* config/mips/mips-protos.h (mips_reg_mode_ok_for_base_p): Delete.
	(mips_regno_mode_ok_for_base_p): Declare.
	* config/mips/mips.h (ARG_POINTER_REGNUM): Renumber to 77.
	(FRAME_POINTER_REGNUM): Renumber to 78.
	(FIRST_PSEUDO_REGISTER): Update comment accordingly.
	(BASE_REG_P, GP_REG_OR_PSEUDO_STRICT_P): Delete.
	(GP_REG_OR_PSEUDO_NONSTRICT_P): Delete.
	(REGNO_MODE_OK_FOR_BASE_P): Use mips_regno_mode_ok_for_base_p.
	(REG_MODE_OK_FOR_BASE_P): Likewise.
	* config/mips/mips.c (mips_reg_names, mips_sw_reg_names): Change
	entry for 77 to "$arg" and entry for 78 to "$frame".
	(mips_regno_to_class): Map 77 and 78 to ALL_REGS.
	(mips_reg_mode_ok_for_base_p): Remove.
	(mips_regno_mode_ok_for_base_p): New function, derived from old
	BASE_REG_P macro.  Don't enforce the mips16 stack pointer
	restrictions unless we're being strict.
	(mips_valid_base_register_p): Use mips_regno_mode_ok_for_base_p.

testsuite/
	* gcc.dg/torture/mips-clobber-at.c: New test.

From-SVN: r76547