Define s390_shift_truncation_mask to allow the optabs optimization sh = (64 - sh) -> sh = -sh
for a rotation operation. -- gcc/ChangeLog: 2019-07-05 Robin Dapp <rd...@linux.ibm.com> * config/s390/s390.c (s390_shift_truncation_mask): Define. (TARGET_SHIFT_TRUNCATION_MASK): Define. gcc/testsuite/ChangeLog: 2019-07-05 Robin Dapp <rd...@linux.ibm.com> * gcc.target/s390/rotate-truncation-mask.c: New test. --- gcc/config/s390/s390.c | 8 ++++++++ .../gcc.target/s390/rotate-truncation-mask.c | 11 +++++++++++ 2 files changed, 19 insertions(+) create mode 100644 gcc/testsuite/gcc.target/s390/rotate-truncation-mask.c diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c index 324d9d23210..75b0b5b4790 100644 --- a/gcc/config/s390/s390.c +++ b/gcc/config/s390/s390.c @@ -16412,7 +16412,13 @@ s390_sched_dependencies_evaluation (rtx_insn *head, rtx_insn *tail) add_dependence (r11_restore, r15_restore, REG_DEP_ANTI); } +/* Implement TARGET_SHIFT_TRUNCATION_MASK for integer shifts. */ +static unsigned HOST_WIDE_INT +s390_shift_truncation_mask (machine_mode mode) +{ + return mode == DImode || mode == SImode ? 63 : 0; +} /* Initialize GCC target structure. */ @@ -16709,6 +16715,8 @@ s390_sched_dependencies_evaluation (rtx_insn *head, rtx_insn *tail) #define TARGET_SCHED_DEPENDENCIES_EVALUATION_HOOK \ s390_sched_dependencies_evaluation +#undef TARGET_SHIFT_TRUNCATION_MASK +#define TARGET_SHIFT_TRUNCATION_MASK s390_shift_truncation_mask /* Use only short displacement, since long displacement is not available for the floating point instructions. */ diff --git a/gcc/testsuite/gcc.target/s390/rotate-truncation-mask.c b/gcc/testsuite/gcc.target/s390/rotate-truncation-mask.c new file mode 100644 index 00000000000..1cdd20913b9 --- /dev/null +++ b/gcc/testsuite/gcc.target/s390/rotate-truncation-mask.c @@ -0,0 +1,11 @@ +/* Check that we do not use (64 - sh) for rotating. */ + +/* { dg-options "-O1 -m64" } */ + +/* { dg-final { scan-assembler "lcr\t%r.+,%r.+" } } */ +/* { dg-final { scan-assembler-not "lhi\t%r.+,64" } } */ +/* { dg-final { scan-assembler-not "sr\t%r.+,%r.+" } } */ +unsigned long rotr (unsigned long in, unsigned long sh) +{ + return (in >> sh) | (in << (64 - sh)); +} -- 2.17.0