re PR target/70799 (STV pass does not convert DImode shifts)

re PR target/70799 (STV pass does not convert DImode shifts)

	PR target/70799
	* config/i386/i386.c (dimode_scalar_to_vector_candidate_p)
	<case ASHIFT, case LSHIFTRT>: Also consider variable shifts.
	Check "XEXP (src, 1)" operand here.
	<case PLUS, case MINUS, case IOR, case XOR, case AND>:
	Check "XEXP (src, 1)" operand here.
	(dimode_scalar_chain::make_vector_copies): Detect count register
	of a shift instruction.  Zero extend count register from QImode
	to DImode to satisfy vector shift pattern count operand predicate.
	Substitute vector shift count operand with a DImode copy.
	(dimode_scalar_chain::convert_reg): Ditto, zero-extend from
	vector register.

testsuite/ChangeLog:

	PR target/70799
	* gcc.target/i186/pr70799-4.c: New test.

From-SVN: r247082