PPC e500, snprintf and valist

[claude vittoria]

claude vittoria wrote:
>>
>>    Hi,
>>
>>    I get a problem when I try to display a float or a double with newlib on 8572 board. The value is always 0 (%d and %p is right).
>>
>>    I debug the snprintf and vfprintf. But I get a wall. How and where is the valist done ?
>>    The pointer on double or float seems to be wrong. The fmt is right.
>>
>>
>>    I m looking for where is builtin_vastart and builtin_va_arg and tips to debug.
>>
>>    Thanks,
>>    Claude
>>
>
>The valist is handled by the compiler.
>
>Verify that you have included <stdio.h> in your test program so that the compiler properly knows about the >prototype for the variable argument stdio functions.
>
>
>-- Jeff J.

My include seems good.

Breakpoint 2, snprintf (str=0x3ffffa8 "", size=60, 
    fmt=0x180f830 "hello world %d\n")
    at /home/cvittoria/people/people/cvittoria/script/debug/gcc-4.3.2/newlib/libc/stdio/snprintf.c:110
110	  ret = _vfprintf_r (ptr, &f, fmt, ap);
(gdb) s
_vfprintf_r (data=0x1810088, fp=0x3fffeec, fmt0=0x180f830 "hello world %f\n", 
    ap=0x3fffee0)
    at /home/cvittoria/people/people/cvittoria/script/debug/gcc-4.3.2/newlib/libc/stdio/vfprintf.c:403
403		char *decimal_point = _localeconv_r (data)->decimal_point;

(gdb) p ap
$1 = (struct __va_list_tag *) 0x3fffee0
(gdb) p *ap
$2 = {
  gpr = 3 '\003', 
  fpr = 0 '\0', 
  reserved = 0, 
  overflow_arg_area = 0x3ffff88, 
  reg_save_area = 0x3ffff48
}
(gdb) x/40x 0x3ffff48
0x3ffff48:	0x03ffffa8	0x0000003c	0x00000000	0x01810088
0x3ffff58:	0x00000000	0x0000000e	0x01810000	0x00000000
0x3ffff68:	0x0180f844	0x0000003b	0x0180f841	0x018000a8

0x01810088 is not the right pointer to my double, the pointed value is null.

I don't get the problem with gcc+glibc. I continue to debug. My board is a e500v2 core.

Claude