| Message ID | 20230608015547.3432691-3-guojiufu@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | rs6000: build constant via li/lis;rldicX | expand |
On Wed, Jun 7, 2023 at 9:55 PM Jiufu Guo <guojiufu@linux.ibm.com> wrote: > Hi, > > This patch checks if a constant is possible to be rotated to/from a > negative > value from "lis". If so, we could use "lis;rotldi" to build it. > The positive value of "lis" does not need to be analyzed. Because if a > constant can be rotated from the positive value of "lis", it also can be > rotated from a positive value of "li". > > Bootstrap and regtest pass on ppc64{,le}. > Is this ok for trunk? > > BR, > Jeff (Jiufu) > > gcc/ChangeLog: > > * config/rs6000/rs6000.cc (can_be_rotated_to_negative_lis): New > function. > (can_be_built_by_li_and_rotldi): Rename to ... > (can_be_built_by_li_lis_and_rotldi): ... this function. > (rs6000_emit_set_long_const): Call > can_be_built_by_li_lis_and_rotldi. > This patch is okay. Thanks, David > > gcc/testsuite/ChangeLog: > > * gcc.target/powerpc/const-build.c: Add more tests. > --- > gcc/config/rs6000/rs6000.cc | 42 ++++++++++++++++--- > .../gcc.target/powerpc/const-build.c | 16 ++++++- > 2 files changed, 52 insertions(+), 6 deletions(-) > > diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc > index 1dd0072350a..03cd9d5e952 100644 > --- a/gcc/config/rs6000/rs6000.cc > +++ b/gcc/config/rs6000/rs6000.cc > @@ -10278,19 +10278,51 @@ can_be_rotated_to_negative_li (HOST_WIDE_INT c, > int *rot) > return can_be_rotated_to_lowbits (~c, 15, rot); > } > > -/* Check if value C can be built by 2 instructions: one is 'li', another > is > - rotldi. > +/* Check if C can be rotated to a negative value which 'lis' instruction > is > + able to load: 1..1xx0..0. If so, set *ROT to the number by which C is > + rotated, and return true. Return false otherwise. */ > + > +static bool > +can_be_rotated_to_negative_lis (HOST_WIDE_INT c, int *rot) > +{ > + /* case a. 1..1xxx0..01..1: up to 15 x's, at least 16 0's. */ > + int leading_ones = clz_hwi (~c); > + int tailing_ones = ctz_hwi (~c); > + int middle_zeros = ctz_hwi (c >> tailing_ones); > + if (middle_zeros >= 16 && leading_ones + tailing_ones >= 33) > + { > + *rot = HOST_BITS_PER_WIDE_INT - tailing_ones; > + return true; > + } > + > + /* case b. xx0..01..1xx: some of 15 x's (and some of 16 0's) are > + rotated over the highest bit. */ > + int pos_one = clz_hwi ((c << 16) >> 16); > + middle_zeros = ctz_hwi (c >> (HOST_BITS_PER_WIDE_INT - pos_one)); > + int middle_ones = clz_hwi (~(c << pos_one)); > + if (middle_zeros >= 16 && middle_ones >= 33) > + { > + *rot = pos_one; > + return true; > + } > + > + return false; > +} > + > +/* Check if value C can be built by 2 instructions: one is 'li or lis', > + another is rotldi. > > If so, *SHIFT is set to the shift operand of rotldi(rldicl), and *MASK > is set to -1, and return true. Return false otherwise. */ > > static bool > -can_be_built_by_li_and_rotldi (HOST_WIDE_INT c, int *shift, > +can_be_built_by_li_lis_and_rotldi (HOST_WIDE_INT c, int *shift, > HOST_WIDE_INT *mask) > { > int n; > if (can_be_rotated_to_positive_li (c, &n) > - || can_be_rotated_to_negative_li (c, &n)) > + || can_be_rotated_to_negative_li (c, &n) > + || can_be_rotated_to_negative_lis (c, &n)) > { > *mask = HOST_WIDE_INT_M1; > *shift = HOST_BITS_PER_WIDE_INT - n; > @@ -10346,7 +10378,7 @@ rs6000_emit_set_long_const (rtx dest, > HOST_WIDE_INT c) > emit_move_insn (dest, gen_rtx_XOR (DImode, temp, > GEN_INT ((ud2 ^ 0xffff) << 16))); > } > - else if (can_be_built_by_li_and_rotldi (c, &shift, &mask)) > + else if (can_be_built_by_li_lis_and_rotldi (c, &shift, &mask)) > { > temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode); > unsigned HOST_WIDE_INT imm = (c | ~mask); > diff --git a/gcc/testsuite/gcc.target/powerpc/const-build.c > b/gcc/testsuite/gcc.target/powerpc/const-build.c > index 70f095f6bf2..c38a1dd91f2 100644 > --- a/gcc/testsuite/gcc.target/powerpc/const-build.c > +++ b/gcc/testsuite/gcc.target/powerpc/const-build.c > @@ -34,14 +34,28 @@ li_rotldi_4 (void) > return 0x21ffffffffffff94LL; > } > > +long long NOIPA > +lis_rotldi_5 (void) > +{ > + return 0xffff85310000ffffLL; > +} > + > +long long NOIPA > +lis_rotldi_6 (void) > +{ > + return 0x5310000ffffffff8LL; > +} > + > struct fun arr[] = { > {li_rotldi_1, 0x7531000000000LL}, > {li_rotldi_2, 0x2100000000000064LL}, > {li_rotldi_3, 0xffff8531ffffffffLL}, > {li_rotldi_4, 0x21ffffffffffff94LL}, > + {lis_rotldi_5, 0xffff85310000ffffLL}, > + {lis_rotldi_6, 0x5310000ffffffff8LL}, > }; > > -/* { dg-final { scan-assembler-times {\mrotldi\M} 4 } } */ > +/* { dg-final { scan-assembler-times {\mrotldi\M} 6 } } */ > > int > main () > -- > 2.39.1 > >
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc index 1dd0072350a..03cd9d5e952 100644 --- a/gcc/config/rs6000/rs6000.cc +++ b/gcc/config/rs6000/rs6000.cc @@ -10278,19 +10278,51 @@ can_be_rotated_to_negative_li (HOST_WIDE_INT c, int *rot) return can_be_rotated_to_lowbits (~c, 15, rot); } -/* Check if value C can be built by 2 instructions: one is 'li', another is - rotldi. +/* Check if C can be rotated to a negative value which 'lis' instruction is + able to load: 1..1xx0..0. If so, set *ROT to the number by which C is + rotated, and return true. Return false otherwise. */ + +static bool +can_be_rotated_to_negative_lis (HOST_WIDE_INT c, int *rot) +{ + /* case a. 1..1xxx0..01..1: up to 15 x's, at least 16 0's. */ + int leading_ones = clz_hwi (~c); + int tailing_ones = ctz_hwi (~c); + int middle_zeros = ctz_hwi (c >> tailing_ones); + if (middle_zeros >= 16 && leading_ones + tailing_ones >= 33) + { + *rot = HOST_BITS_PER_WIDE_INT - tailing_ones; + return true; + } + + /* case b. xx0..01..1xx: some of 15 x's (and some of 16 0's) are + rotated over the highest bit. */ + int pos_one = clz_hwi ((c << 16) >> 16); + middle_zeros = ctz_hwi (c >> (HOST_BITS_PER_WIDE_INT - pos_one)); + int middle_ones = clz_hwi (~(c << pos_one)); + if (middle_zeros >= 16 && middle_ones >= 33) + { + *rot = pos_one; + return true; + } + + return false; +} + +/* Check if value C can be built by 2 instructions: one is 'li or lis', + another is rotldi. If so, *SHIFT is set to the shift operand of rotldi(rldicl), and *MASK is set to -1, and return true. Return false otherwise. */ static bool -can_be_built_by_li_and_rotldi (HOST_WIDE_INT c, int *shift, +can_be_built_by_li_lis_and_rotldi (HOST_WIDE_INT c, int *shift, HOST_WIDE_INT *mask) { int n; if (can_be_rotated_to_positive_li (c, &n) - || can_be_rotated_to_negative_li (c, &n)) + || can_be_rotated_to_negative_li (c, &n) + || can_be_rotated_to_negative_lis (c, &n)) { *mask = HOST_WIDE_INT_M1; *shift = HOST_BITS_PER_WIDE_INT - n; @@ -10346,7 +10378,7 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c) emit_move_insn (dest, gen_rtx_XOR (DImode, temp, GEN_INT ((ud2 ^ 0xffff) << 16))); } - else if (can_be_built_by_li_and_rotldi (c, &shift, &mask)) + else if (can_be_built_by_li_lis_and_rotldi (c, &shift, &mask)) { temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode); unsigned HOST_WIDE_INT imm = (c | ~mask); diff --git a/gcc/testsuite/gcc.target/powerpc/const-build.c b/gcc/testsuite/gcc.target/powerpc/const-build.c index 70f095f6bf2..c38a1dd91f2 100644 --- a/gcc/testsuite/gcc.target/powerpc/const-build.c +++ b/gcc/testsuite/gcc.target/powerpc/const-build.c @@ -34,14 +34,28 @@ li_rotldi_4 (void) return 0x21ffffffffffff94LL; } +long long NOIPA +lis_rotldi_5 (void) +{ + return 0xffff85310000ffffLL; +} + +long long NOIPA +lis_rotldi_6 (void) +{ + return 0x5310000ffffffff8LL; +} + struct fun arr[] = { {li_rotldi_1, 0x7531000000000LL}, {li_rotldi_2, 0x2100000000000064LL}, {li_rotldi_3, 0xffff8531ffffffffLL}, {li_rotldi_4, 0x21ffffffffffff94LL}, + {lis_rotldi_5, 0xffff85310000ffffLL}, + {lis_rotldi_6, 0x5310000ffffffff8LL}, }; -/* { dg-final { scan-assembler-times {\mrotldi\M} 4 } } */ +/* { dg-final { scan-assembler-times {\mrotldi\M} 6 } } */ int main ()
Hi, This patch checks if a constant is possible to be rotated to/from a negative value from "lis". If so, we could use "lis;rotldi" to build it. The positive value of "lis" does not need to be analyzed. Because if a constant can be rotated from the positive value of "lis", it also can be rotated from a positive value of "li". Bootstrap and regtest pass on ppc64{,le}. Is this ok for trunk? BR, Jeff (Jiufu) gcc/ChangeLog: * config/rs6000/rs6000.cc (can_be_rotated_to_negative_lis): New function. (can_be_built_by_li_and_rotldi): Rename to ... (can_be_built_by_li_lis_and_rotldi): ... this function. (rs6000_emit_set_long_const): Call can_be_built_by_li_lis_and_rotldi. gcc/testsuite/ChangeLog: * gcc.target/powerpc/const-build.c: Add more tests. --- gcc/config/rs6000/rs6000.cc | 42 ++++++++++++++++--- .../gcc.target/powerpc/const-build.c | 16 ++++++- 2 files changed, 52 insertions(+), 6 deletions(-)