The program shows a problem where the compiler
seems to do 16-bit arithmetic on a 15-bit field.
In the program below,
None of the 'false' conditions within a 'doRead'
should be generated by the arguments passed but
when compiled with -O2 the tests yield false
but when compiled with -O work fine.
Any assistance/advice would be greatly appreciated
=====
cat bitsBug.cxx
=====
#include <stdio.h>
typedef unsigned int uint32_t;
union BugType {
struct fieldType {
uint32_t a : 15;
uint32_t b : 1;
uint32_t : 16;
} field;
uint32_t word;
};
extern bool doRead( const uint32_t count, const uint32_t size, BugType bits1,
BugType bits2 );
int main( int argc, char *argv[] )
{
uint32_t count = 0x10;
uint32_t size = 0x40;
BugType bits1, bits2;
bits1.word = 0x0030;
bits2.word = 0x8030;
if( doRead(count, size, bits1, bits2) ) {
printf( "Passed.\n" );
return 0;
}
printf( "Failed!\n" );
return 42;
}
bool doRead( const uint32_t count, const uint32_t size, BugType bits1, BugType
bits2 )
{
if( (bits1.field.a + count) >= size ) {
bits1.field.b = !bits1.field.b;
bits1.field.a -= size;
}
bits1.field.a += count;
if( bits1.field.b == bits2.field.b ) {
if( bits1.field.a > bits2.field.a ) {
return false;
}
} else {
if( bits1.field.a < bits2.field.a ) {
return false;
}
}
return true;
}
# -------------------------------------------------------------
# arm-3d-linux-gnueabi-g++ -v -save-temps -Wall -O2 bitsBug.cxx
# -------------------------------------------------------------
Using built-in specs.
Target: arm-3d-linux-gnueabi
Configured with: /homes/system/s5_eabi_tools/gcc-4.2.3/gcc-4.2.3/configure
--prefix=/opt/s5toolsl21/lx_eabi --with-gnu-as --with-gnu-ld
--with-as=/opt/s5toolsl21/lx_eabi/bin/arm-3d-linux-gnueabi-as
--with-ld=/opt/s5toolsl21/lx_eabi/bin/arm-3d-linux-gnueabi-ld
--srcdir=/homes/system/s5_eabi_tools/gcc-4.2.3/gcc-4.2.3
--with-sysroot=/opt/s5toolsl21/syslx_eabi --target=arm-3d-linux-gnueabi
--with-cpu=arm926ej-s --enable-languages=c,c++ --without-newlib
Thread model: posix
gcc version 4.2.3
/opt/s5toolsl21/lx_eabi/libexec/gcc/arm-3d-linux-gnueabi/4.2.3/cc1plus -E
-quiet -v -D_GNU_SOURCE bitsBug.cxx -mcpu=arm926ej-s -Wall -O2 -fpch-preprocess
-o bitsBug.ii
ignoring nonexistent directory "/opt/s5toolsl21/syslx_eabi/usr/local/include"
#include "..." search starts here:
#include <...> search starts here:
/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/../../../../arm-3d-linux-gnueabi/include/c++/4.2.3
/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/../../../../arm-3d-linux-gnueabi/include/c++/4.2.3/arm-3d-linux-gnueabi
/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/../../../../arm-3d-linux-gnueabi/include/c++/4.2.3/backward
/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/include
/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/../../../../arm-3d-linux-gnueabi/include
/opt/s5toolsl21/syslx_eabi/usr/include
End of search list.
/opt/s5toolsl21/lx_eabi/libexec/gcc/arm-3d-linux-gnueabi/4.2.3/cc1plus
-fpreprocessed bitsBug.ii -quiet -dumpbase bitsBug.cxx -mcpu=arm926ej-s
-auxbase bitsBug -O2 -Wall -version -o bitsBug.s
GNU C++ version 4.2.3 (arm-3d-linux-gnueabi)
compiled by GNU C version 4.2.3.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 929c2a5646bf300132f7a0467b753b75
/opt/s5toolsl21/lx_eabi/bin/arm-3d-linux-gnueabi-as -mcpu=arm926ej-s -meabi=4
-o bitsBug.o bitsBug.s
/opt/s5toolsl21/lx_eabi/libexec/gcc/arm-3d-linux-gnueabi/4.2.3/collect2
--sysroot=/opt/s5toolsl21/syslx_eabi --eh-frame-hdr -dynamic-linker
/lib/ld-linux.so.3 -X -m armelf_linux_eabi
/opt/s5toolsl21/syslx_eabi/usr/lib/crt1.o
/opt/s5toolsl21/syslx_eabi/usr/lib/crti.o
/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/crtbegin.o
-L/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3
-L/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/../../../../arm-3d-linux-gnueabi/lib
-L/opt/s5toolsl21/syslx_eabi/lib -L/opt/s5toolsl21/syslx_eabi/usr/lib bitsBug.o
-lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc
/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/crtend.o
/opt/s5toolsl21/syslx_eabi/usr/lib/crtn.o
#-------------------------------------------------------------
#arm-3d-linux-gnueabi-g++ -v -save-temps -Wall -O2 bitsBug.cxx
#cat bitsBug.ii
#-------------------------------------------------------------
# 1 "bitsBug.cxx"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "bitsBug.cxx"
# 23 "bitsBug.cxx"
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 1 3 4
# 28 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/features.h" 1 3 4
# 330 "/opt/s5toolsl21/syslx_eabi/usr/include/features.h" 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/sys/cdefs.h" 1 3 4
# 348 "/opt/s5toolsl21/syslx_eabi/usr/include/sys/cdefs.h" 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/bits/wordsize.h" 1 3 4
# 349 "/opt/s5toolsl21/syslx_eabi/usr/include/sys/cdefs.h" 2 3 4
# 331 "/opt/s5toolsl21/syslx_eabi/usr/include/features.h" 2 3 4
# 354 "/opt/s5toolsl21/syslx_eabi/usr/include/features.h" 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/gnu/stubs.h" 1 3 4
# 355 "/opt/s5toolsl21/syslx_eabi/usr/include/features.h" 2 3 4
# 29 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 2 3 4
extern "C" {
# 1
"/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/include/stddef.h" 1
3 4
# 214
"/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/include/stddef.h" 3
4
typedef unsigned int size_t;
# 35 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 2 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/bits/types.h" 1 3 4
# 28 "/opt/s5toolsl21/syslx_eabi/usr/include/bits/types.h" 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/bits/wordsize.h" 1 3 4
# 29 "/opt/s5toolsl21/syslx_eabi/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;
# 131 "/opt/s5toolsl21/syslx_eabi/usr/include/bits/types.h" 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/bits/typesizes.h" 1 3 4
# 132 "/opt/s5toolsl21/syslx_eabi/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 void * __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 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 2 3 4
# 45 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
struct _IO_FILE;
typedef struct _IO_FILE FILE;
# 65 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
typedef struct _IO_FILE __FILE;
# 75 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 1 3 4
# 32 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/_G_config.h" 1 3 4
# 15 "/opt/s5toolsl21/syslx_eabi/usr/include/_G_config.h" 3 4
# 1
"/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/include/stddef.h" 1
3 4
# 16 "/opt/s5toolsl21/syslx_eabi/usr/include/_G_config.h" 2 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/wchar.h" 1 3 4
# 78 "/opt/s5toolsl21/syslx_eabi/usr/include/wchar.h" 3 4
typedef struct
{
int __count;
union
{
unsigned int __wch;
char __wchb[4];
} __value;
} __mbstate_t;
# 21 "/opt/s5toolsl21/syslx_eabi/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;
# 53 "/opt/s5toolsl21/syslx_eabi/usr/include/_G_config.h" 3 4
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 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 2 3 4
# 53 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 3 4
# 1
"/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/include/stdarg.h" 1
3 4
# 43
"/opt/s5toolsl21/lx_eabi/lib/gcc/arm-3d-linux-gnueabi/4.2.3/include/stdarg.h" 3
4
typedef __builtin_va_list __gnuc_va_list;
# 54 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 2 3 4
# 170 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 3 4
struct _IO_jump_t; struct _IO_FILE;
# 180 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 3 4
typedef void _IO_lock_t;
struct _IO_marker {
struct _IO_marker *_next;
struct _IO_FILE *_sbuf;
int _pos;
# 203 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 3 4
};
enum __codecvt_result
{
__codecvt_ok,
__codecvt_partial,
__codecvt_error,
__codecvt_noconv
};
# 271 "/opt/s5toolsl21/syslx_eabi/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;
# 319 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 3 4
__off64_t _offset;
# 328 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 3 4
void *__pad1;
void *__pad2;
void *__pad3;
void *__pad4;
size_t __pad5;
int _mode;
char _unused2[15 * sizeof (int) - 4 * sizeof (void *) - sizeof (size_t)];
};
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_;
# 364 "/opt/s5toolsl21/syslx_eabi/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);
typedef __io_read_fn cookie_read_function_t;
typedef __io_write_fn cookie_write_function_t;
typedef __io_seek_fn cookie_seek_function_t;
typedef __io_close_fn cookie_close_function_t;
typedef struct
{
__io_read_fn *read;
__io_write_fn *write;
__io_seek_fn *seek;
__io_close_fn *close;
} _IO_cookie_io_functions_t;
typedef _IO_cookie_io_functions_t cookie_io_functions_t;
struct _IO_cookie_file;
extern void _IO_cookie_init (struct _IO_cookie_file *__cfile, int __read_write,
void *__cookie, _IO_cookie_io_functions_t __fns);
extern "C" {
extern int __underflow (_IO_FILE *);
extern int __uflow (_IO_FILE *);
extern int __overflow (_IO_FILE *, int);
# 458 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 3 4
extern int _IO_getc (_IO_FILE *__fp);
extern int _IO_putc (int __c, _IO_FILE *__fp);
extern int _IO_feof (_IO_FILE *__fp) throw ();
extern int _IO_ferror (_IO_FILE *__fp) throw ();
extern int _IO_peekc_locked (_IO_FILE *__fp);
extern void _IO_flockfile (_IO_FILE *) throw ();
extern void _IO_funlockfile (_IO_FILE *) throw ();
extern int _IO_ftrylockfile (_IO_FILE *) throw ();
# 488 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 3 4
extern int _IO_vfscanf (_IO_FILE * __restrict, const char * __restrict,
__gnuc_va_list, int *__restrict);
extern int _IO_vfprintf (_IO_FILE *__restrict, const char *__restrict,
__gnuc_va_list);
extern __ssize_t _IO_padn (_IO_FILE *, int, __ssize_t);
extern size_t _IO_sgetn (_IO_FILE *, void *, size_t);
extern __off64_t _IO_seekoff (_IO_FILE *, __off64_t, int, int);
extern __off64_t _IO_seekpos (_IO_FILE *, __off64_t, int);
extern void _IO_free_backup_area (_IO_FILE *) throw ();
# 550 "/opt/s5toolsl21/syslx_eabi/usr/include/libio.h" 3 4
}
# 76 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 2 3 4
typedef __gnuc_va_list va_list;
# 89 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
typedef _G_fpos_t fpos_t;
typedef _G_fpos64_t fpos64_t;
# 141 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/bits/stdio_lim.h" 1 3 4
# 142 "/opt/s5toolsl21/syslx_eabi/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) throw ();
extern int rename (__const char *__old, __const char *__new) throw ();
extern int renameat (int __oldfd, __const char *__old, int __newfd,
__const char *__new) throw ();
extern FILE *tmpfile (void) ;
# 182 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern FILE *tmpfile64 (void) ;
extern char *tmpnam (char *__s) throw () ;
extern char *tmpnam_r (char *__s) throw () ;
# 204 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern char *tempnam (__const char *__dir, __const char *__pfx)
throw () __attribute__ ((__malloc__)) ;
extern int fclose (FILE *__stream);
extern int fflush (FILE *__stream);
# 229 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern int fflush_unlocked (FILE *__stream);
# 239 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern int fcloseall (void);
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) ;
# 272 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern FILE *fopen64 (__const char *__restrict __filename,
__const char *__restrict __modes) ;
extern FILE *freopen64 (__const char *__restrict __filename,
__const char *__restrict __modes,
FILE *__restrict __stream) ;
extern FILE *fdopen (int __fd, __const char *__modes) throw () ;
extern FILE *fopencookie (void *__restrict __magic_cookie,
__const char *__restrict __modes,
_IO_cookie_io_functions_t __io_funcs) throw () ;
extern FILE *fmemopen (void *__s, size_t __len, __const char *__modes)
throw () ;
extern FILE *open_memstream (char **__bufloc, size_t *__sizeloc) throw () ;
extern void setbuf (FILE *__restrict __stream, char *__restrict __buf) throw
();
extern int setvbuf (FILE *__restrict __stream, char *__restrict __buf,
int __modes, size_t __n) throw ();
extern void setbuffer (FILE *__restrict __stream, char *__restrict __buf,
size_t __size) throw ();
extern void setlinebuf (FILE *__stream) throw ();
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, ...) throw ();
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) throw ();
extern int snprintf (char *__restrict __s, size_t __maxlen,
__const char *__restrict __format, ...)
throw () __attribute__ ((__format__ (__printf__, 3, 4)));
extern int vsnprintf (char *__restrict __s, size_t __maxlen,
__const char *__restrict __format, __gnuc_va_list __arg)
throw () __attribute__ ((__format__ (__printf__, 3, 0)));
extern int vasprintf (char **__restrict __ptr, __const char *__restrict __f,
__gnuc_va_list __arg)
throw () __attribute__ ((__format__ (__printf__, 2, 0))) ;
extern int __asprintf (char **__restrict __ptr,
__const char *__restrict __fmt, ...)
throw () __attribute__ ((__format__ (__printf__, 2, 3))) ;
extern int asprintf (char **__restrict __ptr,
__const char *__restrict __fmt, ...)
throw () __attribute__ ((__format__ (__printf__, 2, 3))) ;
extern int vdprintf (int __fd, __const char *__restrict __fmt,
__gnuc_va_list __arg)
__attribute__ ((__format__ (__printf__, 2, 0)));
extern int dprintf (int __fd, __const char *__restrict __fmt, ...)
__attribute__ ((__format__ (__printf__, 2, 3)));
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, ...) throw ();
# 441 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern int vfscanf (FILE *__restrict __s, __const char *__restrict __format,
__gnuc_va_list __arg)
__attribute__ ((__format__ (__scanf__, 2, 0))) ;
extern int vscanf (__const char *__restrict __format, __gnuc_va_list __arg)
__attribute__ ((__format__ (__scanf__, 1, 0))) ;
extern int vsscanf (__const char *__restrict __s,
__const char *__restrict __format, __gnuc_va_list __arg)
throw () __attribute__ ((__format__ (__scanf__, 2, 0)));
# 500 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern int fgetc (FILE *__stream);
extern int getc (FILE *__stream);
extern int getchar (void);
# 528 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern int getc_unlocked (FILE *__stream);
extern int getchar_unlocked (void);
# 539 "/opt/s5toolsl21/syslx_eabi/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);
# 572 "/opt/s5toolsl21/syslx_eabi/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) ;
# 618 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern char *fgets_unlocked (char *__restrict __s, int __n,
FILE *__restrict __stream) ;
# 634 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern __ssize_t __getdelim (char **__restrict __lineptr,
size_t *__restrict __n, int __delimiter,
FILE *__restrict __stream) ;
extern __ssize_t getdelim (char **__restrict __lineptr,
size_t *__restrict __n, int __delimiter,
FILE *__restrict __stream) ;
extern __ssize_t getline (char **__restrict __lineptr,
size_t *__restrict __n,
FILE *__restrict __stream) ;
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) ;
# 695 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern int fputs_unlocked (__const char *__restrict __s,
FILE *__restrict __stream);
# 706 "/opt/s5toolsl21/syslx_eabi/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);
# 742 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern int fseeko (FILE *__stream, __off_t __off, int __whence);
extern __off_t ftello (FILE *__stream) ;
# 761 "/opt/s5toolsl21/syslx_eabi/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);
# 784 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
extern int fseeko64 (FILE *__stream, __off64_t __off, int __whence);
extern __off64_t ftello64 (FILE *__stream) ;
extern int fgetpos64 (FILE *__restrict __stream, fpos64_t *__restrict __pos);
extern int fsetpos64 (FILE *__stream, __const fpos64_t *__pos);
extern void clearerr (FILE *__stream) throw ();
extern int feof (FILE *__stream) throw () ;
extern int ferror (FILE *__stream) throw () ;
extern void clearerr_unlocked (FILE *__stream) throw ();
extern int feof_unlocked (FILE *__stream) throw () ;
extern int ferror_unlocked (FILE *__stream) throw () ;
extern void perror (__const char *__s);
# 1 "/opt/s5toolsl21/syslx_eabi/usr/include/bits/sys_errlist.h" 1 3 4
# 27 "/opt/s5toolsl21/syslx_eabi/usr/include/bits/sys_errlist.h" 3 4
extern int sys_nerr;
extern __const char *__const sys_errlist[];
extern int _sys_nerr;
extern __const char *__const _sys_errlist[];
# 823 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 2 3 4
extern int fileno (FILE *__stream) throw () ;
extern int fileno_unlocked (FILE *__stream) throw () ;
# 842 "/opt/s5toolsl21/syslx_eabi/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) throw ();
extern char *cuserid (char *__s);
struct obstack;
extern int obstack_printf (struct obstack *__restrict __obstack,
__const char *__restrict __format, ...)
throw () __attribute__ ((__format__ (__printf__, 2, 3)));
extern int obstack_vprintf (struct obstack *__restrict __obstack,
__const char *__restrict __format,
__gnuc_va_list __args)
throw () __attribute__ ((__format__ (__printf__, 2, 0)));
extern void flockfile (FILE *__stream) throw ();
extern int ftrylockfile (FILE *__stream) throw () ;
extern void funlockfile (FILE *__stream) throw ();
# 912 "/opt/s5toolsl21/syslx_eabi/usr/include/stdio.h" 3 4
}
# 24 "bitsBug.cxx" 2
typedef unsigned int uint32_t;
union BugType {
struct fieldType {
uint32_t a : 15;
uint32_t b : 1;
uint32_t : 16;
} field;
uint32_t word;
};
extern bool doRead( const uint32_t count, const uint32_t size, BugType bits1,
BugType bits2 );
int main( int argc, char *argv[] )
{
uint32_t count = 0x10;
uint32_t size = 0x40;
BugType bits1, bits2;
bits1.word = 0x0030;
bits2.word = 0x8030;
if( doRead(count, size, bits1, bits2) ) {
printf( "Passed.\n" );
return 0;
}
printf( "Failed!\n" );
return 42;
}
bool doRead( const uint32_t count, const uint32_t size, BugType bits1, BugType
bits2 )
{
if( (bits1.field.a + count) >= size ) {
bits1.field.b = !bits1.field.b;
bits1.field.a -= size;
}
bits1.field.a += count;
if( bits1.field.b == bits2.field.b ) {
if( bits1.field.a > bits2.field.a ) {
return false;
}
} else {
if( bits1.field.a < bits2.field.a ) {
return false;
}
}
return true;
}
--
Summary: Arm EABI C++ optimiser handles bit fields incorrectly
Product: gcc
Version: 4.2.3
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: john dot spelis at 3dlabs dot com
GCC build triplet: i686-pc-linux-gcc
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: arm-*-linux-gnueabi
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36122
