re PR target/51244 ([SH] Inefficient conditional branch and code around T bit)

re PR target/51244 ([SH] Inefficient conditional branch and code around T bit)

	PR target/51244
	* config/sh/sh-protos.h (set_of_reg): New struct.
	(sh_find_set_of_reg, sh_is_logical_t_store_expr,
	sh_try_omit_signzero_extend):  Declare...
	* config/sh/sh.c (sh_find_set_of_reg, sh_is_logical_t_store_expr,
	sh_try_omit_signzero_extend): ...these new functions.
	* config/sh/sh.md (*logical_op_t): New insn_and_split.
	(*zero_extend<mode>si2_compact): Use sh_try_omit_signzero_extend
	in splitter.
	(*extend<mode>si2_compact_reg): Convert to insn_and_split.
	Use sh_try_omit_signzero_extend in splitter.
	(*mov<mode>_reg_reg): Disallow t_reg_operand as operand 1.
	(*cbranch_t): Rewrite combine part in splitter using new
	sh_find_set_of_reg function.

	PR target/51244
	* gcc.target/sh/pr51244-17.c: New.

From-SVN: r192481