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  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 )) (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 )) (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  https://gcc.gnu.org/ml/gcc-patches/2018-02/msg00443.html 2018-02-08 Kyrylo Tkachov <kyrylo.tkac...@arm.com> PR target/84164 * config/aarch64/aarch64.md (*extr_insv_lower_reg_lshiftrt<mode>): New pattern.