public inbox for gcc@gcc.gnu.org
 help / color / mirror / Atom feed
* Subnormal float support in armv7(with -msoft-float) for intrinsics
@ 2018-07-12 15:20 Umesh Kalappa
  2018-07-12 16:03 ` Szabolcs Nagy
  0 siblings, 1 reply; 6+ messages in thread
From: Umesh Kalappa @ 2018-07-12 15:20 UTC (permalink / raw)
  To: gcc

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.

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

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2018-07-17 10:31 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-07-12 15:20 Subnormal float support in armv7(with -msoft-float) for intrinsics Umesh Kalappa
2018-07-12 16:03 ` Szabolcs Nagy
2018-07-13  7:53   ` Umesh Kalappa
2018-07-17  9:42     ` Umesh Kalappa
2018-07-17  9:54       ` Ramana Radhakrishnan
2018-07-17 10:31         ` Umesh Kalappa

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).