This patch adds new utility functions for manipulating REG_ARGS_SIZE
notes and allows the notes to carry polynomial as well as constant sizes.

The code was inconsistent about whether INT_MIN or HOST_WIDE_INT_MIN
should be used to represent an unknown size.  The patch uses
HOST_WIDE_INT_MIN throughout.

2017-12-21  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* rtl.h (get_args_size, add_args_size_note): New functions.
	(find_args_size_adjust): Return a poly_int64 rather than a
	HOST_WIDE_INT.
	(fixup_args_size_notes): Likewise.  Make the same change to the
	end_args_size parameter.
	* rtlanal.c (get_args_size, add_args_size_note): New functions.
	* builtins.c (expand_builtin_trap): Use add_args_size_note.
	* calls.c (emit_call_1): Likewise.
	* explow.c (adjust_stack_1): Likewise.
	* cfgcleanup.c (old_insns_match_p): Update use of
	find_args_size_adjust.
	* combine.c (distribute_notes): Track polynomial arg sizes.
	* dwarf2cfi.c (dw_trace_info): Change beg_true_args_size,
	end_true_args_size, beg_delay_args_size and end_delay_args_size
	from HOST_WIDE_INT to poly_int64.
	(add_cfi_args_size): Take the args_size as a poly_int64 rather
	than a HOST_WIDE_INT.
	(notice_args_size, notice_eh_throw, maybe_record_trace_start)
	(maybe_record_trace_start_abnormal, scan_trace, connect_traces): Track
	polynomial arg sizes.
	* emit-rtl.c (try_split): Use get_args_size.
	* recog.c (peep2_attempt): Likewise.
	* reload1.c (reload_as_needed): Likewise.
	* expr.c (find_args_size_adjust): Return the adjustment as a
	poly_int64 rather than a HOST_WIDE_INT.
	(fixup_args_size_notes): Change end_args_size from a HOST_WIDE_INT
	to a poly_int64 and change the return type in the same way.
	(emit_single_push_insn): Track polynomial arg sizes.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r255919