https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80080
--- Comment #15 from iii at gcc dot gnu.org --- Author: iii Date: Mon Sep 24 14:21:03 2018 New Revision: 264535 URL: https://gcc.gnu.org/viewcvs?rev=264535&root=gcc&view=rev Log: S/390: Fix conditional returns on z196+ S/390 epilogue ends with (parallel [(return) (use %r14)]) instead of the more usual (return) or (simple_return). This sequence is not recognized by the conditional return logic in try_optimize_cfg (). This was introduced for processors older than z196, where it is sometimes profitable to use call-clobbered register for returning instead of %r14. On newer processors we always return via %r14, for which the fact that it's used is already reflected by EPILOGUE_USES. In this case a simple (return) suffices. This patch changes return_use () to emit simple (return)s when returning via %r14. The resulting sequences are recognized by the conditional return logic in try_optimize_cfg (). gcc/ChangeLog: 2018-09-24 Ilya Leoshkevich <i...@linux.ibm.com> PR target/80080 * config/s390/s390.c (s390_emit_epilogue): Do not use PARALLEL RETURN+USE when returning via %r14. gcc/testsuite/ChangeLog: 2018-09-24 Ilya Leoshkevich <i...@linux.ibm.com> PR target/80080 * gcc.target/s390/risbg-ll-3.c: Expect conditional returns. * gcc.target/s390/zvector/vec-cmp-2.c: Likewise. Modified: trunk/gcc/ChangeLog trunk/gcc/config/s390/s390.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/gcc.target/s390/risbg-ll-3.c trunk/gcc/testsuite/gcc.target/s390/zvector/vec-cmp-2.c
