2009-04-02  Chao-ying Fu  <fu@mips.com>
	    James Grosbach <james.grosbach@microchip.com>

	* config/mips/mips.c (mips_frame_info): Add acc_mask, num_acc,
	num_cop0_regs, acc_save_offset, cop0_save_offset, acc_sp_offset,
	cop0_sp_offset.
	(machine_function): Add interrupt_handler_p, use_shadow_register_set_p,
	keep_interrupts_masked_p, use_debug_exception_return_p.
	(mips_attribute_table): Add interrupt, use_shadow_register_set,
	keep_interrupts_masked, use_debug_exception_return.
	(mips_interrupt_type_p, mips_use_shadow_register_set_p,
	mips_keep_interrupts_masked_p, mips_use_debug_exception_return_p):
	New functions.
	(mips_function_ok_for_sibcall): Return false for interrupt handlers.
	(mips_print_operand): Process COP0 registers to print $0 .. $31
	correctly for GAS to process.
	(mips_interrupt_extra_call_saved_reg_p): New function.
	(mips_cfun_call_saved_reg_p): For interrupt handlers, we need to check
	extra registers.
	(mips_cfun_might_clobber_call_saved_reg_p): Likewise.
	(mips_compute_frame_info): Add supports for interrupt context that
	includes doubleword accumulators and COP0 registers.
	(mips_for_each_saved_acc): New function.
	(mips_for_each_saved_gpr_and_fpr): Change the function name from
	mips_for_each_saved_reg.
	(mips_save_reg): Save accumulators.
	(mips_kernel_reg_p): A new for_each_rtx callback.
	(mips_expand_prologue): Support interrupt handlers.
	(mips_restore_reg): Restore accumulators.
	(mips_expand_epilogue): Support interrupt handlers.
	(mips_can_use_return_insn): Return false for interrupt handlers.
	(mips_epilogue_uses): New function.
	* config/mips/mips.md (UNSPEC_ERET, UNSPEC_DERET, UNSPEC_DI,
	UNSPEC_EHB, UNSPEC_RDPGPR, UNSPEC_COP0): New UNSPEC.
	(mips_eret, mips_deret, mips_di, mips_ehb, mips_rdpgpr,
	cop0_move): New instructions.
	* config/mips/mips-protos.h (mips_epilogue_uses): Declare.
	* config/mips/mips.h (K0_REG_NUM, K1_REG_NUM, KERNEL_REG_P): New
	defines.
	(COP0_STATUS_REG_NUM, COP0_CAUSE_REG_NUM, COP0_EPC_REG_NUM):
	New defines.
	(CAUSE_IPL, SR_IPL, SR_EXL, SR_IE): New defines.
	(MIPS_PROLOGUE_TEMP_REGNUM, MIPS_EPILOGUE_TEMP_REGNUM): For
	interrupt handlers, we use K0 as the temporary register.
	(EPILOGUE_USES): Change to a function call.
	* config/mips/sde.h (MIPS_EPILOGUE_TEMP_REGNUM): For interrupt
	handlers, we use K0 as the temporary register.

	* doc/extend.texi (Function Attributes): Document interrupt,
	use_shadow_register_set, keep_interrupts_masked,
	use_debug_exception_return for MIPS attributes.

Co-Authored-By: James Grosbach <james.grosbach@microchip.com>

From-SVN: r145481