Hi all,
I'm pinging this patch
(https://gcc.gnu.org/ml/gcc-patches/2018-02/msg00444.html)
now that Jeff has approved the prerequisite simplify-rtx.c change
(https://gcc.gnu.org/ml/gcc-patches/2018-03/msg00143.html) (thanks!)
Thanks,
Kyrill
On 08/02/18 17:10, Kyrill Tkachov wrote:
Hi all,
This is a followup to the other PR target/84164 patch [1] that fixes the
testsuite regression
gcc.target/aarch64/bfxil_1.c.
The regression is that with the new subreg+masking simplification we no longer
match the
pattern for BFXIL that has the form:
(set (zero_extract:DI (reg/v:DI 76 [ a ])
(const_int 8 [0x8])
(const_int 0 [0]))
(zero_extract:DI (reg/v:DI 76 [ a ])
(const_int 8 [0x8])
(const_int 16 [0x10])))
This is now instead represented as:
(set (zero_extract:DI (reg/v:DI 93 [ a ])
(const_int 8 [0x8])
(const_int 0 [0]))
(lshiftrt:DI (reg/v:DI 93 [ a ])
(const_int 16 [0x10])))
As far as I can see the two are equivalent semantically and the LSHIFTRT form
is a bit
simpler, so I think the simplified form is valid, but we have no pattern to
match it.
This patch adds that pattern to catch this form as well.
This fixes the aforementioned regression and bootstrap and testing on
aarch64-none-linux-gnu
shows no problem.
Is this ok for trunk if the first patch goes in?
Thanks,
Kyrill
[1] https://gcc.gnu.org/ml/gcc-patches/2018-02/msg00443.html
2018-02-08 Kyrylo Tkachov <[email protected]>
PR target/84164
* config/aarch64/aarch64.md (*extr_insv_lower_reg_lshiftrt<mode>):
New pattern.
