GCC-4.0 vs GCC-3.3.6 ia32 -Os: code size increase from 261 to 5339 bytes

[Giovanni Bajo]

Etienne Lorrain <etienne_lorrain@yahoo.fr> wrote:

> etienne@cygne:~/projet/gujin$ gcc -Os tst.c -c -o tst.o && size tst.o
>    text    data     bss     dec     hex filename
>     261       0       0     261     105 tst.o
> etienne@cygne:~/projet/gujin$ ../toolchain/bin/gcc -Os tst.c -c -o tst.o
&&
> size tst.o
>    text    data     bss     dec     hex filename
>    5339       0       0    5339    14db tst.o
> etienne@cygne:~/projet/gujin$

It's another issue with SRA and -Os. With an old 4.1, I have:

$ ./xgcc -c -Os -B. btst.c && size btst.o
   text    data     bss     dec     hex filename
   5339       0       0    5339    14db btst.o
$ ./xgcc -c -Os -fno-tree-sra -B. btst.c && size btst.o
   text    data     bss     dec     hex filename
    224       0       0     224      e0 btst.o

So we're actually better than 3.3, after we disable -ftree-sra. I guess SRA
should be tuned (disabled?) for -Os.

Please, do file a bugreport.
-- 
Giovanni Bajo