re PR rtl-optimization/12630 (Various unrecognizable insns and ICEs at -O3)

re PR rtl-optimization/12630 (Various unrecognizable insns and ICEs at -O3)

	PR optimization/12630
	* pa.c (compute_movstrsi_length): Rename to compute_movstr_length.
	Handle length computation 64-bit moves.
	(compute_clrstr_length, output_block_clear): Implement block clear.
	(output_block_move): Handle 64-bit moves.
	(pa_adjust_insn_length): Use compute_movstr_length and
	compute_clrstr_length.
	* pa.md (movstrsi): Revise operand order and comments.  Don't use
	match_scratch.
	(movstrsi_internal): Delete.
	(movstrsi_prereload, movstrsi_postreload): New insns.  Define splitter
	and peephole2 patterns to transform prereload to postreload form.
	(movstrdi, movstrdi_prereload, movstrdi_postreload, clrstrsi,
	clrstrsi_prereload, clrstrsi_postreload, clrstrdi, clrstrdi_prereload,
	clrstrdi_postreload): New patterns for 64-bit block move, and block
	clear.
	* pa-protos.h (output_block_clear): New prototype.

From-SVN: r73375