S/390: Skip LT(G) peephole when literal pool is involved
authorIlya Leoshkevich <iii@linux.ibm.com>
Tue, 20 Nov 2018 09:32:49 +0000 (09:32 +0000)
committerIlya Leoshkevich <iii@gcc.gnu.org>
Tue, 20 Nov 2018 09:32:49 +0000 (09:32 +0000)
commit34a249bc2e3d60683e0e7fe3c68c85ca287f536f
tree03c869fa8394d034c1e26ec4df9aece147b86565
parentdc3221e1e3d3a39d88d2d35103f6f50e3400d7a8
S/390: Skip LT(G) peephole when literal pool is involved

By the time peephole optimizations run, we've already made up our mind
whether to use base-register or relative addressing for literal pool
entries.  LT(G) supports only base-register addressing, and so it is
too late to convert L(G)RL + compare to LT(G).  This change should not
make the code worse unless building with e.g. -fno-dce, since comparing
literal pool entries to zero should be optimized away during earlier
passes.

gcc/ChangeLog:

2018-11-20  Ilya Leoshkevich  <iii@linux.ibm.com>

PR target/88083
* config/s390/s390.md: Skip LT(G) peephole when literal pool is
involved.
* rtl.h (contains_constant_pool_address_p): New function.
* rtlanal.c (contains_constant_pool_address_p): Likewise.

gcc/testsuite/ChangeLog:

2018-11-20  Ilya Leoshkevich  <iii@linux.ibm.com>

PR target/88083
* gcc.target/s390/pr88083.c: New test.

From-SVN: r266306
gcc/ChangeLog
gcc/config/s390/s390.md
gcc/rtl.h
gcc/rtlanal.c
gcc/testsuite/ChangeLog
gcc/testsuite/gcc.target/s390/pr88083.c [new file with mode: 0644]