[PATCH V4 1/4] rs6000: build constant via li;rotldi
Hi, If a constant is possible to be rotated to/from a positive or negative value from "li", then "li;rotldi" can be used to build the constant. Compare with the previous version: https://gcc.gnu.org/pipermail/gcc-patches/2023-June/621961.html This patch just did minor changes to the style and comments. Bootstrap and regtest pass on ppc64{,le}. Since the previous version is approved with conditions, this version explained the concern too. If no objection, I would like to apply this patch to trunk. BR, Jeff (Jiufu) gcc/ChangeLog: * config/rs6000/rs6000.cc (can_be_built_by_li_and_rotldi): New function. (rs6000_emit_set_long_const): Call can_be_built_by_li_and_rotldi. gcc/testsuite/ChangeLog: * gcc.target/powerpc/const-build.c: New test. --- gcc/config/rs6000/rs6000.cc | 47 +-- .../gcc.target/powerpc/const-build.c | 57 +++ 2 files changed, 98 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/gcc.target/powerpc/const-build.c diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc index 42f49e4a56b..acc332acc05 100644 --- a/gcc/config/rs6000/rs6000.cc +++ b/gcc/config/rs6000/rs6000.cc @@ -10258,6 +10258,31 @@ rs6000_emit_set_const (rtx dest, rtx source) return true; } +/* Check if value C can be built by 2 instructions: one is 'li', another is + rotldi. + + If so, *SHIFT is set to the shift operand of rotldi(rldicl), and *MASK + is set to the mask operand of rotldi(rldicl), and return true. + Return false otherwise. */ + +static bool +can_be_built_by_li_and_rotldi (HOST_WIDE_INT c, int *shift, + HOST_WIDE_INT *mask) +{ + /* If C or ~C contains at least 49 successive zeros, then C can be rotated + to/from a positive or negative value that 'li' is able to load. */ + int n; + if (can_be_rotated_to_lowbits (c, 15, &n) + || can_be_rotated_to_lowbits (~c, 15, &n)) +{ + *mask = HOST_WIDE_INT_M1; + *shift = HOST_BITS_PER_WIDE_INT - n; + return true; +} + + return false; +} + /* Subroutine of rs6000_emit_set_const, handling PowerPC64 DImode. Output insns to set DEST equal to the constant C as a series of lis, ori and shl instructions. */ @@ -10266,15 +10291,14 @@ static void rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c) { rtx temp; + int shift; + HOST_WIDE_INT mask; HOST_WIDE_INT ud1, ud2, ud3, ud4; ud1 = c & 0x; - c = c >> 16; - ud2 = c & 0x; - c = c >> 16; - ud3 = c & 0x; - c = c >> 16; - ud4 = c & 0x; + ud2 = (c >> 16) & 0x; + ud3 = (c >> 32) & 0x; + ud4 = (c >> 48) & 0x; if ((ud4 == 0x && ud3 == 0x && ud2 == 0x && (ud1 & 0x8000)) || (ud4 == 0 && ud3 == 0 && ud2 == 0 && ! (ud1 & 0x8000))) @@ -10305,6 +10329,17 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c) emit_move_insn (dest, gen_rtx_XOR (DImode, temp, GEN_INT ((ud2 ^ 0x) << 16))); } + else if (can_be_built_by_li_and_rotldi (c, &shift, &mask)) +{ + temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode); + unsigned HOST_WIDE_INT imm = (c | ~mask); + imm = (imm >> shift) | (imm << (HOST_BITS_PER_WIDE_INT - shift)); + + emit_move_insn (temp, GEN_INT (imm)); + if (shift != 0) + temp = gen_rtx_ROTATE (DImode, temp, GEN_INT (shift)); + emit_move_insn (dest, temp); +} else if (ud3 == 0 && ud4 == 0) { temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode); diff --git a/gcc/testsuite/gcc.target/powerpc/const-build.c b/gcc/testsuite/gcc.target/powerpc/const-build.c new file mode 100644 index 000..69b37e2bb53 --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/const-build.c @@ -0,0 +1,57 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -save-temps" } */ +/* { dg-require-effective-target has_arch_ppc64 } */ + +/* Verify that two instructions are sucessfully used to build constants. + One insn is li or lis, another is rotate: rldicl, rldicr or rldic. */ + +#define NOIPA __attribute__ ((noipa)) + +struct fun +{ + long long (*f) (void); + long long val; +}; + +long long NOIPA +li_rotldi_1 (void) +{ + return 0x75310LL; +} + +long long NOIPA +li_rotldi_2 (void) +{ + return 0x2164LL; +} + +long long NOIPA +li_rotldi_3 (void) +{ + return 0x8531LL; +} + +long long NOIPA +li_rotldi_4 (void) +{ + return 0x2194LL; +} + +struct fun arr[] = { + {li_rotldi_1, 0x75310LL}, + {li_rotldi_2, 0x2164LL}, + {li_rotldi_3, 0x8531LL}, + {li_rotldi_4, 0x2194LL}, +}; + +/* { dg-final { scan-assembler-times {\mrotldi\M} 4 } } */ + +int +main () +{ + for (int i = 0; i < sizeof (arr) / sizeof (arr[0]); i++) +if ((*arr[i].f) () != arr[i].val) + __builtin_abort (); + + return 0; +} -- 2.39.3
Re: [PATCH V4 1/4] rs6000: build constant via li;rotldi
Hi Segher, As discussed on "~" vs. "-", "~" is correct for this patch. I updated the patch according to Kewen's comments. If ok, I would commit to trunk. BR, Jeff (Jiufu Guo) On 2023-07-04 11:28, Kewen.Lin wrote: Hi Jeff, on 2023/7/4 10:18, Jiufu Guo via Gcc-patches wrote: Hi, If a constant is possible to be rotated to/from a positive or negative value from "li", then "li;rotldi" can be used to build the constant. Compare with the previous version: https://gcc.gnu.org/pipermail/gcc-patches/2023-June/621961.html This patch just did minor changes to the style and comments. Bootstrap and regtest pass on ppc64{,le}. Since the previous version is approved with conditions, this version explained the concern too. If no objection, I would like to apply this patch to trunk. BR, Jeff (Jiufu) gcc/ChangeLog: * config/rs6000/rs6000.cc (can_be_built_by_li_and_rotldi): New function. (rs6000_emit_set_long_const): Call can_be_built_by_li_and_rotldi. gcc/testsuite/ChangeLog: * gcc.target/powerpc/const-build.c: New test. --- gcc/config/rs6000/rs6000.cc | 47 +-- .../gcc.target/powerpc/const-build.c | 57 +++ 2 files changed, 98 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/gcc.target/powerpc/const-build.c diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc index 42f49e4a56b..acc332acc05 100644 --- a/gcc/config/rs6000/rs6000.cc +++ b/gcc/config/rs6000/rs6000.cc @@ -10258,6 +10258,31 @@ rs6000_emit_set_const (rtx dest, rtx source) return true; } +/* Check if value C can be built by 2 instructions: one is 'li', another is + rotldi. Nit: different style, li is with "'" but rotldi isn't. + + If so, *SHIFT is set to the shift operand of rotldi(rldicl), and *MASK + is set to the mask operand of rotldi(rldicl), and return true. + Return false otherwise. */ + +static bool +can_be_built_by_li_and_rotldi (HOST_WIDE_INT c, int *shift, + HOST_WIDE_INT *mask) +{ + /* If C or ~C contains at least 49 successive zeros, then C can be rotated + to/from a positive or negative value that 'li' is able to load. */ + int n; + if (can_be_rotated_to_lowbits (c, 15, &n) + || can_be_rotated_to_lowbits (~c, 15, &n)) +{ + *mask = HOST_WIDE_INT_M1; + *shift = HOST_BITS_PER_WIDE_INT - n; + return true; +} + + return false; +} + /* Subroutine of rs6000_emit_set_const, handling PowerPC64 DImode. Output insns to set DEST equal to the constant C as a series of lis, ori and shl instructions. */ @@ -10266,15 +10291,14 @@ static void rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c) { rtx temp; + int shift; + HOST_WIDE_INT mask; HOST_WIDE_INT ud1, ud2, ud3, ud4; ud1 = c & 0x; - c = c >> 16; - ud2 = c & 0x; - c = c >> 16; - ud3 = c & 0x; - c = c >> 16; - ud4 = c & 0x; + ud2 = (c >> 16) & 0x; + ud3 = (c >> 32) & 0x; + ud4 = (c >> 48) & 0x; if ((ud4 == 0x && ud3 == 0x && ud2 == 0x && (ud1 & 0x8000)) || (ud4 == 0 && ud3 == 0 && ud2 == 0 && ! (ud1 & 0x8000))) @@ -10305,6 +10329,17 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c) emit_move_insn (dest, gen_rtx_XOR (DImode, temp, GEN_INT ((ud2 ^ 0x) << 16))); } + else if (can_be_built_by_li_and_rotldi (c, &shift, &mask)) +{ + temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode); + unsigned HOST_WIDE_INT imm = (c | ~mask); + imm = (imm >> shift) | (imm << (HOST_BITS_PER_WIDE_INT - shift)); + + emit_move_insn (temp, GEN_INT (imm)); + if (shift != 0) + temp = gen_rtx_ROTATE (DImode, temp, GEN_INT (shift)); + emit_move_insn (dest, temp); +} else if (ud3 == 0 && ud4 == 0) { temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode); diff --git a/gcc/testsuite/gcc.target/powerpc/const-build.c b/gcc/testsuite/gcc.target/powerpc/const-build.c new file mode 100644 index 000..69b37e2bb53 --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/const-build.c @@ -0,0 +1,57 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -save-temps" } */ +/* { dg-require-effective-target has_arch_ppc64 } */ + +/* Verify that two instructions are sucessfully used to build constants. s/sucessfully/successfully/ + One insn is li or lis, another is rotate: rldicl, rldicr or rldic. */ Nit: This patch is for insn li + insn rldicl only, you probably want to keep consistent in the comments. The others look good to me, thanks! Segher had one question on "~c" before, I saw you had explained for it, it makes sense to me, but in case he has more questions I'd defer the final approval to him. BR, Kewen
Re: [PATCH V4 1/4] rs6000: build constant via li;rotldi
Hi Jeff, on 2023/7/4 10:18, Jiufu Guo via Gcc-patches wrote: > Hi, > > If a constant is possible to be rotated to/from a positive or negative > value from "li", then "li;rotldi" can be used to build the constant. > > Compare with the previous version: > https://gcc.gnu.org/pipermail/gcc-patches/2023-June/621961.html > This patch just did minor changes to the style and comments. > > Bootstrap and regtest pass on ppc64{,le}. > > Since the previous version is approved with conditions, this version > explained the concern too. If no objection, I would like to apply > this patch to trunk. > > > BR, > Jeff (Jiufu) > > gcc/ChangeLog: > > * config/rs6000/rs6000.cc (can_be_built_by_li_and_rotldi): New function. > (rs6000_emit_set_long_const): Call can_be_built_by_li_and_rotldi. > > gcc/testsuite/ChangeLog: > > * gcc.target/powerpc/const-build.c: New test. > --- > gcc/config/rs6000/rs6000.cc | 47 +-- > .../gcc.target/powerpc/const-build.c | 57 +++ > 2 files changed, 98 insertions(+), 6 deletions(-) > create mode 100644 gcc/testsuite/gcc.target/powerpc/const-build.c > > diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc > index 42f49e4a56b..acc332acc05 100644 > --- a/gcc/config/rs6000/rs6000.cc > +++ b/gcc/config/rs6000/rs6000.cc > @@ -10258,6 +10258,31 @@ rs6000_emit_set_const (rtx dest, rtx source) >return true; > } > > +/* Check if value C can be built by 2 instructions: one is 'li', another is > + rotldi. Nit: different style, li is with "'" but rotldi isn't. > + > + If so, *SHIFT is set to the shift operand of rotldi(rldicl), and *MASK > + is set to the mask operand of rotldi(rldicl), and return true. > + Return false otherwise. */ > + > +static bool > +can_be_built_by_li_and_rotldi (HOST_WIDE_INT c, int *shift, > +HOST_WIDE_INT *mask) > +{ > + /* If C or ~C contains at least 49 successive zeros, then C can be rotated > + to/from a positive or negative value that 'li' is able to load. */ > + int n; > + if (can_be_rotated_to_lowbits (c, 15, &n) > + || can_be_rotated_to_lowbits (~c, 15, &n)) > +{ > + *mask = HOST_WIDE_INT_M1; > + *shift = HOST_BITS_PER_WIDE_INT - n; > + return true; > +} > + > + return false; > +} > + > /* Subroutine of rs6000_emit_set_const, handling PowerPC64 DImode. > Output insns to set DEST equal to the constant C as a series of > lis, ori and shl instructions. */ > @@ -10266,15 +10291,14 @@ static void > rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c) > { >rtx temp; > + int shift; > + HOST_WIDE_INT mask; >HOST_WIDE_INT ud1, ud2, ud3, ud4; > >ud1 = c & 0x; > - c = c >> 16; > - ud2 = c & 0x; > - c = c >> 16; > - ud3 = c & 0x; > - c = c >> 16; > - ud4 = c & 0x; > + ud2 = (c >> 16) & 0x; > + ud3 = (c >> 32) & 0x; > + ud4 = (c >> 48) & 0x; > >if ((ud4 == 0x && ud3 == 0x && ud2 == 0x && (ud1 & 0x8000)) >|| (ud4 == 0 && ud3 == 0 && ud2 == 0 && ! (ud1 & 0x8000))) > @@ -10305,6 +10329,17 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT > c) >emit_move_insn (dest, gen_rtx_XOR (DImode, temp, >GEN_INT ((ud2 ^ 0x) << 16))); > } > + else if (can_be_built_by_li_and_rotldi (c, &shift, &mask)) > +{ > + temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode); > + unsigned HOST_WIDE_INT imm = (c | ~mask); > + imm = (imm >> shift) | (imm << (HOST_BITS_PER_WIDE_INT - shift)); > + > + emit_move_insn (temp, GEN_INT (imm)); > + if (shift != 0) > + temp = gen_rtx_ROTATE (DImode, temp, GEN_INT (shift)); > + emit_move_insn (dest, temp); > +} >else if (ud3 == 0 && ud4 == 0) > { >temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode); > diff --git a/gcc/testsuite/gcc.target/powerpc/const-build.c > b/gcc/testsuite/gcc.target/powerpc/const-build.c > new file mode 100644 > index 000..69b37e2bb53 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/powerpc/const-build.c > @@ -0,0 +1,57 @@ > +/* { dg-do run } */ > +/* { dg-options "-O2 -save-temps" } */ > +/* { dg-require-effective-target has_arch_ppc64 } */ > + > +/* Verify that two instructions are sucessfully used to build constants. s/sucessfully/successfully/ > + One insn is li or lis, another is rotate: rldicl, rldicr or rldic. */ Nit: This patch is for insn li + insn rldicl only, you probably want to keep consistent in the comments. The others look good to me, thanks! Segher had one question on "~c" before, I saw you had explained for it, it makes sense to me, but in case he has more questions I'd defer the final approval to him. BR, Kewen