S/390: Merge compare of compare results

S/390: Merge compare of compare results

With this patch EQ and NE compares on CC mode reader patterns are
folded.  This allows using the result of the vec_all_* and vec_any_*
builtins directly in a conditional jump instruction as in the attached
testcase.

gcc/ChangeLog:

2016-12-02  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* config/s390/s390-protos.h (s390_reverse_condition): New
	prototype.
	* config/s390/s390.c (s390_canonicalize_comparison): Fold compares
	of CC mode values.
	(s390_reverse_condition): New function.
	* config/s390/s390.h (REVERSE_CC_MODE, REVERSE_CONDITION): Define
	target macros.

gcc/testsuite/ChangeLog:

2016-12-02  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* gcc.target/s390/zvector/vec-cmp-2.c: New test.

From-SVN: r243155