Hi, I would like to ping this patch: https://gcc.gnu.org/pipermail/gcc-patches/2023-January/609373.html
BR, Jeff (Jiufu) Jiufu Guo <guoji...@linux.ibm.com> writes: > Hi, > > Compare with previous version, this patch updates the comments only. > https://gcc.gnu.org/pipermail/gcc-patches/2022-December/608293.html > > For a complicate 64bit constant, below is one instruction-sequence to > build: > lis 9,0x800a > ori 9,9,0xabcd > sldi 9,9,32 > oris 9,9,0xc167 > ori 9,9,0xfa16 > > while we can also use below sequence to build: > lis 9,0xc167 > lis 10,0x800a > ori 9,9,0xfa16 > ori 10,10,0xabcd > rldimi 9,10,32,0 > This sequence is using 2 registers to build high and low part firstly, > and then merge them. > > In parallel aspect, this sequence would be faster. (Ofcause, using 1 more > register with potential register pressure). > > The instruction sequence with two registers for parallel version can be > generated only if can_create_pseudo_p. Otherwise, the one register > sequence is generated. > > Bootstrap and regtest pass on ppc64{,le}. > Is this ok for trunk? > > > BR, > Jeff(Jiufu) > > > gcc/ChangeLog: > > * config/rs6000/rs6000.cc (rs6000_emit_set_long_const): Generate > more parallel code if can_create_pseudo_p. > > gcc/testsuite/ChangeLog: > > * gcc.target/powerpc/parall_5insn_const.c: New test. > > --- > gcc/config/rs6000/rs6000.cc | 39 +++++++++++++------ > .../gcc.target/powerpc/parall_5insn_const.c | 27 +++++++++++++ > 2 files changed, 54 insertions(+), 12 deletions(-) > create mode 100644 gcc/testsuite/gcc.target/powerpc/parall_5insn_const.c > > diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc > index 6ac3adcec6b..b4f03499252 100644 > --- a/gcc/config/rs6000/rs6000.cc > +++ b/gcc/config/rs6000/rs6000.cc > @@ -10366,19 +10366,34 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT > c) > } > else > { > - temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode); > - > - emit_move_insn (temp, GEN_INT (sext_hwi (ud4 << 16, 32))); > - if (ud3 != 0) > - emit_move_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud3))); > + if (can_create_pseudo_p ()) > + { > + /* lis HIGH,UD4 ; ori HIGH,UD3 ; > + lis LOW,UD2 ; ori LOW,UD1 ; rldimi LOW,HIGH,32,0. */ > + rtx high = gen_reg_rtx (DImode); > + rtx low = gen_reg_rtx (DImode); > + HOST_WIDE_INT num = (ud2 << 16) | ud1; > + rs6000_emit_set_long_const (low, sext_hwi (num, 32)); > + num = (ud4 << 16) | ud3; > + rs6000_emit_set_long_const (high, sext_hwi (num, 32)); > + emit_insn (gen_rotldi3_insert_3 (dest, high, GEN_INT (32), low, > + GEN_INT (0xffffffff))); > + } > + else > + { > + /* lis DEST,UD4 ; ori DEST,UD3 ; rotl DEST,32 ; > + oris DEST,UD2 ; ori DEST,UD1. */ > + emit_move_insn (dest, GEN_INT (sext_hwi (ud4 << 16, 32))); > + if (ud3 != 0) > + emit_move_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud3))); > > - emit_move_insn (ud2 != 0 || ud1 != 0 ? temp : dest, > - gen_rtx_ASHIFT (DImode, temp, GEN_INT (32))); > - if (ud2 != 0) > - emit_move_insn (ud1 != 0 ? temp : dest, > - gen_rtx_IOR (DImode, temp, GEN_INT (ud2 << 16))); > - if (ud1 != 0) > - emit_move_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1))); > + emit_move_insn (dest, gen_rtx_ASHIFT (DImode, dest, GEN_INT (32))); > + if (ud2 != 0) > + emit_move_insn (dest, > + gen_rtx_IOR (DImode, dest, GEN_INT (ud2 << 16))); > + if (ud1 != 0) > + emit_move_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud1))); > + } > } > } > > diff --git a/gcc/testsuite/gcc.target/powerpc/parall_5insn_const.c > b/gcc/testsuite/gcc.target/powerpc/parall_5insn_const.c > new file mode 100644 > index 00000000000..e3a9a7264cf > --- /dev/null > +++ b/gcc/testsuite/gcc.target/powerpc/parall_5insn_const.c > @@ -0,0 +1,27 @@ > +/* { dg-do run } */ > +/* { dg-options "-O2 -mno-prefixed -save-temps" } */ > +/* { dg-require-effective-target has_arch_ppc64 } */ > + > +/* { dg-final { scan-assembler-times {\mlis\M} 4 } } */ > +/* { dg-final { scan-assembler-times {\mori\M} 4 } } */ > +/* { dg-final { scan-assembler-times {\mrldimi\M} 2 } } */ > + > +void __attribute__ ((noinline)) foo (unsigned long long *a) > +{ > + /* 2 lis + 2 ori + 1 rldimi for each constant. */ > + *a++ = 0x800aabcdc167fa16ULL; > + *a++ = 0x7543a876867f616ULL; > +} > + > +long long A[] = {0x800aabcdc167fa16ULL, 0x7543a876867f616ULL}; > +int > +main () > +{ > + long long res[2]; > + > + foo (res); > + if (__builtin_memcmp (res, A, sizeof (res)) != 0) > + __builtin_abort (); > + > + return 0; > +}
