re PR target/51931 (No support for MIPS16 long branches)

re PR target/51931 (No support for MIPS16 long branches)

gcc/
	PR target/51931
	* config/mips/mips-protos.h (mips_strip_unspec_address): Declare.
	* config/mips/mips.c (mips_strip_unspec_address): Make extern.
	(mips16_rewrite_pool_constant): Make a copy of the pool constant
	before adding to a PC-relative table.
	(mips16_lay_out_constants): Add a SPLIT_P parameter.
	(mips16_load_branch_target, mips16_split_long_branches): New functions.
	(mips_reorg): Update call to mips16_lay_out_constants.
	Call mips16_split_long_branches.
	* config/mips/predicates.md (pc_or_label_operand): Delete.
	* config/mips/mips.md (length): Add a calculation for MIPS16 branches.
	Move the extended_mips16 handling further down.
	(*branch_equality<mode>_mips16): Replace use pc_or_label_operand
	with explicit label_ref and pc.  Follow the usual operand numbering.
	(*branch_equality<mode>_mips16_inverted): New pattern.
	(*jump_mips16): Add length attribute.
	(indirect_jump_and_restore_<mode>): New pattern.
	(consttable_int): Call mips_strip_unspec_address on the operand.

gcc/testsuite/
	PR target/51931
	* gcc.c-torture/compile/20001226-1.c: Remove nomips16 attribute.
	* g++.dg/opt/longbranch1.C: Likewise.

From-SVN: r190104