xtensa: Improve shift operations more
This patch introduces funnel shifter utilization, and rearranges existing
"per-byte shift" insn patterns.
gcc/ChangeLog:
* config/xtensa/predicates.md (logical_shift_operator,
xtensa_shift_per_byte_operator): New predicates.
* config/xtensa/xtensa-protos.h (xtensa_shlrd_which_direction):
New prototype.
* config/xtensa/xtensa.cc (xtensa_shlrd_which_direction):
New helper function for funnel shift patterns.
* config/xtensa/xtensa.md (ior_op): New code iterator.
(*ashlsi3_1): Replace with new split pattern.
(*shift_per_byte): Unify *ashlsi3_3x, *ashrsi3_3x and *lshrsi3_3x.
(*shift_per_byte_omit_AND_0, *shift_per_byte_omit_AND_1):
New insn-and-split patterns that redirect to *xtensa_shift_per_byte,
in order to omit unnecessary bitwise AND operation.
(*shlrd_reg_<code>, *shlrd_const_<code>, *shlrd_per_byte_<code>,
*shlrd_per_byte_<code>_omit_AND):
New insn patterns for funnel shifts.
gcc/testsuite/ChangeLog:
* gcc.target/xtensa/funnel_shifter.c: New.