https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109907
--- Comment #15 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
So there is another way of fixing this. take:
Trying 6 -> 12:
6: r49:SI=r50:SI>>0x1f
REG_DEAD r50:SI
12: r24:QI=r49:SI#0&0x1
REG_DEAD r49:SI
Failed to match this instruction:
(set (reg/i:QI 24 r24)
(neg:QI (subreg:QI (ashiftrt:SI (reg:SI 50)
(const_int 31 [0x1f])) 0)))
It is correct but maybe the subreg should combine with the shift and change it
just (lshiftrt:QI (subreg:QI (reg:SI 50)) (const_int 7)) . Once combine does
that, then maybe that could match ...
What is interesting is subreg1 does the splitting for HI mode .
Maybe Roger could look improving that since he was touching it recently for avr
IIRC.
