii libgcc1 3.3.1-0pre0 GCC support library
--
# 1 "b.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "b.c"
# 1 "/usr/include/netinet/in.h" 1 3 4
# 22 "/usr/include/netinet/in.h" 3 4
# 1 "/usr/include/features.h" 1 3 4
# 291 "/usr/include/features.h" 3 4
# 1 "/usr/include/sys/cdefs.h" 1 3 4
# 292 "/usr/include/features.h" 2 3 4
# 314 "/usr/include/features.h" 3 4
# 1 "/usr/include/gnu/stubs.h" 1 3 4
# 315 "/usr/include/features.h" 2 3 4
# 23 "/usr/include/netinet/in.h" 2 3 4
# 1 "/usr/include/stdint.h" 1 3 4
# 27 "/usr/include/stdint.h" 3 4
# 1 "/usr/include/bits/wchar.h" 1 3 4
# 28 "/usr/include/stdint.h" 2 3 4
# 1 "/usr/include/bits/wordsize.h" 1 3 4
# 29 "/usr/include/stdint.h" 2 3 4
# 37 "/usr/include/stdint.h" 3 4
typedef signed char int8_t;
typedef short int int16_t;
typedef int int32_t;
__extension__
typedef long long int int64_t;
typedef unsigned char uint8_t;
typedef unsigned short int uint16_t;
typedef unsigned int uint32_t;
__extension__
typedef unsigned long long int uint64_t;
typedef signed char int_least8_t;
typedef short int int_least16_t;
typedef int int_least32_t;
__extension__
typedef long long int int_least64_t;
typedef unsigned char uint_least8_t;
typedef unsigned short int uint_least16_t;
typedef unsigned int uint_least32_t;
__extension__
typedef unsigned long long int uint_least64_t;
typedef signed char int_fast8_t;
typedef int int_fast16_t;
typedef int int_fast32_t;
__extension__
typedef long long int int_fast64_t;
typedef unsigned char uint_fast8_t;
typedef unsigned int uint_fast16_t;
typedef unsigned int uint_fast32_t;
__extension__
typedef unsigned long long int uint_fast64_t;
# 126 "/usr/include/stdint.h" 3 4
typedef int intptr_t;
typedef unsigned int uintptr_t;
# 138 "/usr/include/stdint.h" 3 4
__extension__
typedef long long int intmax_t;
__extension__
typedef unsigned long long int uintmax_t;
# 24 "/usr/include/netinet/in.h" 2 3 4
# 1 "/usr/include/bits/types.h" 1 3 4
# 28 "/usr/include/bits/types.h" 3 4
# 1 "/usr/include/bits/wordsize.h" 1 3 4
# 29 "/usr/include/bits/types.h" 2 3 4
# 1 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/stddef.h" 1 3 4
# 213 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/stddef.h" 3 4
typedef unsigned int size_t;
# 32 "/usr/include/bits/types.h" 2 3 4
typedef unsigned char __u_char;
typedef unsigned short int __u_short;
typedef unsigned int __u_int;
typedef unsigned long int __u_long;
typedef signed char __int8_t;
typedef unsigned char __uint8_t;
typedef signed short int __int16_t;
typedef unsigned short int __uint16_t;
typedef signed int __int32_t;
typedef unsigned int __uint32_t;
__extension__ typedef signed long long int __int64_t;
__extension__ typedef unsigned long long int __uint64_t;
__extension__ typedef long long int __quad_t;
__extension__ typedef unsigned long long int __u_quad_t;
# 128 "/usr/include/bits/types.h" 3 4
# 1 "/usr/include/bits/typesizes.h" 1 3 4
# 129 "/usr/include/bits/types.h" 2 3 4
typedef unsigned long long int __dev_t;
typedef unsigned int __uid_t;
typedef unsigned int __gid_t;
typedef unsigned long int __ino_t;
typedef unsigned long long int __ino64_t;
typedef unsigned int __mode_t;
typedef unsigned int __nlink_t;
typedef long int __off_t;
typedef long long int __off64_t;
typedef int __pid_t;
typedef struct { int __val[2]; } __fsid_t;
typedef long int __clock_t;
typedef unsigned long int __rlim_t;
typedef unsigned long long int __rlim64_t;
typedef unsigned int __id_t;
typedef long int __time_t;
typedef unsigned int __useconds_t;
typedef long int __suseconds_t;
typedef int __daddr_t;
typedef long int __swblk_t;
typedef int __key_t;
typedef int __clockid_t;
typedef int __timer_t;
typedef long int __blksize_t;
typedef long int __blkcnt_t;
typedef long long int __blkcnt64_t;
typedef unsigned long int __fsblkcnt_t;
typedef unsigned long long int __fsblkcnt64_t;
typedef unsigned long int __fsfilcnt_t;
typedef unsigned long long int __fsfilcnt64_t;
typedef int __ssize_t;
typedef __off64_t __loff_t;
typedef __quad_t *__qaddr_t;
typedef char *__caddr_t;
typedef int __intptr_t;
typedef unsigned int __socklen_t;
# 25 "/usr/include/netinet/in.h" 2 3 4
enum
{
IPPROTO_IP = 0,
IPPROTO_HOPOPTS = 0,
IPPROTO_ICMP = 1,
IPPROTO_IGMP = 2,
IPPROTO_IPIP = 4,
IPPROTO_TCP = 6,
IPPROTO_EGP = 8,
IPPROTO_PUP = 12,
IPPROTO_UDP = 17,
IPPROTO_IDP = 22,
IPPROTO_TP = 29,
IPPROTO_IPV6 = 41,
IPPROTO_ROUTING = 43,
IPPROTO_FRAGMENT = 44,
IPPROTO_RSVP = 46,
IPPROTO_GRE = 47,
IPPROTO_ESP = 50,
IPPROTO_AH = 51,
IPPROTO_ICMPV6 = 58,
IPPROTO_NONE = 59,
IPPROTO_DSTOPTS = 60,
IPPROTO_MTP = 92,
IPPROTO_ENCAP = 98,
IPPROTO_PIM = 103,
IPPROTO_COMP = 108,
IPPROTO_RAW = 255,
IPPROTO_MAX
};
typedef uint16_t in_port_t;
enum
{
IPPORT_ECHO = 7,
IPPORT_DISCARD = 9,
IPPORT_SYSTAT = 11,
IPPORT_DAYTIME = 13,
IPPORT_NETSTAT = 15,
IPPORT_FTP = 21,
IPPORT_TELNET = 23,
IPPORT_SMTP = 25,
IPPORT_TIMESERVER = 37,
IPPORT_NAMESERVER = 42,
IPPORT_WHOIS = 43,
IPPORT_MTP = 57,
IPPORT_TFTP = 69,
IPPORT_RJE = 77,
IPPORT_FINGER = 79,
IPPORT_TTYLINK = 87,
IPPORT_SUPDUP = 95,
IPPORT_EXECSERVER = 512,
IPPORT_LOGINSERVER = 513,
IPPORT_CMDSERVER = 514,
IPPORT_EFSSERVER = 520,
IPPORT_BIFFUDP = 512,
IPPORT_WHOSERVER = 513,
IPPORT_ROUTESERVER = 520,
IPPORT_RESERVED = 1024,
IPPORT_USERRESERVED = 5000
};
typedef uint32_t in_addr_t;
struct in_addr
{
in_addr_t s_addr;
};
# 190 "/usr/include/netinet/in.h" 3 4
struct in6_addr
{
union
{
uint8_t u6_addr8[16];
uint16_t u6_addr16[8];
uint32_t u6_addr32[4];
} in6_u;
};
extern const struct in6_addr in6addr_any;
extern const struct in6_addr in6addr_loopback;
# 1 "/usr/include/bits/socket.h" 1 3 4
# 29 "/usr/include/bits/socket.h" 3 4
# 1 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/stddef.h" 1 3 4
# 30 "/usr/include/bits/socket.h" 2 3 4
# 1 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/limits.h" 1 3 4
# 11 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/limits.h" 3 4
# 1 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/syslimits.h" 1 3 4
# 1 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/limits.h" 1 3 4
# 122 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/limits.h" 3 4
# 1 "/usr/include/limits.h" 1 3 4
# 144 "/usr/include/limits.h" 3 4
# 1 "/usr/include/bits/posix1_lim.h" 1 3 4
# 126 "/usr/include/bits/posix1_lim.h" 3 4
# 1 "/usr/include/bits/local_lim.h" 1 3 4
# 36 "/usr/include/bits/local_lim.h" 3 4
# 1 "/usr/include/linux/limits.h" 1 3 4
# 37 "/usr/include/bits/local_lim.h" 2 3 4
# 127 "/usr/include/bits/posix1_lim.h" 2 3 4
# 145 "/usr/include/limits.h" 2 3 4
# 1 "/usr/include/bits/posix2_lim.h" 1 3 4
# 149 "/usr/include/limits.h" 2 3 4
# 123 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/limits.h" 2 3 4
# 8 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/syslimits.h" 2 3 4
# 12 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/limits.h" 2 3 4
# 32 "/usr/include/bits/socket.h" 2 3 4
# 1 "/usr/include/sys/types.h" 1 3 4
# 29 "/usr/include/sys/types.h" 3 4
typedef __u_char u_char;
typedef __u_short u_short;
typedef __u_int u_int;
typedef __u_long u_long;
typedef __quad_t quad_t;
typedef __u_quad_t u_quad_t;
typedef __fsid_t fsid_t;
typedef __loff_t loff_t;
typedef __ino_t ino_t;
# 62 "/usr/include/sys/types.h" 3 4
typedef __dev_t dev_t;
typedef __gid_t gid_t;
typedef __mode_t mode_t;
typedef __nlink_t nlink_t;
typedef __uid_t uid_t;
typedef __off_t off_t;
# 100 "/usr/include/sys/types.h" 3 4
typedef __pid_t pid_t;
typedef __id_t id_t;
typedef __ssize_t ssize_t;
typedef __daddr_t daddr_t;
typedef __caddr_t caddr_t;
typedef __key_t key_t;
# 133 "/usr/include/sys/types.h" 3 4
# 1 "/usr/include/time.h" 1 3 4
# 74 "/usr/include/time.h" 3 4
typedef __time_t time_t;
# 92 "/usr/include/time.h" 3 4
typedef __clockid_t clockid_t;
# 104 "/usr/include/time.h" 3 4
typedef __timer_t timer_t;
# 134 "/usr/include/sys/types.h" 2 3 4
# 147 "/usr/include/sys/types.h" 3 4
# 1 "/usr/lib/gcc-lib/i386-linux/3.3.1/include/stddef.h" 1 3 4
# 148 "/usr/include/sys/types.h" 2 3 4
typedef unsigned long int ulong;
typedef unsigned short int ushort;
typedef unsigned int uint;
# 197 "/usr/include/sys/types.h" 3 4
typedef unsigned int u_int8_t __attribute__ ((__mode__ (__QI__)));
typedef unsigned int u_int16_t __attribute__ ((__mode__ (__HI__)));
typedef unsigned int u_int32_t __attribute__ ((__mode__ (__SI__)));
typedef unsigned int u_int64_t __attribute__ ((__mode__ (__DI__)));
typedef int register_t __attribute__ ((__mode__ (__word__)));
# 213 "/usr/include/sys/types.h" 3 4
# 1 "/usr/include/endian.h" 1 3 4
# 37 "/usr/include/endian.h" 3 4
# 1 "/usr/include/bits/endian.h" 1 3 4
# 38 "/usr/include/endian.h" 2 3 4
# 214 "/usr/include/sys/types.h" 2 3 4
# 1 "/usr/include/sys/select.h" 1 3 4
# 31 "/usr/include/sys/select.h" 3 4
# 1 "/usr/include/bits/select.h" 1 3 4
# 32 "/usr/include/sys/select.h" 2 3 4
# 1 "/usr/include/bits/sigset.h" 1 3 4
# 23 "/usr/include/bits/sigset.h" 3 4
typedef int __sig_atomic_t;
typedef struct
{
unsigned long int __val[(1024 / (8 * sizeof (unsigned long int)))];
} __sigset_t;
# 35 "/usr/include/sys/select.h" 2 3 4
typedef __sigset_t sigset_t;
# 1 "/usr/include/time.h" 1 3 4
# 116 "/usr/include/time.h" 3 4
struct timespec
{
__time_t tv_sec;
long int tv_nsec;
};
# 45 "/usr/include/sys/select.h" 2 3 4
# 1 "/usr/include/bits/time.h" 1 3 4
# 67 "/usr/include/bits/time.h" 3 4
struct timeval
{
__time_t tv_sec;
__suseconds_t tv_usec;
};
# 47 "/usr/include/sys/select.h" 2 3 4
typedef __suseconds_t suseconds_t;
typedef long int __fd_mask;
# 67 "/usr/include/sys/select.h" 3 4
typedef struct
{
__fd_mask __fds_bits[1024 / (8 * sizeof (__fd_mask))];
} fd_set;
typedef __fd_mask fd_mask;
# 99 "/usr/include/sys/select.h" 3 4
extern int select (int __nfds, fd_set *__restrict __readfds,
fd_set *__restrict __writefds,
fd_set *__restrict __exceptfds,
struct timeval *__restrict __timeout) ;
# 122 "/usr/include/sys/select.h" 3 4
# 217 "/usr/include/sys/types.h" 2 3 4
# 1 "/usr/include/sys/sysmacros.h" 1 3 4
# 220 "/usr/include/sys/types.h" 2 3 4
# 231 "/usr/include/sys/types.h" 3 4
typedef __blkcnt_t blkcnt_t;
typedef __fsblkcnt_t fsblkcnt_t;
typedef __fsfilcnt_t fsfilcnt_t;
# 266 "/usr/include/sys/types.h" 3 4
# 1 "/usr/include/bits/pthreadtypes.h" 1 3 4
# 23 "/usr/include/bits/pthreadtypes.h" 3 4
# 1 "/usr/include/bits/sched.h" 1 3 4
# 83 "/usr/include/bits/sched.h" 3 4
struct __sched_param
{
int __sched_priority;
};
# 24 "/usr/include/bits/pthreadtypes.h" 2 3 4
typedef int __atomic_lock_t;
struct _pthread_fastlock
{
long int __status;
__atomic_lock_t __spinlock;
};
typedef struct _pthread_descr_struct *_pthread_descr;
typedef struct __pthread_attr_s
{
int __detachstate;
int __schedpolicy;
struct __sched_param __schedparam;
int __inheritsched;
int __scope;
size_t __guardsize;
int __stackaddr_set;
void *__stackaddr;
size_t __stacksize;
} pthread_attr_t;
typedef struct
{
struct _pthread_fastlock __c_lock;
_pthread_descr __c_waiting;
} pthread_cond_t;
typedef struct
{
int __dummy;
} pthread_condattr_t;
typedef unsigned int pthread_key_t;
typedef struct
{
int __m_reserved;
int __m_count;
_pthread_descr __m_owner;
int __m_kind;
struct _pthread_fastlock __m_lock;
} pthread_mutex_t;
typedef struct
{
int __mutexkind;
} pthread_mutexattr_t;
typedef int pthread_once_t;
# 142 "/usr/include/bits/pthreadtypes.h" 3 4
typedef unsigned long int pthread_t;
# 267 "/usr/include/sys/types.h" 2 3 4
# 33 "/usr/include/bits/socket.h" 2 3 4
typedef __socklen_t socklen_t;
enum __socket_type
{
SOCK_STREAM = 1,
SOCK_DGRAM = 2,
SOCK_RAW = 3,
SOCK_RDM = 4,
SOCK_SEQPACKET = 5,
SOCK_PACKET = 10
};
# 142 "/usr/include/bits/socket.h" 3 4
# 1 "/usr/include/bits/sockaddr.h" 1 3 4
# 29 "/usr/include/bits/sockaddr.h" 3 4
typedef unsigned short int sa_family_t;
# 143 "/usr/include/bits/socket.h" 2 3 4
struct sockaddr
{
sa_family_t sa_family;
char sa_data[14];
};
# 162 "/usr/include/bits/socket.h" 3 4
struct sockaddr_storage
{
sa_family_t ss_family;
__uint32_t __ss_align;
char __ss_padding[(128 - (2 * sizeof (__uint32_t)))];
};
enum
{
MSG_OOB = 0x01,
MSG_PEEK = 0x02,
MSG_DONTROUTE = 0x04,
MSG_CTRUNC = 0x08,
MSG_PROXY = 0x10,
MSG_TRUNC = 0x20,
MSG_DONTWAIT = 0x40,
MSG_EOR = 0x80,
MSG_WAITALL = 0x100,
MSG_FIN = 0x200,
MSG_SYN = 0x400,
MSG_CONFIRM = 0x800,
MSG_RST = 0x1000,
MSG_ERRQUEUE = 0x2000,
MSG_NOSIGNAL = 0x4000,
MSG_MORE = 0x8000
};
struct msghdr
{
void *msg_name;
socklen_t msg_namelen;
struct iovec *msg_iov;
size_t msg_iovlen;
void *msg_control;
size_t msg_controllen;
int msg_flags;
};
struct cmsghdr
{
size_t cmsg_len;
int cmsg_level;
int cmsg_type;
__extension__ unsigned char __cmsg_data [];
};
# 257 "/usr/include/bits/socket.h" 3 4
extern struct cmsghdr *__cmsg_nxthdr (struct msghdr *__mhdr,
struct cmsghdr *__cmsg) ;
# 284 "/usr/include/bits/socket.h" 3 4
enum
{
SCM_RIGHTS = 0x01,
SCM_CREDENTIALS = 0x02,
__SCM_CONNECT = 0x03
};
struct ucred
{
pid_t pid;
uid_t uid;
gid_t gid;
};
# 1 "/usr/include/asm/socket.h" 1 3 4
# 1 "/usr/include/asm/sockios.h" 1 3 4
# 5 "/usr/include/asm/socket.h" 2 3 4
# 306 "/usr/include/bits/socket.h" 2 3 4
struct linger
{
int l_onoff;
int l_linger;
};
# 213 "/usr/include/netinet/in.h" 2 3 4
struct sockaddr_in
{
sa_family_t sin_family;
in_port_t sin_port;
struct in_addr sin_addr;
unsigned char sin_zero[sizeof (struct sockaddr) -
(sizeof (unsigned short int)) -
sizeof (in_port_t) -
sizeof (struct in_addr)];
};
struct sockaddr_in6
{
sa_family_t sin6_family;
in_port_t sin6_port;
uint32_t sin6_flowinfo;
struct in6_addr sin6_addr;
uint32_t sin6_scope_id;
};
struct ipv6_mreq
{
struct in6_addr ipv6mr_multiaddr;
unsigned int ipv6mr_interface;
};
# 1 "/usr/include/bits/in.h" 1 3 4
# 66 "/usr/include/bits/in.h" 3 4
struct ip_opts
{
struct in_addr ip_dst;
char ip_opts[40];
};
struct ip_mreq
{
struct in_addr imr_multiaddr;
struct in_addr imr_interface;
};
struct ip_mreqn
{
struct in_addr imr_multiaddr;
struct in_addr imr_address;
int imr_ifindex;
};
struct in_pktinfo
{
int ipi_ifindex;
struct in_addr ipi_spec_dst;
struct in_addr ipi_addr;
};
# 251 "/usr/include/netinet/in.h" 2 3 4
# 259 "/usr/include/netinet/in.h" 3 4
extern uint32_t ntohl (uint32_t __netlong) __attribute__ ((__const__));
extern uint16_t ntohs (uint16_t __netshort)
__attribute__ ((__const__));
extern uint32_t htonl (uint32_t __hostlong)
__attribute__ ((__const__));
extern uint16_t htons (uint16_t __hostshort)
__attribute__ ((__const__));
# 1 "/usr/include/bits/byteswap.h" 1 3 4
# 271 "/usr/include/netinet/in.h" 2 3 4
# 333 "/usr/include/netinet/in.h" 3 4
extern int bindresvport (int __sockfd, struct sockaddr_in *__sock_in) ;
extern int bindresvport6 (int __sockfd, struct sockaddr_in6 *__sock_in)
;
# 361 "/usr/include/netinet/in.h" 3 4
struct in6_pktinfo
{
struct in6_addr ipi6_addr;
unsigned int ipi6_ifindex;
};
# 2 "b.c" 2
int
main(struct sockaddr *fromp, int port)
{
const int family = fromp->sa_family;
union {
struct sockaddr_in6 in6;
struct sockaddr_in in;
} *const u = (void *)fromp;
if (family == 10)
u->in6.sin6_port = htons(port);
else
u->in.sin_port = htons(port);
return 0;
}
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