Subnormal float support in armv7(with -msoft-float) for intrinsics

[Szabolcs Nagy]

On 12/07/18 16:20, Umesh Kalappa wrote:
> Hi everyone,
> 
> we have our source base ,that was compiled for armv7 on gcc8.1 with
> soft-float and for following input
> 
> a=0x0010000000000000
> b=0x0000000000000001
> 
>   result = a - b ;
> 
> we are getting the result as "0x000ffffffffffffe" and with
> -mhard-float (disabled the flush to zero mode ) we are getting the
> result as ""0x000fffffffffffff" as expected.
> 

please submit it as a bug report to bugzilla

> while debugging the soft-float code,we see that ,the compiler calls
> the intrinsic "__aeabi_dsub" with arm calling conventions i.e passing
> "a" in r0 and r1 registers and respectively for "b".
> 
> we are investigating the routine "__aeabi_dsub" that comes from libgcc
> for incorrect result  and meanwhile we would like to know that
> 
> a)do libgcc routines/intrinsic for float operations support or
> consider the subnormal values ? ,if so how we can enable the same.
> 
> Thank you
> ~Umesh
>