[Bug target/94135] PPC: subfic instead of neg used for rotate right

[jens.seifert at de dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94135

--- Comment #2 from Jens Seifert <jens.seifert at de dot ibm.com> ---
POWER8 Processor User’s Manual for the Single-Chip Module:

addi addis add add. subf subf. addic subfic adde addme subfme addze. subfze neg
neg. nego

1 - 2 cycles (GPR)
2 cycles (XER)
5 cycles (CR)

6/cycle, 2/cycle (with XER or CR updates)

CA is part of XER.

1-2 cycles versus 2 cycles.