Re: [avr-gcc-list] dtostrf and the dreaded "relocation truncated to fit: R_AVR_13_PCREL" error

[Dmitry K.]

On Friday 06 April 2007 17:10, rtwas wrote:
>             gcc: avr-gcc (GCC) 4.1.1
>            libc: avr-libc-1.4.4
[...]
> /usr/local/atmel/bin/avr-gcc -g -Os -Wall -mcall-prologues
> -mmcu=atmega128 -save-temps   main.o spim.o spim_tmr0.o diag.o uart.o
> cmd.o cmd_spi.o -o avr_sdiag0.obj
> /usr/local/atmel/lib/gcc/avr/4.1.1/../../../../avr/lib/avr5/libc.a(pow.o):
[...]

Oops!
Just now I have noticed, that all math functions are
simultaneously in both libraries: libc and libm.

Look CVS:
   Revision 1.1.2.7
   Fri May 7 17:38:27 2004 UTC  by troth 
   * AvrCommonLibC.am (nodist_libc_a_SOURCES): Add libm.a sources to
   libc.a so that float point libs are available even if the end user
   forgets to use the -lm to link to the math lib.

It is error! Before this it is needed to exclude *all*
short jmp/calls from fplib group!

I objects to this:
  * Modules are strongly interconnected. The quantity of
  short transitions is very great (in comparison with usual
  programs), and their replacement considerably will worsen
  speed and the size.
  * It excludes an opportunity to take advantage of high
  quality arithmetics which gives the compiler.

However, before to correct this, it is necessary to test
all cases: we have libc functions which use a floating arith.

Dmitry.

P.S. Robert, place '-lm' after all object files to avoid error.
If this will not help, try: '-lm -lc -lm'.