S/390: Add add/sub/mul overflow check patterns

S/390: Add add/sub/mul overflow check patterns

This patch implements the addv, subv, and mulv patterns for signed
integers.

gcc/ChangeLog:

2019-07-24  Andreas Krebbel  <krebbel@linux.ibm.com>

	* config/s390/predicates.md (addv_const_operand): New predicate.
	* config/s390/s390-modes.def (CCO): New condition code mode.
	* config/s390/s390.c (s390_match_ccmode_set): Handle E_CCOmode.
	(s390_branch_condition_mask): Likewise.
	* config/s390/s390.md ("addv<mode>4", "subv<mode>4")
	("mulv<mode>4"): New expanders.
	("*addv<mode>3_ccoverflow", "*addv<mode>3_ccoverflow_const")
	("*subv<mode>3_ccoverflow", "*mulv<mode>3_ccoverflow"): New
	pattern definitions.

gcc/testsuite/ChangeLog:

2019-07-24  Andreas Krebbel  <krebbel@linux.ibm.com>

	* gcc.target/s390/addsub-signed-overflow-1.c: New test.
	* gcc.target/s390/addsub-signed-overflow-2.c: New test.
	* gcc.target/s390/mul-signed-overflow-1.c: New test.
	* gcc.target/s390/mul-signed-overflow-2.c: New test.

From-SVN: r273759