gcc

gcc

[David Rundle]

hi i need help i have a data struct that matchs some hardwear but 
gcc is alignin it this meins it is out of sync whit the hardwear 
like 
char is              2 bytes 
long double is 12 bytes 
will thats what gcc thinks 

so i need to tell gcc not to align the data struct 

may be like 

noalign struct ........ 

the main prob is whit long double st[8] 

gcc make long double 12 bytes when it need to be 10 bytes 
  

think you 
  

struct _i386_fpu_st 
{ 
  long long  significand; 
  unsigned char       exponent   ; 
  /* unsigned long       test ; */ 

} ; 

struct _i386_fpu 
{ 
  unsigned short control ; 
  unsigned short rev0    ; 
  unsigned short status  ; 
  unsigned short rev1    ; 
  unsigned short tag     ; 
  unsigned short rev2    ; 
  unsigned long  instructionPointer ; 
  unsigned short instructionSelector ; 
  unsigned short opcode  ; 
  unsigned long  operandPointer ; 
  unsigned short operandSelector ; 
  unsigned short rev3  ; 
  long double    st[8] ; 

  /* struct _i386_fpu_st st[8] ; */ 

  unsigned long rev[400] ; 

  
} ; 

extern struct _i386_fpu * i386_fpuInit(void) ;

Re: gcc

[Kurt Garloff]

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On Wed, Sep 05, 2001 at 09:04:01AM +1200, David Rundle wrote:
> hi i need help i have a data struct that matchs some hardwear but 
> gcc is alignin it this meins it is out of sync whit the hardwear 
> like 
> char is              2 bytes 
> long double is 12 bytes 
> will thats what gcc thinks 
> 
> so i need to tell gcc not to align the data struct 
> 
> may be like 

__attribute__((packed))

Regards,
-- 
Kurt Garloff                   <kurt@garloff.de>         [Eindhoven, NL]
Physics: Plasma simulations  <K.Garloff@Phys.TUE.NL>  [TU Eindhoven, NL]
Linux: SCSI, Security          <garloff@suse.de>    [SuSE Nuernberg, DE]
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