Denis Chertykov wrote:

> Let's wait for
> http://gcc.gnu.org/ml/gcc-patches/2011-10/msg01874.html

As that patch is now upstream, here the updated version.

Difference to the prior implementation of AS1 is:

o If no LPMX instruction is available and more than 2 bytes
  have to be loaded, a libgcc call is used.  This also makes
  the implementation simpler.


o Some functions are more general than actually needed.
  This will reduce the number of changes for the 24-bit
  address spaces.

o There are 2 new predicates to filter out loads from
  non-generic address space. This is needed in shift
  insns for example because they allow mem.

Tested without regressions.

Ok for trunk?

Johann

gcc/
	PR target/49868
	* config/avr/avr.h (ADDR_SPACE_PGM): New address spaces.
	(REGISTER_TARGET_PRAGMAS): New define.
	* config/avr/avr-protos.h (avr_mem_pgm_p): New.
	(avr_load_libgcc_p): New.
	(asm_output_external_libcall): Remove.
	(avr_register_target_pragmas): New.
	(avr_log_t): Add field "progmem".  Order alphabetically.
	* config/avr/avr-log.c (avr_log_set_avr_log): Set avr_log.progmem.
	* config/avr/avr-c.c (langhooks.h): New include.
	(avr_register_target_pragmas): New function. Register address
	space __pgm.
	(avr_cpu_cpp_builtins): Add built-in define __PGM.
	* config/avr/avr-devices.c (avr_arch_types): Set field n_segments.
	
	* config/avr/avr.c: Include "c-family/c-common.h".
	(TARGET_LEGITIMATE_ADDRESS_P): Remove define.
	(TARGET_LEGITIMIZE_ADDRESS): Remove define.
	(TARGET_ADDR_SPACE_SUBSET_P): Define to...
	(avr_addr_space_subset_p): ...this new static function.
	(TARGET_ADDR_SPACE_CONVERT): Define to...
	(avr_addr_space_convert): ...this new static function.
	(TARGET_ADDR_SPACE_ADDRESS_MODE): Define to...
	(avr_addr_space_address_mode): ...this new static function.
	(TARGET_ADDR_SPACE_POINTER_MODE): Define to...
	(avr_addr_space_pointer_mode): ...this new static function.
	(TARGET_ADDR_SPACE_LEGITIMATE_ADDRESS_P): Define to...
	(avr_addr_space_legitimate_address_p): ...this new static function.
	(TARGET_ADDR_SPACE_LEGITIMIZE_ADDRESS): Define to...
	(avr_addr_space_legitimize_address): ...this new static function.
	(avr_mode_code_base_reg_class): Handle address spaces.
	(avr_regno_mode_code_ok_for_base_p): Ditto.
	(lpm_addr_reg_rtx, lpm_reg_rtx, all_regs_rtx): New static variables.
	(avr_option_override): Initialize them.
	(output_reload_in_const): Use all_regs_rtx. Fix signedness of loop
	variables.
	(avr_pgm_segment): New static function.
	(avr_decl_pgm_p, avr_mem_pgm_p): New static functions.
	(avr_out_lpm, avr_out_lpm_no_lpmx): New static functions.
	(output_movqi, output_movhi, output_movsisf, avr_out_movpsi): Call
	avr_out_lpm to handle loads from progmem.
	(avr_load_libgcc_p): New static function.
	(avr_progmem_p): Test if decl is in flash.
	(avr_pgm_pointer_const_p): New static function.
	(avr_nonconst_pointer_addrspace): New static function.
	(avr_pgm_check_var_decl): New static function.
	(avr_insert_attributes): Use it.  Change error message to report
	cause (progmem or address space) when code wants to write to flash.
	(avr_section_type_flags): Unset section flag SECTION_BSS for
	data in progmem.
	
	* config/avr/predicates.md (nop_general_operand): New predicate.
	(nox_general_operand): New predicate.
	* config/avr/avr.md (LPM_REGNO): New define_constant.
	(load<mode>_libgcc): New expander.
	(*load.<mode>.libgcc): New insn.
	(mov<mode>): Handle loads from non-generic AS.
	(movmemhi): Ditto.  Propagate address space information to newly
	created MEM.
	(movqi_insn, *movhi, *movpsi, *movsi, *movsf): Change predicate #1
	to nox_general_operand.
	(ashrqi3, ashrhi3, ashrsi3): Change predicate #1 to nop_general_operand.
	(ashlqi3, *ashlqi3, ashlhi3, ashlsi3): Ditto.
	(lshrqi3, *lshrqi3, lshrhi3, lshrsi3): Ditto.
	(split-lpmx): New split.
	(*ashlhi3_const, *ashlsi3_const, *ashrhi3_const, *ashrsi3_const,
	*lshrhi3_const, *lshrsi3_const): Indent, unquote C.

libgcc/
	PR target/49868
	* config/avr/t-avr (LIB1ASMFUNCS): Add _load_3,  _load_4.
	* config/avr/lib1funcs.S (__load_3, __load_4, __xload_2): New functions.