re PR rtl-optimization/83628 (performance regression when accessing arrays on alpha)

re PR rtl-optimization/83628 (performance regression when accessing arrays on alpha)

	PR target/83628
	* config/alpha/alpha.md (ashlsi3): New insn pattern.
	(*ashlsi_se): Rename from *ashldi_se.  Define as sign
	extension of SImode operation.  Use const123_operand predicate.
	(*saddsi_1): Remove.
	(*saddl_se_1): Ditto.
	(*ssubsi_1): Ditto.
	(*ssubl_se_1): Ditto.
	* config/alpha/predicates.md (const123_operand): New predicate.
	* config/alpha/constraints.md (P): Use IN_RANGE.

From-SVN: r260760