Hi, For constant building e.g. r120=0x66666666, which does not fit 'li or lis', 'pli' is used to build this constant via 'emit_move_insn'.
While for a complicated constant, e.g. 0x6666666666666666ULL, when using 'rs6000_emit_set_long_const' to split the constant recursively, it fails to use 'pli' to build the half part constant: 0x66666666. 'rs6000_emit_set_long_const' could be updated to use 'pli' to build half part of the constant when necessary. For example: 0x6666666666666666ULL, "pli 3,1717986918; rldimi 3,3,32,0" can be used. Compare with previous: https://gcc.gnu.org/pipermail/gcc-patches/2023-November/636567.html This verion is refreshed and added with a new testcase. Bootstrap®test pass on ppc64{,le}. Is this ok for trunk? BR, Jeff (Jiufu Guo) gcc/ChangeLog: * config/rs6000/rs6000.cc (rs6000_emit_set_long_const): Add code to use pli for 34bit constant. gcc/testsuite/ChangeLog: * gcc.target/powerpc/const_split_pli.c: New test. --- gcc/config/rs6000/rs6000.cc | 7 +++++++ gcc/testsuite/gcc.target/powerpc/const_split_pli.c | 9 +++++++++ 2 files changed, 16 insertions(+) create mode 100644 gcc/testsuite/gcc.target/powerpc/const_split_pli.c diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc index dbdc72dce5d..2e074a21a05 100644 --- a/gcc/config/rs6000/rs6000.cc +++ b/gcc/config/rs6000/rs6000.cc @@ -10509,6 +10509,13 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c, int *num_insns) GEN_INT (0xffffffff))); }; + if (TARGET_PREFIXED && SIGNED_INTEGER_34BIT_P (c)) + { + /* li/lis/pli */ + count_or_emit_insn (dest, GEN_INT (c)); + return; + } + if ((ud4 == 0xffff && ud3 == 0xffff && ud2 == 0xffff && (ud1 & 0x8000)) || (ud4 == 0 && ud3 == 0 && ud2 == 0 && !(ud1 & 0x8000))) { diff --git a/gcc/testsuite/gcc.target/powerpc/const_split_pli.c b/gcc/testsuite/gcc.target/powerpc/const_split_pli.c new file mode 100644 index 00000000000..626c93084aa --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/const_split_pli.c @@ -0,0 +1,9 @@ +/* { dg-do compile { target lp64 } } */ +/* { dg-options "-O2" } */ +/* { dg-require-effective-target power10_ok } */ + +unsigned long long msk66() { return 0x6666666666666666ULL; } + +/* { dg-final { scan-assembler-times {\mpli\M} 1 } } */ +/* { dg-final { scan-assembler-not {\mli\M} } } */ +/* { dg-final { scan-assembler-not {\mlis\M} } } */ -- 2.25.1
