--- Comment #3 from dominiq at lps dot ens dot fr 2008-01-08 10:17 ---
I just had a look to the doc patch in
http://gcc.gnu.org/ml/gcc-patches/2008-01/msg00273.html:
...
+Note that while the throughput of the sequence is higher than the throughput
+of the non-reciprocal instruction, the
--- Comment #2 from dominiq at lps dot ens dot fr 2008-01-08 09:46 ---
I don't think either that this is a regression, only a bad side effect. A
possibility to overcome it would be to change the way theNewton-Raphson
iteration is computed. Presently it seems to be x1=x0*(2.0-x*x0) which
--- Comment #1 from ubizjak at gmail dot com 2008-01-08 08:42 ---
Hm, I don't see the reason, why this is a regression. What this PR shows is the
limitation of the precision of rcpss instruction.
Actually, this 2ulp precision is the reason, why -mrecip is not enabled by
default for -ffa
--
pinskia at gcc dot gnu dot org changed:
What|Removed |Added
GCC build triplet|i686-apple-darwin9 |
GCC host triplet|i686-apple-darwin9 |
GCC target triplet
