Hi Richard,

I updated patch according to all your comments.
Also bootstrapped and tested again on x86_64-pc-linux-gnu and aarch64-linux-gnu, which took some time.

attached v3.

Thanks,
Dmitrij

On Thu, Sep 26, 2019 at 09:47:04AM +0200, Richard Biener wrote:
> On Tue, Sep 24, 2019 at 5:29 PM Dmitrij Pochepko
> <dmitrij.pochepko@bell-sw.com> wrote:
> >
> > Hi,
> >
> > can anybody take a look at v2?
> 
> +    (if (tree_to_uhwi (@4) == 1
> +         && tree_to_uhwi (@10) == 2 && tree_to_uhwi (@5) == 4
> 
> those will still ICE for large __int128_t constants.  Since you do not match
> any conversions you should probably restrict the precision of 'type' like
> with
>    (if (TYPE_PRECISION (type) <= 64
>         && tree_to_uhwi (@4) ...
> 
> likewise tree_to_uhwi will fail for negative constants thus if the
> pattern assumes
> unsigned you should verify that as well with && TYPE_UNSIGNED  (type).
> 
> Your 'argtype' is simply 'type' so you can elide it.
> 
> +       (switch
> +           (if (types_match (argtype, long_long_unsigned_type_node))
> +             (convert (BUILT_IN_POPCOUNTLL:integer_type_node @0)))
> +           (if (types_match (argtype, long_unsigned_type_node))
> +             (convert (BUILT_IN_POPCOUNTL:integer_type_node @0)))
> +           (if (types_match (argtype, unsigned_type_node))
> +             (convert (BUILT_IN_POPCOUNT:integer_type_node @0)))))))
> 
> Please test small types first so we can avoid popcountll when long == long long
> or long == int.  I also wonder if we really want to use the builtins and
> check optab availability or if we nowadays should use
> direct_internal_fn_supported_p (IFN_POPCOUNT, integer_type_node, type,
> OPTIMIZE_FOR_BOTH) and
> 
>     (convert (IFN_POPCOUNT:type @0))
> 
> without the switch?
> 
> Thanks,
> Richard.
> 
> > Thanks,
> > Dmitrij
> >
> > On Mon, Sep 09, 2019 at 10:03:40PM +0300, Dmitrij Pochepko wrote:
> > > Hi all.
> > >
> > > Please take a look at v2 (attached).
> > > I changed patch according to review comments. The same testing was performed again.
> > >
> > > Thanks,
> > > Dmitrij
> > >
> > > On Thu, Sep 05, 2019 at 06:34:49PM +0300, Dmitrij Pochepko wrote:
> > > > This patch adds matching for Hamming weight (popcount) implementation. The following sources:
> > > >
> > > > int
> > > > foo64 (unsigned long long a)
> > > > {
> > > >     unsigned long long b = a;
> > > >     b -= ((b>>1) & 0x5555555555555555ULL);
> > > >     b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
> > > >     b = ((b>>4) + b) & 0x0F0F0F0F0F0F0F0FULL;
> > > >     b *= 0x0101010101010101ULL;
> > > >     return (int)(b >> 56);
> > > > }
> > > >
> > > > and
> > > >
> > > > int
> > > > foo32 (unsigned int a)
> > > > {
> > > >     unsigned long b = a;
> > > >     b -= ((b>>1) & 0x55555555UL);
> > > >     b = ((b>>2) & 0x33333333UL) + (b & 0x33333333UL);
> > > >     b = ((b>>4) + b) & 0x0F0F0F0FUL;
> > > >     b *= 0x01010101UL;
> > > >     return (int)(b >> 24);
> > > > }
> > > >
> > > > and equivalents are now recognized as popcount for platforms with hw popcount support. Bootstrapped and tested on x86_64-pc-linux-gnu and aarch64-linux-gnu systems with no regressions.
> > > >
> > > > (I have no write access to repo)
> > > >
> > > > Thanks,
> > > > Dmitrij
> > > >
> > > >
> > > > gcc/ChangeLog:
> > > >
> > > >     PR tree-optimization/90836
> > > >
> > > >     * gcc/match.pd (popcount): New pattern.
> > > >
> > > > gcc/testsuite/ChangeLog:
> > > >
> > > >     PR tree-optimization/90836
> > > >
> > > >     * lib/target-supports.exp (check_effective_target_popcount)
> > > >     (check_effective_target_popcountll): New effective targets.
> > > >     * gcc.dg/tree-ssa/popcount4.c: New test.
> > > >     * gcc.dg/tree-ssa/popcount4l.c: New test.
> > > >     * gcc.dg/tree-ssa/popcount4ll.c: New test.
> > >
> > > > diff --git a/gcc/match.pd b/gcc/match.pd
> > > > index 0317bc7..b1867bf 100644
> > > > --- a/gcc/match.pd
> > > > +++ b/gcc/match.pd
> > > > @@ -5358,6 +5358,70 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> > > >        (cmp (popcount @0) integer_zerop)
> > > >        (rep @0 { build_zero_cst (TREE_TYPE (@0)); }))))
> > > >
> > > > +/* 64- and 32-bits branchless implementations of popcount are detected:
> > > > +
> > > > +   int popcount64c (uint64_t x)
> > > > +   {
> > > > +     x -= (x >> 1) & 0x5555555555555555ULL;
> > > > +     x = (x & 0x3333333333333333ULL) + ((x >> 2) & 0x3333333333333333ULL);
> > > > +     x = (x + (x >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
> > > > +     return (x * 0x0101010101010101ULL) >> 56;
> > > > +   }
> > > > +
> > > > +   int popcount32c (uint32_t x)
> > > > +   {
> > > > +     x -= (x >> 1) & 0x55555555;
> > > > +     x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
> > > > +     x = (x + (x >> 4)) & 0x0f0f0f0f;
> > > > +     return (x * 0x01010101) >> 24;
> > > > +   }  */
> > > > +(simplify
> > > > +  (convert
> > > > +    (rshift
> > > > +      (mult
> > > > +   (bit_and:c
> > > > +     (plus:c
> > > > +       (rshift @8 INTEGER_CST@5)
> > > > +       (plus:c@8
> > > > +         (bit_and @6 INTEGER_CST@7)
> > > > +         (bit_and
> > > > +           (rshift
> > > > +             (minus@6
> > > > +               @0
> > > > +               (bit_and
> > > > +                 (rshift @0 INTEGER_CST@4)
> > > > +                 INTEGER_CST@11))
> > > > +             INTEGER_CST@10)
> > > > +           INTEGER_CST@9)))
> > > > +     INTEGER_CST@3)
> > > > +   INTEGER_CST@2)
> > > > +      INTEGER_CST@1))
> > > > +  /* Check constants and optab.  */
> > > > +  (with
> > > > +     {
> > > > +       tree argtype = TREE_TYPE (@0);
> > > > +       unsigned prec = TYPE_PRECISION (argtype);
> > > > +       int shift = TYPE_PRECISION (long_long_unsigned_type_node) - prec;
> > > > +       const unsigned long long c1 = 0x0101010101010101ULL >> shift,
> > > > +                           c2 = 0x0F0F0F0F0F0F0F0FULL >> shift,
> > > > +                           c3 = 0x3333333333333333ULL >> shift,
> > > > +                           c4 = 0x5555555555555555ULL >> shift;
> > > > +     }
> > > > +    (if (types_match (type, integer_type_node) && tree_to_uhwi (@4) == 1
> > > > +     && tree_to_uhwi (@10) == 2 && tree_to_uhwi (@5) == 4
> > > > +     && tree_to_uhwi (@1) == prec - 8 && tree_to_uhwi (@2) == c1
> > > > +     && tree_to_uhwi (@3) == c2 && tree_to_uhwi (@9) == c3
> > > > +     && tree_to_uhwi (@7) == c3 && tree_to_uhwi (@11) == c4
> > > > +     && optab_handler (popcount_optab, TYPE_MODE (argtype))
> > > > +       != CODE_FOR_nothing)
> > > > +   (switch
> > > > +       (if (types_match (argtype, long_long_unsigned_type_node))
> > > > +         (BUILT_IN_POPCOUNTLL @0))
> > > > +       (if (types_match (argtype, long_unsigned_type_node))
> > > > +         (BUILT_IN_POPCOUNTL @0))
> > > > +       (if (types_match (argtype, unsigned_type_node))
> > > > +         (BUILT_IN_POPCOUNT @0))))))
> > > > +
> > > >  /* Simplify:
> > > >
> > > >       a = a1 op a2
> > > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount4.c b/gcc/testsuite/gcc.dg/tree-ssa/popcount4.c
> > > > new file mode 100644
> > > > index 0000000..9f759f8
> > > > --- /dev/null
> > > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount4.c
> > > > @@ -0,0 +1,22 @@
> > > > +/* { dg-do compile } */
> > > > +/* { dg-require-effective-target popcount } */
> > > > +/* { dg-require-effective-target int32plus } */
> > > > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > > > +
> > > > +const unsigned m1  = 0x55555555UL;
> > > > +const unsigned m2  = 0x33333333UL;
> > > > +const unsigned m4  = 0x0F0F0F0FUL;
> > > > +const unsigned h01 = 0x01010101UL;
> > > > +const int shift = 24;
> > > > +
> > > > +int popcount64c(unsigned x)
> > > > +{
> > > > +    x -= (x >> 1) & m1;
> > > > +    x = (x & m2) + ((x >> 2) & m2);
> > > > +    x = (x + (x >> 4)) & m4;
> > > > +    return (x * h01) >> shift;
> > > > +}
> > > > +
> > > > +/* { dg-final { scan-tree-dump-times "__builtin_popcount" 1 "optimized" } } */
> > > > +
> > > > +
> > > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount4l.c b/gcc/testsuite/gcc.dg/tree-ssa/popcount4l.c
> > > > new file mode 100644
> > > > index 0000000..ab33f79
> > > > --- /dev/null
> > > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount4l.c
> > > > @@ -0,0 +1,30 @@
> > > > +/* { dg-do compile } */
> > > > +/* { dg-require-effective-target popcountl } */
> > > > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > > > +
> > > > +#if __SIZEOF_LONG__ == 4
> > > > +const unsigned long m1  = 0x55555555UL;
> > > > +const unsigned long m2  = 0x33333333UL;
> > > > +const unsigned long m4  = 0x0F0F0F0FUL;
> > > > +const unsigned long h01 = 0x01010101UL;
> > > > +const int shift = 24;
> > > > +#else
> > > > +const unsigned long m1  = 0x5555555555555555UL;
> > > > +const unsigned long m2  = 0x3333333333333333UL;
> > > > +const unsigned long m4  = 0x0f0f0f0f0f0f0f0fUL;
> > > > +const unsigned long h01 = 0x0101010101010101UL;
> > > > +const int shift = 56;
> > > > +#endif
> > > > +
> > > > +
> > > > +int popcount64c(unsigned long x)
> > > > +{
> > > > +    x -= (x >> 1) & m1;
> > > > +    x = (x & m2) + ((x >> 2) & m2);
> > > > +    x = (x + (x >> 4)) & m4;
> > > > +    return (x * h01) >> shift;
> > > > +}
> > > > +
> > > > +/* { dg-final { scan-tree-dump-times "__builtin_popcountl" 1 "optimized" } } */
> > > > +
> > > > +
> > > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount4ll.c b/gcc/testsuite/gcc.dg/tree-ssa/popcount4ll.c
> > > > new file mode 100644
> > > > index 0000000..f3755f1
> > > > --- /dev/null
> > > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount4ll.c
> > > > @@ -0,0 +1,19 @@
> > > > +/* { dg-do compile } */
> > > > +/* { dg-require-effective-target popcountll } */
> > > > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > > > +
> > > > +const unsigned long long m1  = 0x5555555555555555ULL;
> > > > +const unsigned long long m2  = 0x3333333333333333ULL;
> > > > +const unsigned long long m4  = 0x0F0F0F0F0F0F0F0FULL;
> > > > +const unsigned long long h01 = 0x0101010101010101ULL;
> > > > +const int shift = 56;
> > > > +
> > > > +int popcount64c(unsigned long long x)
> > > > +{
> > > > +    x -= (x >> 1) & m1;
> > > > +    x = (x & m2) + ((x >> 2) & m2);
> > > > +    x = (x + (x >> 4)) & m4;
> > > > +    return (x * h01) >> shift;
> > > > +}
> > > > +
> > > > +/* { dg-final { scan-tree-dump-times "__builtin_popcountll" 1 "optimized" } } */
> > > > diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
> > > > index 3c50b89..32bbad7 100644
> > > > --- a/gcc/testsuite/lib/target-supports.exp
> > > > +++ b/gcc/testsuite/lib/target-supports.exp
> > > > @@ -6855,6 +6855,29 @@ proc check_effective_target_popcountl { } {
> > > >      } "" ]
> > > >  }
> > > >
> > > > +# Return 1 if the target supports popcount on long long.
> > > > +
> > > > +proc check_effective_target_popcountll { } {
> > > > +    return [check_no_messages_and_pattern popcountll "!\\(call" rtl-expand {
> > > > +        int foo (long long b)
> > > > +          {
> > > > +            return __builtin_popcountll (b);
> > > > +          }
> > > > +    } "" ]
> > > > +}
> > > > +
> > > > +
> > > > +# Return 1 if the target supports popcount on int.
> > > > +
> > > > +proc check_effective_target_popcount { } {
> > > > +    return [check_no_messages_and_pattern popcount "!\\(call" rtl-expand {
> > > > +        int foo (int b)
> > > > +          {
> > > > +            return __builtin_popcount (b);
> > > > +          }
> > > > +    } "" ]
> > > > +}
> > > > +
> > > >  # Return 1 if the target supports atomic operations on "long long"
> > > >  # and can execute them.
> > > >  #
> > >
> >
> > > diff --git a/gcc/match.pd b/gcc/match.pd
> > > index 0317bc7..896d5b6 100644
> > > --- a/gcc/match.pd
> > > +++ b/gcc/match.pd
> > > @@ -5358,6 +5358,69 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> > >        (cmp (popcount @0) integer_zerop)
> > >        (rep @0 { build_zero_cst (TREE_TYPE (@0)); }))))
> > >
> > > +/* 64- and 32-bits branchless implementations of popcount are detected:
> > > +
> > > +   int popcount64c (uint64_t x)
> > > +   {
> > > +     x -= (x >> 1) & 0x5555555555555555ULL;
> > > +     x = (x & 0x3333333333333333ULL) + ((x >> 2) & 0x3333333333333333ULL);
> > > +     x = (x + (x >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
> > > +     return (x * 0x0101010101010101ULL) >> 56;
> > > +   }
> > > +
> > > +   int popcount32c (uint32_t x)
> > > +   {
> > > +     x -= (x >> 1) & 0x55555555;
> > > +     x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
> > > +     x = (x + (x >> 4)) & 0x0f0f0f0f;
> > > +     return (x * 0x01010101) >> 24;
> > > +   }  */
> > > +(simplify
> > > +  (rshift
> > > +    (mult
> > > +      (bit_and
> > > +     (plus:c
> > > +       (rshift @8 INTEGER_CST@5)
> > > +       (plus:c@8
> > > +         (bit_and @6 INTEGER_CST@7)
> > > +         (bit_and
> > > +           (rshift
> > > +             (minus@6
> > > +               @0
> > > +               (bit_and
> > > +                 (rshift @0 INTEGER_CST@4)
> > > +                 INTEGER_CST@11))
> > > +           INTEGER_CST@10)
> > > +         INTEGER_CST@9)))
> > > +     INTEGER_CST@3)
> > > +      INTEGER_CST@2)
> > > +    INTEGER_CST@1)
> > > +  /* Check constants and optab.  */
> > > +  (with
> > > +     {
> > > +       tree argtype = TREE_TYPE (@0);
> > > +       unsigned prec = TYPE_PRECISION (argtype);
> > > +       int shift = 64 - prec;
> > > +       const unsigned HOST_WIDE_INT c1 = 0x0101010101010101ULL >> shift,
> > > +                                 c2 = 0x0F0F0F0F0F0F0F0FULL >> shift,
> > > +                                 c3 = 0x3333333333333333ULL >> shift,
> > > +                                 c4 = 0x5555555555555555ULL >> shift;
> > > +     }
> > > +    (if (tree_to_uhwi (@4) == 1
> > > +       && tree_to_uhwi (@10) == 2 && tree_to_uhwi (@5) == 4
> > > +       && tree_to_uhwi (@1) == prec - 8 && tree_to_uhwi (@2) == c1
> > > +       && tree_to_uhwi (@3) == c2 && tree_to_uhwi (@9) == c3
> > > +       && tree_to_uhwi (@7) == c3 && tree_to_uhwi (@11) == c4
> > > +       && optab_handler (popcount_optab, TYPE_MODE (argtype))
> > > +         != CODE_FOR_nothing)
> > > +     (switch
> > > +         (if (types_match (argtype, long_long_unsigned_type_node))
> > > +           (convert (BUILT_IN_POPCOUNTLL:integer_type_node @0)))
> > > +         (if (types_match (argtype, long_unsigned_type_node))
> > > +           (convert (BUILT_IN_POPCOUNTL:integer_type_node @0)))
> > > +         (if (types_match (argtype, unsigned_type_node))
> > > +           (convert (BUILT_IN_POPCOUNT:integer_type_node @0)))))))
> > > +
> > >  /* Simplify:
> > >
> > >       a = a1 op a2
> > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount4.c b/gcc/testsuite/gcc.dg/tree-ssa/popcount4.c
> > > new file mode 100644
> > > index 0000000..9f759f8
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount4.c
> > > @@ -0,0 +1,22 @@
> > > +/* { dg-do compile } */
> > > +/* { dg-require-effective-target popcount } */
> > > +/* { dg-require-effective-target int32plus } */
> > > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > > +
> > > +const unsigned m1  = 0x55555555UL;
> > > +const unsigned m2  = 0x33333333UL;
> > > +const unsigned m4  = 0x0F0F0F0FUL;
> > > +const unsigned h01 = 0x01010101UL;
> > > +const int shift = 24;
> > > +
> > > +int popcount64c(unsigned x)
> > > +{
> > > +    x -= (x >> 1) & m1;
> > > +    x = (x & m2) + ((x >> 2) & m2);
> > > +    x = (x + (x >> 4)) & m4;
> > > +    return (x * h01) >> shift;
> > > +}
> > > +
> > > +/* { dg-final { scan-tree-dump-times "__builtin_popcount" 1 "optimized" } } */
> > > +
> > > +
> > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount4l.c b/gcc/testsuite/gcc.dg/tree-ssa/popcount4l.c
> > > new file mode 100644
> > > index 0000000..ab33f79
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount4l.c
> > > @@ -0,0 +1,30 @@
> > > +/* { dg-do compile } */
> > > +/* { dg-require-effective-target popcountl } */
> > > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > > +
> > > +#if __SIZEOF_LONG__ == 4
> > > +const unsigned long m1  = 0x55555555UL;
> > > +const unsigned long m2  = 0x33333333UL;
> > > +const unsigned long m4  = 0x0F0F0F0FUL;
> > > +const unsigned long h01 = 0x01010101UL;
> > > +const int shift = 24;
> > > +#else
> > > +const unsigned long m1  = 0x5555555555555555UL;
> > > +const unsigned long m2  = 0x3333333333333333UL;
> > > +const unsigned long m4  = 0x0f0f0f0f0f0f0f0fUL;
> > > +const unsigned long h01 = 0x0101010101010101UL;
> > > +const int shift = 56;
> > > +#endif
> > > +
> > > +
> > > +int popcount64c(unsigned long x)
> > > +{
> > > +    x -= (x >> 1) & m1;
> > > +    x = (x & m2) + ((x >> 2) & m2);
> > > +    x = (x + (x >> 4)) & m4;
> > > +    return (x * h01) >> shift;
> > > +}
> > > +
> > > +/* { dg-final { scan-tree-dump-times "__builtin_popcountl" 1 "optimized" } } */
> > > +
> > > +
> > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount4ll.c b/gcc/testsuite/gcc.dg/tree-ssa/popcount4ll.c
> > > new file mode 100644
> > > index 0000000..f3755f1
> > > --- /dev/null
> > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount4ll.c
> > > @@ -0,0 +1,19 @@
> > > +/* { dg-do compile } */
> > > +/* { dg-require-effective-target popcountll } */
> > > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > > +
> > > +const unsigned long long m1  = 0x5555555555555555ULL;
> > > +const unsigned long long m2  = 0x3333333333333333ULL;
> > > +const unsigned long long m4  = 0x0F0F0F0F0F0F0F0FULL;
> > > +const unsigned long long h01 = 0x0101010101010101ULL;
> > > +const int shift = 56;
> > > +
> > > +int popcount64c(unsigned long long x)
> > > +{
> > > +    x -= (x >> 1) & m1;
> > > +    x = (x & m2) + ((x >> 2) & m2);
> > > +    x = (x + (x >> 4)) & m4;
> > > +    return (x * h01) >> shift;
> > > +}
> > > +
> > > +/* { dg-final { scan-tree-dump-times "__builtin_popcountll" 1 "optimized" } } */
> > > diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
> > > index 3c50b89..32bbad7 100644
> > > --- a/gcc/testsuite/lib/target-supports.exp
> > > +++ b/gcc/testsuite/lib/target-supports.exp
> > > @@ -6855,6 +6855,29 @@ proc check_effective_target_popcountl { } {
> > >      } "" ]
> > >  }
> > >
> > > +# Return 1 if the target supports popcount on long long.
> > > +
> > > +proc check_effective_target_popcountll { } {
> > > +    return [check_no_messages_and_pattern popcountll "!\\(call" rtl-expand {
> > > +        int foo (long long b)
> > > +          {
> > > +            return __builtin_popcountll (b);
> > > +          }
> > > +    } "" ]
> > > +}
> > > +
> > > +
> > > +# Return 1 if the target supports popcount on int.
> > > +
> > > +proc check_effective_target_popcount { } {
> > > +    return [check_no_messages_and_pattern popcount "!\\(call" rtl-expand {
> > > +        int foo (int b)
> > > +          {
> > > +            return __builtin_popcount (b);
> > > +          }
> > > +    } "" ]
> > > +}
> > > +
> > >  # Return 1 if the target supports atomic operations on "long long"
> > >  # and can execute them.
> > >  #
> >