Re: [hatari-devel] Bug in FPU code

[Andreas Grabher <andreas.grabher@xxxxxxxxxxxx>]

The patch to take into account USE_LONG_DOUBLE 0 is a good idea! I applied it to Previous and it works with USE_LONG_DOUBLE 1.


Am 07.03.2012 um 18:51 schrieb Thomas H.:

>> Datum: Wed, 07 Mar 2012 08:50:20 +0100
>> Von: Laurent Sallafranque <laurent.sallafranque@xxxxxxx>
>> 
>> I've compiled with the patch you suggest.
>> Compile runs with 2 warnings:
>> 
>> [ 21%] Building C object src/cpu/CMakeFiles/UaeCpu.dir/fpp.c.o
>> /home/laurent/Atari/hatari/src/cpu/fpp.c: In function ‘to_pack’:
>> /home/laurent/Atari/hatari/src/cpu/fpp.c:339:2: attention : format
>> ‘%Le’ 
>> expects argument of type ‘long double *’, but argument 3 has type 
>> ‘fptype *’ [-Wformat]
>> /home/laurent/Atari/hatari/src/cpu/fpp.c: In function ‘from_pack’:
>> /home/laurent/Atari/hatari/src/cpu/fpp.c:350:2: attention : format
>> ‘%Le’ 
>> expects argument of type ‘long double’, but argument 3 has type
>> ‘fptype’ 
>> [-Wformat]
> 
> Ah, sorry, my bad, I was working with the "previous" sources when I wrote my mail. Actually that problem only happens when using USE_LONG_DOUBLE=1. This is the case for previous. Since we're using USE_LONG_DOUBLE=0 in Hatari, we are not affected of this format string problem. But to be sure, we should maybe add a patch like this:
> 
> diff -r 22d3c9f30097 src/cpu/fpp.c
> --- a/src/cpu/fpp.c	Wed Mar 07 10:08:50 2012 +0100
> +++ b/src/cpu/fpp.c	Wed Mar 07 18:50:43 2012 +0100
> @@ -336,7 +336,11 @@
> 	*cp++ = ((wrd1 >> 20) & 0xf) + '0';
> 	*cp++ = ((wrd1 >> 16) & 0xf) + '0';
> 	*cp = 0;
> +#if USE_LONG_DOUBLE
> +	sscanf (str, "%Le", &d);
> +#else
> 	sscanf (str, "%le", &d);
> +#endif
> 	return d;
> }
> 
> @@ -347,7 +351,11 @@
> 	char *cp;
> 	char str[100];
> 
> +#if USE_LONG_DOUBLE
> +	sprintf (str, "%.16Le", src);
> +#else
> 	sprintf (str, "%.16e", src);
> +#endif
> 	cp = str;
> 	*wrd1 = *wrd2 = *wrd3 = 0;
> 	if (*cp == '-') {
> 
> What do you think?
> 
> Thomas
> 
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