GCC/g77-3.0-to-be compiles our NWP correctly - for the first time

[Toon Moene <toon at moene dot indiv dot nluug dot nl>]

L.S.,

Now that the problems with compiling libstdc++-v3 on
alphaev6-unknown-linux-gnu have been dealt with, I am pleased to
announce that the compiler (download of 2000061010UTC) managed to build
our Numerical Weather Forecasting system (around 1300 Fortran routines
and a dozen C routines) correctly on this target.

I wouldn't be surprised if the following fix made this finally possible:

"Fixes gcc.c-torture/execute/20000605-1.c, derived from gtk,
on alphaev6.  The problem was that we'd inherit an existing
DImode value from a floating point value into the SImode
subreg here.

(insn 80 70 71 (set (reg:DI 99)
        (sign_extend:DI (subreg:SI (reg:DI 92) 0))) 1 {*lda-3}
    (nil))

Which of course results in the wrong bit patterns being 
converted back to SFmode.


r~


        * reload1.c (choose_reload_regs): Mind CLASS_CANNOT_CHANGE_SIZE
        while looking for a register to inherit from.
"

because the part that went belly up does a lot of float->int->float
conversions to group observations in geographical (i.e.
latitude/longitude) boxes.

GCC-3.0-pre is somewhat faster than GCC-2.95.2, although it seems not to
honor the -funroll-loops flag.  I'll wait investigating that until Jan
Hubicka's ("Wat zijn die Tsjechen stil") loop patches have gone in.

Cheers,

-- 
Toon Moene - mailto:toon@moene.indiv.nluug.nl - phoneto: +31 346 214290
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
GNU Fortran 77: http://gcc.gnu.org/onlinedocs/g77_news.html
GNU Fortran 95: http://g95.sourceforge.net/ (under construction)