(dfhigh, dflow, sfhigh, sflow): New variables.

(dfhigh, dflow, sfhigh, sflow): New variables.
(mips_sw_reg_names): Consistently use $ as name prefix.
(large_int): Handle 64 bit constants.
(reg_or_0_operand, mips_const_double_ok): Don't examine
CONST_DOUBLE internals.
(mips_const_double_ok): Use REAL_VALUE_* macros.
(simple_memory_operand): Add 64 bit support.  Only test
TARGET_GP_OPT to determine if doing gp optimizations.  Pass
address not MEM to eliminate_constant_term.  Use SMALL_INT.
(mips_fill_delay_slot): Add 64 bit support.
(mips_move_1word): Add 64 bit support.  Don't examine CONST_DOUBLE
internals.
(mips_move_2words): Likewise.
(mips_address_cost): Pass address not MEM to
eliminate_constant_term.  Use SMALL_INT.
(gen_int_relational): New variable mode.  Add 64 bit support.
(gen_conditional_branch): Add 64 bit support.
(block_move_load_store, block_move_loop, block_move_call,
expand_block_move, output_block_move, function_arg_advance,
function_arg, function_arg_partial_nregs): Likewise.
(override_options): Clear MASK_GPOPT if threshold is zero or
negative.  Set MASK_GPOPT if optimizing.  Set mips_isa from -misa=
option, else from MIPS_ISA_DEFAULT if defined, else to 1.  Make
default cpu depend on isa.  Add cpus r4400, r4600, orion.  Rewrite
TARGET_NAME_REGS support.  Initialize dfhigh, dflow, sfhigh,
sflow.  Add 64 bit support.
(print_operand): Use REAL_VALUE_* macros.
(mips_output_external): Don't depend on mips_section_threshold.
(make_temp_file): Define P_tmpdir when __MSDOS__.  Malloc filename
string.  Don't unlink temp file when __MSDOS__.
(mips_asm_file_start): Delete TARGET_NAME_REGS support.
(mips_asm_file_end): Unlike temp file when __MSDOS__.
(mips_declare_object): Don't test mips_sections_threshold.
(compute_frame_size, save_restore_insns, function_prologue,
mips_expand_prologue, function_epilogue, mips_expand_epilogue):
Add 64 bit support.
(function_epilogue): Correctly output `#' before .set volatile.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@6391 138bc75d-0d04-0410-961f-82ee72b054a4