Re: Optimizer questions/issues with EBCDIC i370/s390 modes.

[Dave Pitts <dpitts at cozx dot com>]

Ulrich Weigand wrote:

> Dave Pitts wrote:
>
> > 3. This fails in both native and cross compile modes. The macros in
> > longlong.h for the i370 appear to fail when compiling _udiv_w_sdiv:
> Yes, they are broken.  They try to express a matching constraint
> between a single-register operand and one subreg of a multi-register
> operand, which unfortunately reload doesn't support (would be nice
> if it did ...).
>
> I've been experimenting with this patch
> (See attached file: longlong.diff)
> which fixes the broken constraints (at the cost of more inefficient code)
> and activates the longlong.h macros also for s390.  (This version of
> longlong.h corresponds to the one from GMP, b.t.w.)
>
> If this works for you, we could look into integrating this patch.
The error seems to point at the sdiv_qrnnd macro:

./xgcc -B./ -B/usr/local/i370-ibm-openedition/bin/ -isystem 
/usr/local/i370-ibm-openedition/include -isystem 
/usr/local/i370-ibm-openedition/sys-include -S -O2  -DIN_GCC 
-DCROSS_COMPILE   -W -Wall -Wwrite-strings -Wstrict-prototypes 
-Wmissing-prototypes -isystem ./include     -DIN_LIBGCC2 
-D__GCC_FLOAT_NOT_NEEDED -Dinhibit_libc -I. -I. -I../../gcc-3.2/gcc 
-I../../gcc-3.2/gcc/. -I../../gcc-3.2/gcc/config 
-I../../gcc-3.2/gcc/../include  -DL_udiv_w_sdiv -c 
../../gcc-3.2/gcc/libgcc2.c -fexceptions -fnon-call-exceptions -o 
libgcc/./_udiv_w_sdiv.o
../../gcc-3.2/gcc/libgcc2.c: In function `__udiv_w_sdiv':
../../gcc-3.2/gcc/libgcc2.c:403: `asm' operand requires impossible reload
../../gcc-3.2/gcc/libgcc2.c:427: `asm' operand requires impossible reload
make[1]: *** [libgcc/./_udiv_w_sdiv.o] Error 1


Code on lines 403 & 427 are calling the sdiv_qrnnd macro. The multiply 
macros with your
changes compile (haven't tried to execute them).

> Mit freundlichen Gruessen / Best Regards
>
> Ulrich Weigand
>
> --
>  Dr. Ulrich Weigand
>  Linux for S/390 Design & Development
>  IBM Deutschland Entwicklung GmbH, Schoenaicher Str. 220, 71032 Boeblingen
>  Phone: +49-7031/16-3727   ---   Email: Ulrich.Weigand@de.ibm.com

--
Dave Pitts                   PULLMAN: Travel and sleep in safety and comfort.
dpitts@cozx.com              My other RV IS a Pullman (Colorado Pine). 
http://www.cozx.com/~dpitts