Re: [PATCH] sparc: Fix llrint and llround missing exceptions on SPARC32

[Daniel Cederman <cederman@gaisler.com>]

On 2024-01-12 19:05, Adhemerval Zanella Netto wrote:
> 
> 
> On 12/01/24 06:26, Daniel Cederman wrote:
>> +/* Define these macros to 1 to workaround conversions of out-of-range
>> +   floating-point numbers to integer types failing to raise the
>> +   "invalid" exception, or raising spurious "inexact" or other
>> +   exceptions.  */
> 
> This is not really true for all sparc32, at least with sparcv9 I have
> access I have not seen any issues with missing exception overflows or
> spurious inexact.  Are these some leon3 limitation or issue?
> 

I don't think it is a leon specific issue. I can trigger the same issue 
with QEMU for other sparcs. Sparcv9 has custom versions of the functions 
involved so that is probably why it is not affected:

./sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_llrint.c
./sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_llrintf.c

Corresponding patches for other 32-bit architectures references this 
bugzilla entry:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59412

I will have to look into this again, but I remember that it was a 
similar issue for sparc32.

> I think we need to know exactly how/when this happens and only enable
> such workaound when required.
> 
>> +#define FIX_FLT_LONG_CONVERT_OVERFLOW 0
>> +#define FIX_FLT_LLONG_CONVERT_OVERFLOW 1
>> +#define FIX_DBL_LONG_CONVERT_OVERFLOW 0
>> +#define FIX_DBL_LLONG_CONVERT_OVERFLOW 1
>> +#define FIX_LDBL_LONG_CONVERT_OVERFLOW 0
>> +#define FIX_LDBL_LLONG_CONVERT_OVERFLOW 0
>> +#define FIX_FLT128_LONG_CONVERT_OVERFLOW 0
>> +#define FIX_FLT128_LLONG_CONVERT_OVERFLOW 0
>> +
>> +#endif /* fix-fp-int-convert-overflow.h */