From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6752 invoked by alias); 20 Sep 2006 18:01:30 -0000 Received: (qmail 6673 invoked by uid 48); 20 Sep 2006 18:01:17 -0000 Date: Wed, 20 Sep 2006 18:01:00 -0000 Subject: [Bug c/29154] New: *(* ppointer++)++ = *pointer++ generates bad code X-Bugzilla-Reason: CC Message-ID: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "ansak at bigfoot dot com" Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2006-09/txt/msg01934.txt.bz2 List-Id: Overview: The following C generates bad assembler on both PowerPC and Intel, even with no optimization: *( *pDest++ )++ = *pSource++; Ripping this apart into two lines succeeds, thus: **pDest = *pSource++; *( *pDest++ )++; System Description: System: Apple OS X 10.4 (gcc 4.0.1) and Mandriva Linux 2.6.11-6mdk (downloaded and built tarballs for 4.0.1 and 4.1.1) Compiled with: gcc test-increment.c OR gcc -g test-increment.c OR gcc -save-temps test-increment.c Compiler completed with no complaints Pre-processed intermediate, test-increment.i: # 1 "test-increment.c" # 1 "" # 1 "" # 1 "test-increment.c" # 1 "/usr/include/stdio.h" 1 3 4 # 28 "/usr/include/stdio.h" 3 4 # 1 "/usr/include/features.h" 1 3 4 # 308 "/usr/include/features.h" 3 4 # 1 "/usr/include/sys/cdefs.h" 1 3 4 # 309 "/usr/include/features.h" 2 3 4 # 331 "/usr/include/features.h" 3 4 # 1 "/usr/include/gnu/stubs.h" 1 3 4 # 332 "/usr/include/features.h" 2 3 4 # 29 "/usr/include/stdio.h" 2 3 4 # 1 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stddef.h" 1 3 4 # 214 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stddef.h" 3 4 typedef unsigned int size_t; # 35 "/usr/include/stdio.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 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stddef.h" 1 3 4 # 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; # 129 "/usr/include/bits/types.h" 3 4 # 1 "/usr/include/bits/typesizes.h" 1 3 4 # 130 "/usr/include/bits/types.h" 2 3 4 __extension__ typedef __u_quad_t __dev_t; __extension__ typedef unsigned int __uid_t; __extension__ typedef unsigned int __gid_t; __extension__ typedef unsigned long int __ino_t; __extension__ typedef __u_quad_t __ino64_t; __extension__ typedef unsigned int __mode_t; __extension__ typedef unsigned int __nlink_t; __extension__ typedef long int __off_t; __extension__ typedef __quad_t __off64_t; __extension__ typedef int __pid_t; __extension__ typedef struct { int __val[2]; } __fsid_t; __extension__ typedef long int __clock_t; __extension__ typedef unsigned long int __rlim_t; __extension__ typedef __u_quad_t __rlim64_t; __extension__ typedef unsigned int __id_t; __extension__ typedef long int __time_t; __extension__ typedef unsigned int __useconds_t; __extension__ typedef long int __suseconds_t; __extension__ typedef int __daddr_t; __extension__ typedef long int __swblk_t; __extension__ typedef int __key_t; __extension__ typedef int __clockid_t; __extension__ typedef int __timer_t; __extension__ typedef long int __blksize_t; __extension__ typedef long int __blkcnt_t; __extension__ typedef __quad_t __blkcnt64_t; __extension__ typedef unsigned long int __fsblkcnt_t; __extension__ typedef __u_quad_t __fsblkcnt64_t; __extension__ typedef unsigned long int __fsfilcnt_t; __extension__ typedef __u_quad_t __fsfilcnt64_t; __extension__ typedef int __ssize_t; typedef __off64_t __loff_t; typedef __quad_t *__qaddr_t; typedef char *__caddr_t; __extension__ typedef int __intptr_t; __extension__ typedef unsigned int __socklen_t; # 37 "/usr/include/stdio.h" 2 3 4 typedef struct _IO_FILE FILE; # 62 "/usr/include/stdio.h" 3 4 typedef struct _IO_FILE __FILE; # 72 "/usr/include/stdio.h" 3 4 # 1 "/usr/include/libio.h" 1 3 4 # 32 "/usr/include/libio.h" 3 4 # 1 "/usr/include/_G_config.h" 1 3 4 # 14 "/usr/include/_G_config.h" 3 4 # 1 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stddef.h" 1 3 4 # 326 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stddef.h" 3 4 typedef long int wchar_t; # 355 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stddef.h" 3 4 typedef unsigned int wint_t; # 15 "/usr/include/_G_config.h" 2 3 4 # 24 "/usr/include/_G_config.h" 3 4 # 1 "/usr/include/wchar.h" 1 3 4 # 48 "/usr/include/wchar.h" 3 4 # 1 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stddef.h" 1 3 4 # 49 "/usr/include/wchar.h" 2 3 4 # 1 "/usr/include/bits/wchar.h" 1 3 4 # 51 "/usr/include/wchar.h" 2 3 4 # 76 "/usr/include/wchar.h" 3 4 typedef struct { int __count; union { wint_t __wch; char __wchb[4]; } __value; } __mbstate_t; # 25 "/usr/include/_G_config.h" 2 3 4 typedef struct { __off_t __pos; __mbstate_t __state; } _G_fpos_t; typedef struct { __off64_t __pos; __mbstate_t __state; } _G_fpos64_t; # 44 "/usr/include/_G_config.h" 3 4 # 1 "/usr/include/gconv.h" 1 3 4 # 28 "/usr/include/gconv.h" 3 4 # 1 "/usr/include/wchar.h" 1 3 4 # 48 "/usr/include/wchar.h" 3 4 # 1 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stddef.h" 1 3 4 # 49 "/usr/include/wchar.h" 2 3 4 # 29 "/usr/include/gconv.h" 2 3 4 # 1 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stddef.h" 1 3 4 # 32 "/usr/include/gconv.h" 2 3 4 enum { __GCONV_OK = 0, __GCONV_NOCONV, __GCONV_NODB, __GCONV_NOMEM, __GCONV_EMPTY_INPUT, __GCONV_FULL_OUTPUT, __GCONV_ILLEGAL_INPUT, __GCONV_INCOMPLETE_INPUT, __GCONV_ILLEGAL_DESCRIPTOR, __GCONV_INTERNAL_ERROR }; enum { __GCONV_IS_LAST = 0x0001, __GCONV_IGNORE_ERRORS = 0x0002 }; struct __gconv_step; struct __gconv_step_data; struct __gconv_loaded_object; struct __gconv_trans_data; typedef int (*__gconv_fct) (struct __gconv_step *, struct __gconv_step_data *, __const unsigned char **, __const unsigned char *, unsigned char **, size_t *, int, int); typedef wint_t (*__gconv_btowc_fct) (struct __gconv_step *, unsigned char); typedef int (*__gconv_init_fct) (struct __gconv_step *); typedef void (*__gconv_end_fct) (struct __gconv_step *); typedef int (*__gconv_trans_fct) (struct __gconv_step *, struct __gconv_step_data *, void *, __const unsigned char *, __const unsigned char **, __const unsigned char *, unsigned char **, size_t *); typedef int (*__gconv_trans_context_fct) (void *, __const unsigned char *, __const unsigned char *, unsigned char *, unsigned char *); typedef int (*__gconv_trans_query_fct) (__const char *, __const char ***, size_t *); typedef int (*__gconv_trans_init_fct) (void **, const char *); typedef void (*__gconv_trans_end_fct) (void *); struct __gconv_trans_data { __gconv_trans_fct __trans_fct; __gconv_trans_context_fct __trans_context_fct; __gconv_trans_end_fct __trans_end_fct; void *__data; struct __gconv_trans_data *__next; }; struct __gconv_step { struct __gconv_loaded_object *__shlib_handle; __const char *__modname; int __counter; char *__from_name; char *__to_name; __gconv_fct __fct; __gconv_btowc_fct __btowc_fct; __gconv_init_fct __init_fct; __gconv_end_fct __end_fct; int __min_needed_from; int __max_needed_from; int __min_needed_to; int __max_needed_to; int __stateful; void *__data; }; struct __gconv_step_data { unsigned char *__outbuf; unsigned char *__outbufend; int __flags; int __invocation_counter; int __internal_use; __mbstate_t *__statep; __mbstate_t __state; struct __gconv_trans_data *__trans; }; typedef struct __gconv_info { size_t __nsteps; struct __gconv_step *__steps; __extension__ struct __gconv_step_data __data []; } *__gconv_t; # 45 "/usr/include/_G_config.h" 2 3 4 typedef union { struct __gconv_info __cd; struct { struct __gconv_info __cd; struct __gconv_step_data __data; } __combined; } _G_iconv_t; typedef int _G_int16_t __attribute__ ((__mode__ (__HI__))); typedef int _G_int32_t __attribute__ ((__mode__ (__SI__))); typedef unsigned int _G_uint16_t __attribute__ ((__mode__ (__HI__))); typedef unsigned int _G_uint32_t __attribute__ ((__mode__ (__SI__))); # 33 "/usr/include/libio.h" 2 3 4 # 53 "/usr/include/libio.h" 3 4 # 1 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stdarg.h" 1 3 4 # 43 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stdarg.h" 3 4 typedef __builtin_va_list __gnuc_va_list; # 54 "/usr/include/libio.h" 2 3 4 # 166 "/usr/include/libio.h" 3 4 struct _IO_jump_t; struct _IO_FILE; # 176 "/usr/include/libio.h" 3 4 typedef void _IO_lock_t; struct _IO_marker { struct _IO_marker *_next; struct _IO_FILE *_sbuf; int _pos; # 199 "/usr/include/libio.h" 3 4 }; enum __codecvt_result { __codecvt_ok, __codecvt_partial, __codecvt_error, __codecvt_noconv }; # 267 "/usr/include/libio.h" 3 4 struct _IO_FILE { int _flags; char* _IO_read_ptr; char* _IO_read_end; char* _IO_read_base; char* _IO_write_base; char* _IO_write_ptr; char* _IO_write_end; char* _IO_buf_base; char* _IO_buf_end; char *_IO_save_base; char *_IO_backup_base; char *_IO_save_end; struct _IO_marker *_markers; struct _IO_FILE *_chain; int _fileno; int _flags2; __off_t _old_offset; unsigned short _cur_column; signed char _vtable_offset; char _shortbuf[1]; _IO_lock_t *_lock; # 315 "/usr/include/libio.h" 3 4 __off64_t _offset; void *__pad1; void *__pad2; int _mode; char _unused2[15 * sizeof (int) - 2 * sizeof (void *)]; }; typedef struct _IO_FILE _IO_FILE; struct _IO_FILE_plus; extern struct _IO_FILE_plus _IO_2_1_stdin_; extern struct _IO_FILE_plus _IO_2_1_stdout_; extern struct _IO_FILE_plus _IO_2_1_stderr_; # 354 "/usr/include/libio.h" 3 4 typedef __ssize_t __io_read_fn (void *__cookie, char *__buf, size_t __nbytes); typedef __ssize_t __io_write_fn (void *__cookie, __const char *__buf, size_t __n); typedef int __io_seek_fn (void *__cookie, __off64_t *__pos, int __w); typedef int __io_close_fn (void *__cookie); # 406 "/usr/include/libio.h" 3 4 extern int __underflow (_IO_FILE *) __attribute__ ((__nothrow__)); extern int __uflow (_IO_FILE *) __attribute__ ((__nothrow__)); extern int __overflow (_IO_FILE *, int) __attribute__ ((__nothrow__)); extern wint_t __wunderflow (_IO_FILE *) __attribute__ ((__nothrow__)); extern wint_t __wuflow (_IO_FILE *) __attribute__ ((__nothrow__)); extern wint_t __woverflow (_IO_FILE *, wint_t) __attribute__ ((__nothrow__)); # 444 "/usr/include/libio.h" 3 4 extern int _IO_getc (_IO_FILE *__fp) __attribute__ ((__nothrow__)); extern int _IO_putc (int __c, _IO_FILE *__fp) __attribute__ ((__nothrow__)); extern int _IO_feof (_IO_FILE *__fp) __attribute__ ((__nothrow__)); extern int _IO_ferror (_IO_FILE *__fp) __attribute__ ((__nothrow__)); extern int _IO_peekc_locked (_IO_FILE *__fp) __attribute__ ((__nothrow__)); extern void _IO_flockfile (_IO_FILE *) __attribute__ ((__nothrow__)); extern void _IO_funlockfile (_IO_FILE *) __attribute__ ((__nothrow__)); extern int _IO_ftrylockfile (_IO_FILE *) __attribute__ ((__nothrow__)); # 474 "/usr/include/libio.h" 3 4 extern int _IO_vfscanf (_IO_FILE * __restrict, const char * __restrict, __gnuc_va_list, int *__restrict) __attribute__ ((__nothrow__)); extern int _IO_vfprintf (_IO_FILE *__restrict, const char *__restrict, __gnuc_va_list) __attribute__ ((__nothrow__)); extern __ssize_t _IO_padn (_IO_FILE *, int, __ssize_t) __attribute__ ((__nothrow__)); extern size_t _IO_sgetn (_IO_FILE *, void *, size_t) __attribute__ ((__nothrow__)); extern __off64_t _IO_seekoff (_IO_FILE *, __off64_t, int, int) __attribute__ ((__nothrow__)); extern __off64_t _IO_seekpos (_IO_FILE *, __off64_t, int) __attribute__ ((__nothrow__)); extern void _IO_free_backup_area (_IO_FILE *) __attribute__ ((__nothrow__)); # 73 "/usr/include/stdio.h" 2 3 4 # 86 "/usr/include/stdio.h" 3 4 typedef _G_fpos_t fpos_t; # 138 "/usr/include/stdio.h" 3 4 # 1 "/usr/include/bits/stdio_lim.h" 1 3 4 # 139 "/usr/include/stdio.h" 2 3 4 extern struct _IO_FILE *stdin; extern struct _IO_FILE *stdout; extern struct _IO_FILE *stderr; extern int remove (__const char *__filename) __attribute__ ((__nothrow__)); extern int rename (__const char *__old, __const char *__new) __attribute__ ((__nothrow__)); extern FILE *tmpfile (void); # 178 "/usr/include/stdio.h" 3 4 extern char *tmpnam (char *__s) __attribute__ ((__nothrow__)); extern char *tmpnam_r (char *__s) __attribute__ ((__nothrow__)); # 196 "/usr/include/stdio.h" 3 4 extern char *tempnam (__const char *__dir, __const char *__pfx) __attribute__ ((__nothrow__)) __attribute__ ((__malloc__)); extern int fclose (FILE *__stream); extern int fflush (FILE *__stream); # 221 "/usr/include/stdio.h" 3 4 extern int fflush_unlocked (FILE *__stream); # 235 "/usr/include/stdio.h" 3 4 extern FILE *fopen (__const char *__restrict __filename, __const char *__restrict __modes); extern FILE *freopen (__const char *__restrict __filename, __const char *__restrict __modes, FILE *__restrict __stream); # 262 "/usr/include/stdio.h" 3 4 # 273 "/usr/include/stdio.h" 3 4 extern FILE *fdopen (int __fd, __const char *__modes) __attribute__ ((__nothrow__)); # 294 "/usr/include/stdio.h" 3 4 extern void setbuf (FILE *__restrict __stream, char *__restrict __buf) __attribute__ ((__nothrow__)); extern int setvbuf (FILE *__restrict __stream, char *__restrict __buf, int __modes, size_t __n) __attribute__ ((__nothrow__)); extern void setbuffer (FILE *__restrict __stream, char *__restrict __buf, size_t __size) __attribute__ ((__nothrow__)); extern void setlinebuf (FILE *__stream) __attribute__ ((__nothrow__)); extern int fprintf (FILE *__restrict __stream, __const char *__restrict __format, ...); extern int printf (__const char *__restrict __format, ...); extern int sprintf (char *__restrict __s, __const char *__restrict __format, ...) __attribute__ ((__nothrow__)); extern int vfprintf (FILE *__restrict __s, __const char *__restrict __format, __gnuc_va_list __arg); extern int vprintf (__const char *__restrict __format, __gnuc_va_list __arg); extern int vsprintf (char *__restrict __s, __const char *__restrict __format, __gnuc_va_list __arg) __attribute__ ((__nothrow__)); extern int snprintf (char *__restrict __s, size_t __maxlen, __const char *__restrict __format, ...) __attribute__ ((__nothrow__)) __attribute__ ((__format__ (__printf__, 3, 4))); extern int vsnprintf (char *__restrict __s, size_t __maxlen, __const char *__restrict __format, __gnuc_va_list __arg) __attribute__ ((__nothrow__)) __attribute__ ((__format__ (__printf__, 3, 0))); # 388 "/usr/include/stdio.h" 3 4 extern int fscanf (FILE *__restrict __stream, __const char *__restrict __format, ...); extern int scanf (__const char *__restrict __format, ...); extern int sscanf (__const char *__restrict __s, __const char *__restrict __format, ...) __attribute__ ((__nothrow__)); # 430 "/usr/include/stdio.h" 3 4 extern int fgetc (FILE *__stream); extern int getc (FILE *__stream); extern int getchar (void); # 454 "/usr/include/stdio.h" 3 4 extern int getc_unlocked (FILE *__stream); extern int getchar_unlocked (void); # 465 "/usr/include/stdio.h" 3 4 extern int fgetc_unlocked (FILE *__stream); extern int fputc (int __c, FILE *__stream); extern int putc (int __c, FILE *__stream); extern int putchar (int __c); # 498 "/usr/include/stdio.h" 3 4 extern int fputc_unlocked (int __c, FILE *__stream); extern int putc_unlocked (int __c, FILE *__stream); extern int putchar_unlocked (int __c); extern int getw (FILE *__stream); extern int putw (int __w, FILE *__stream); extern char *fgets (char *__restrict __s, int __n, FILE *__restrict __stream); extern char *gets (char *__s); # 578 "/usr/include/stdio.h" 3 4 extern int fputs (__const char *__restrict __s, FILE *__restrict __stream); extern int puts (__const char *__s); extern int ungetc (int __c, FILE *__stream); extern size_t fread (void *__restrict __ptr, size_t __size, size_t __n, FILE *__restrict __stream); extern size_t fwrite (__const void *__restrict __ptr, size_t __size, size_t __n, FILE *__restrict __s); # 631 "/usr/include/stdio.h" 3 4 extern size_t fread_unlocked (void *__restrict __ptr, size_t __size, size_t __n, FILE *__restrict __stream); extern size_t fwrite_unlocked (__const void *__restrict __ptr, size_t __size, size_t __n, FILE *__restrict __stream); extern int fseek (FILE *__stream, long int __off, int __whence); extern long int ftell (FILE *__stream); extern void rewind (FILE *__stream); # 686 "/usr/include/stdio.h" 3 4 extern int fgetpos (FILE *__restrict __stream, fpos_t *__restrict __pos); extern int fsetpos (FILE *__stream, __const fpos_t *__pos); # 709 "/usr/include/stdio.h" 3 4 # 718 "/usr/include/stdio.h" 3 4 extern void clearerr (FILE *__stream) __attribute__ ((__nothrow__)); extern int feof (FILE *__stream) __attribute__ ((__nothrow__)); extern int ferror (FILE *__stream) __attribute__ ((__nothrow__)); extern void clearerr_unlocked (FILE *__stream) __attribute__ ((__nothrow__)); extern int feof_unlocked (FILE *__stream) __attribute__ ((__nothrow__)); extern int ferror_unlocked (FILE *__stream) __attribute__ ((__nothrow__)); extern void perror (__const char *__s); # 1 "/usr/include/bits/sys_errlist.h" 1 3 4 # 27 "/usr/include/bits/sys_errlist.h" 3 4 extern int sys_nerr; extern __const char *__const sys_errlist[]; # 748 "/usr/include/stdio.h" 2 3 4 extern int fileno (FILE *__stream) __attribute__ ((__nothrow__)); extern int fileno_unlocked (FILE *__stream) __attribute__ ((__nothrow__)); # 767 "/usr/include/stdio.h" 3 4 extern FILE *popen (__const char *__command, __const char *__modes); extern int pclose (FILE *__stream); extern char *ctermid (char *__s) __attribute__ ((__nothrow__)); # 807 "/usr/include/stdio.h" 3 4 extern void flockfile (FILE *__stream) __attribute__ ((__nothrow__)); extern int ftrylockfile (FILE *__stream) __attribute__ ((__nothrow__)); extern void funlockfile (FILE *__stream) __attribute__ ((__nothrow__)); # 834 "/usr/include/stdio.h" 3 4 # 2 "test-increment.c" 2 # 1 "/usr/include/string.h" 1 3 4 # 28 "/usr/include/string.h" 3 4 # 1 "/home/akla/gcc-4.1.1-install/lib/gcc/i686-pc-linux-gnu/4.1.1/include/stddef.h" 1 3 4 # 34 "/usr/include/string.h" 2 3 4 extern void *memcpy (void *__restrict __dest, __const void *__restrict __src, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2))); extern void *memmove (void *__dest, __const void *__src, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2))); extern void *memccpy (void *__restrict __dest, __const void *__restrict __src, int __c, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2))); extern void *memset (void *__s, int __c, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1))); extern int memcmp (__const void *__s1, __const void *__s2, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); extern void *memchr (__const void *__s, int __c, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1))); # 82 "/usr/include/string.h" 3 4 extern char *strcpy (char *__restrict __dest, __const char *__restrict __src) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2))); extern char *strncpy (char *__restrict __dest, __const char *__restrict __src, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2))); extern char *strcat (char *__restrict __dest, __const char *__restrict __src) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2))); extern char *strncat (char *__restrict __dest, __const char *__restrict __src, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2))); extern int strcmp (__const char *__s1, __const char *__s2) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); extern int strncmp (__const char *__s1, __const char *__s2, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); extern int strcoll (__const char *__s1, __const char *__s2) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); extern size_t strxfrm (char *__restrict __dest, __const char *__restrict __src, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (2))); # 130 "/usr/include/string.h" 3 4 extern char *strdup (__const char *__s) __attribute__ ((__nothrow__)) __attribute__ ((__malloc__)) __attribute__ ((__nonnull__ (1))); # 165 "/usr/include/string.h" 3 4 extern char *strchr (__const char *__s, int __c) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1))); extern char *strrchr (__const char *__s, int __c) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1))); # 181 "/usr/include/string.h" 3 4 extern size_t strcspn (__const char *__s, __const char *__reject) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); extern size_t strspn (__const char *__s, __const char *__accept) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); extern char *strpbrk (__const char *__s, __const char *__accept) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); extern char *strstr (__const char *__haystack, __const char *__needle) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); extern char *strtok (char *__restrict __s, __const char *__restrict __delim) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (2))); extern char *__strtok_r (char *__restrict __s, __const char *__restrict __delim, char **__restrict __save_ptr) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (2, 3))); extern char *strtok_r (char *__restrict __s, __const char *__restrict __delim, char **__restrict __save_ptr) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (2, 3))); # 240 "/usr/include/string.h" 3 4 extern size_t strlen (__const char *__s) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1))); # 254 "/usr/include/string.h" 3 4 extern char *strerror (int __errnum) __attribute__ ((__nothrow__)); # 281 "/usr/include/string.h" 3 4 extern char *strerror_r (int __errnum, char *__buf, size_t __buflen) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (2))); extern void __bzero (void *__s, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1))); extern void bcopy (__const void *__src, void *__dest, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2))); extern void bzero (void *__s, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1))); extern int bcmp (__const void *__s1, __const void *__s2, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); extern char *index (__const char *__s, int __c) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1))); extern char *rindex (__const char *__s, int __c) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1))); extern int ffs (int __i) __attribute__ ((__nothrow__)) __attribute__ ((__const__)); # 325 "/usr/include/string.h" 3 4 extern int strcasecmp (__const char *__s1, __const char *__s2) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); extern int strncasecmp (__const char *__s1, __const char *__s2, size_t __n) __attribute__ ((__nothrow__)) __attribute__ ((__pure__)) __attribute__ ((__nonnull__ (1, 2))); # 348 "/usr/include/string.h" 3 4 extern char *strsep (char **__restrict __stringp, __const char *__restrict __delim) __attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1, 2))); # 426 "/usr/include/string.h" 3 4 # 3 "test-increment.c" 2 char source[] = "mdaceaeplsgspeciilvhcgyeeanirwl nl ligyoyn b tcifaernupletsplaeceitgaagirtrevaiinitonctengeyds....."; int main() { char destBuffer[ 1024 ]; char* dest1[ 5 ] = { destBuffer, destBuffer + 30, destBuffer + 60, destBuffer + 90, destBuffer + 120 }; strcpy( dest1[ 0 ], " " ); strcpy( dest1[ 1 ], " " ); strcpy( dest1[ 2 ], " " ); strcpy( dest1[ 3 ], " " ); strcpy( dest1[ 4 ], " " ); char* dest2[ 5 ] = { destBuffer + 200, destBuffer + 230, destBuffer + 260, destBuffer + 290, destBuffer + 320 }; strcpy( dest2[ 0 ], " " ); strcpy( dest2[ 1 ], " " ); strcpy( dest2[ 2 ], " " ); strcpy( dest2[ 3 ], " " ); strcpy( dest2[ 4 ], " " ); char* pSource = source; { char* outPtrs[ 6 ]; outPtrs[ 0 ] = dest1[ 0 ]; outPtrs[ 1 ] = dest1[ 1 ]; outPtrs[ 2 ] = dest1[ 2 ]; outPtrs[ 3 ] = dest1[ 3 ]; outPtrs[ 4 ] = dest1[ 4 ]; int nToCopy = 100 / 5; char* pReadBuf = pSource; char* pEnd = pSource + 100; char** pEndWriteBufs = outPtrs + 5; while( pReadBuf < pEnd ) { char** pWriteBuf = &outPtrs[0]; while( pWriteBuf < pEndWriteBufs ) { **pWriteBuf = *pReadBuf++; (*( pWriteBuf ++ ) )++; } } } { char* outPtrs[ 6 ]; outPtrs[ 0 ] = dest2[ 0 ]; outPtrs[ 1 ] = dest2[ 1 ]; outPtrs[ 2 ] = dest2[ 2 ]; outPtrs[ 3 ] = dest2[ 3 ]; outPtrs[ 4 ] = dest2[ 4 ]; int nToCopy = 100 / 5; char* pReadBuf = pSource; char* pEnd = pSource + 100; char** pEndWriteBufs = outPtrs + 5; while( pReadBuf < pEnd ) { char** pWriteBuf = &outPtrs[0]; while( pWriteBuf < pEndWriteBufs ) { *(*pWriteBuf++)++ = *pReadBuf++; } } } printf( "dest1 strings should equal dest2 strings. Do they?\n" ); { int i; for( i = 0; i < 5; ++i ) { printf( "dest1[%d] = %s\n", i, dest1 [ i ] ); printf( " dest2[%d] = %s\n" , i, dest2 [ i ] ); } } return 0; } Expected result: On output, dest1 and dest2 strings should both contain a matched set of mystagogical drivel. Actual result: On gcc 3.x dest1 and dest2 strings show the same drivel, on gcc 4.x they do not. -- Summary: *(* ppointer++)++ = *pointer++ generates bad code Product: gcc Version: 4.1.1 Status: UNCONFIRMED Severity: major Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: ansak at bigfoot dot com GCC build triplet: 4.1.1 GCC host triplet: 4.0.1 GCC target triplet: 4.1.1 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29154