[PATCH 2/5] gimple-match: Add a gimple_extract_op function

Richard Biener richard.guenther@gmail.com
Fri Nov 19 09:13:22 GMT 2021


On Thu, Nov 18, 2021 at 8:01 PM Richard Sandiford
<richard.sandiford@arm.com> wrote:
>
> Richard Biener <richard.guenther@gmail.com> writes:
> > On Tue, Nov 16, 2021 at 4:51 PM Richard Sandiford
> > <richard.sandiford@arm.com> wrote:
> >>
> >> Richard Biener <richard.guenther@gmail.com> writes:
> >> > On Wed, Nov 10, 2021 at 1:46 PM Richard Sandiford via Gcc-patches
> >> > <gcc-patches@gcc.gnu.org> wrote:
> >> >>
> >> >> code_helper and gimple_match_op seem like generally useful ways
> >> >> of summing up a gimple_assign or gimple_call (or gimple_cond).
> >> >> This patch adds a gimple_extract_op function that can be used
> >> >> for that.
> >> >>
> >> >> Tested on aarch64-linux-gnu and x86_64-linux-gnu.  OK to install?
> >> >>
> >> >> Richard
> >> >>
> >> >>
> >> >> gcc/
> >> >>         * gimple-match.h (gimple_extract_op): Declare.
> >> >>         * gimple-match.c (gimple_extract): New function, extracted from...
> >> >>         (gimple_simplify): ...here.
> >> >>         (gimple_extract_op): New function.
> >> >> ---
> >> >>  gcc/gimple-match-head.c | 261 +++++++++++++++++++++++-----------------
> >> >>  gcc/gimple-match.h      |   1 +
> >> >>  2 files changed, 149 insertions(+), 113 deletions(-)
> >> >>
> >> >> diff --git a/gcc/gimple-match-head.c b/gcc/gimple-match-head.c
> >> >> index 9d88b2f8551..4c6e0883ba4 100644
> >> >> --- a/gcc/gimple-match-head.c
> >> >> +++ b/gcc/gimple-match-head.c
> >> >> @@ -890,12 +890,29 @@ try_conditional_simplification (internal_fn ifn, gimple_match_op *res_op,
> >> >>    return true;
> >> >>  }
> >> >>
> >> >> -/* The main STMT based simplification entry.  It is used by the fold_stmt
> >> >> -   and the fold_stmt_to_constant APIs.  */
> >> >> +/* Common subroutine of gimple_extract_op and gimple_simplify.  Try to
> >> >> +   describe STMT in RES_OP.  Return:
> >> >>
> >> >> -bool
> >> >> -gimple_simplify (gimple *stmt, gimple_match_op *res_op, gimple_seq *seq,
> >> >> -                tree (*valueize)(tree), tree (*top_valueize)(tree))
> >> >> +   - -1 if extraction failed
> >> >> +   - otherwise, 0 if no simplification should take place
> >> >> +   - otherwise, the number of operands for a GIMPLE_ASSIGN or GIMPLE_COND
> >> >> +   - otherwise, -2 for a GIMPLE_CALL
> >> >> +
> >> >> +   Before recording an operand, call:
> >> >> +
> >> >> +   - VALUEIZE_CONDITION for a COND_EXPR condition
> >> >> +   - VALUEIZE_NAME if the rhs of a GIMPLE_ASSIGN is an SSA_NAME
> >> >
> >> > I think at least VALUEIZE_NAME is unnecessary, see below
> >>
> >> Yeah, it's unnecessary.  The idea was to (try to) ensure that
> >> gimple_simplify keeps all the microoptimisations that it had
> >> previously.  This includes open-coding do_valueize for SSA_NAMEs
> >> and jumping straight to the right gimplify_resimplifyN routine
> >> when the number of operands is already known.
> >>
> >> (The two calls to gimple_extract<> produce different functions
> >> that ought to get inlined into their single callers.  A lot of the
> >> jumps should then be threaded.)
> >>
> >> I can drop all that if you don't think it's worth it though.
> >> Just wanted to double-check first.
> >
> > Yes, I'd prefer the simpler and more understandable variant.
>
> Fair :-)  How does this look?  I pulled in the extra conversions
> you mentioned in the later review since they're useful for the
> new gimple_simplify routine.

OK.

Thanks,
Richard.

> Tested as before.
>
> Richard
>
>
> gcc/
>         * gimple-match.h (code_helper): Add functions for querying whether
>         the code represents an internal_fn or a built_in_function.
>         Provide explicit conversion operators for both cases.
>         (gimple_extract_op): Declare.
>         * gimple-match-head.c (gimple_extract): New function, extracted from...
>         (gimple_simplify): ...here.
>         (gimple_extract_op): New function.
> ---
>  gcc/gimple-match-head.c | 218 ++++++++++++++++++++--------------------
>  gcc/gimple-match.h      |  27 +++++
>  2 files changed, 135 insertions(+), 110 deletions(-)
>
> diff --git a/gcc/gimple-match-head.c b/gcc/gimple-match-head.c
> index 9d88b2f8551..15053d1189e 100644
> --- a/gcc/gimple-match-head.c
> +++ b/gcc/gimple-match-head.c
> @@ -890,12 +890,20 @@ try_conditional_simplification (internal_fn ifn, gimple_match_op *res_op,
>    return true;
>  }
>
> -/* The main STMT based simplification entry.  It is used by the fold_stmt
> -   and the fold_stmt_to_constant APIs.  */
> +/* Common subroutine of gimple_extract_op and gimple_simplify.  Try to
> +   describe STMT in RES_OP, returning true on success.  Before recording
> +   an operand, call:
>
> -bool
> -gimple_simplify (gimple *stmt, gimple_match_op *res_op, gimple_seq *seq,
> -                tree (*valueize)(tree), tree (*top_valueize)(tree))
> +   - VALUEIZE_CONDITION for a COND_EXPR condition
> +   - VALUEIZE_OP for every other top-level operand
> +
> +   Both routines take a tree argument and returns a tree.  */
> +
> +template<typename ValueizeOp, typename ValueizeCondition>
> +inline bool
> +gimple_extract (gimple *stmt, gimple_match_op *res_op,
> +               ValueizeOp valueize_op,
> +               ValueizeCondition valueize_condition)
>  {
>    switch (gimple_code (stmt))
>      {
> @@ -911,100 +919,50 @@ gimple_simplify (gimple *stmt, gimple_match_op *res_op, gimple_seq *seq,
>                 || code == VIEW_CONVERT_EXPR)
>               {
>                 tree op0 = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0);
> -               bool valueized = false;
> -               op0 = do_valueize (op0, top_valueize, valueized);
> -               res_op->set_op (code, type, op0);
> -               return (gimple_resimplify1 (seq, res_op, valueize)
> -                       || valueized);
> +               res_op->set_op (code, type, valueize_op (op0));
> +               return true;
>               }
>             else if (code == BIT_FIELD_REF)
>               {
>                 tree rhs1 = gimple_assign_rhs1 (stmt);
> -               tree op0 = TREE_OPERAND (rhs1, 0);
> -               bool valueized = false;
> -               op0 = do_valueize (op0, top_valueize, valueized);
> +               tree op0 = valueize_op (TREE_OPERAND (rhs1, 0));
>                 res_op->set_op (code, type, op0,
>                                 TREE_OPERAND (rhs1, 1),
>                                 TREE_OPERAND (rhs1, 2),
>                                 REF_REVERSE_STORAGE_ORDER (rhs1));
> -               if (res_op->reverse)
> -                 return valueized;
> -               return (gimple_resimplify3 (seq, res_op, valueize)
> -                       || valueized);
> +               return true;
>               }
> -           else if (code == SSA_NAME
> -                    && top_valueize)
> +           else if (code == SSA_NAME)
>               {
>                 tree op0 = gimple_assign_rhs1 (stmt);
> -               tree valueized = top_valueize (op0);
> -               if (!valueized || op0 == valueized)
> -                 return false;
> -               res_op->set_op (TREE_CODE (op0), type, valueized);
> +               res_op->set_op (TREE_CODE (op0), type, valueize_op (op0));
>                 return true;
>               }
>             break;
>           case GIMPLE_UNARY_RHS:
>             {
>               tree rhs1 = gimple_assign_rhs1 (stmt);
> -             bool valueized = false;
> -             rhs1 = do_valueize (rhs1, top_valueize, valueized);
> -             res_op->set_op (code, type, rhs1);
> -             return (gimple_resimplify1 (seq, res_op, valueize)
> -                     || valueized);
> +             res_op->set_op (code, type, valueize_op (rhs1));
> +             return true;
>             }
>           case GIMPLE_BINARY_RHS:
>             {
> -             tree rhs1 = gimple_assign_rhs1 (stmt);
> -             tree rhs2 = gimple_assign_rhs2 (stmt);
> -             bool valueized = false;
> -             rhs1 = do_valueize (rhs1, top_valueize, valueized);
> -             rhs2 = do_valueize (rhs2, top_valueize, valueized);
> +             tree rhs1 = valueize_op (gimple_assign_rhs1 (stmt));
> +             tree rhs2 = valueize_op (gimple_assign_rhs2 (stmt));
>               res_op->set_op (code, type, rhs1, rhs2);
> -             return (gimple_resimplify2 (seq, res_op, valueize)
> -                     || valueized);
> +             return true;
>             }
>           case GIMPLE_TERNARY_RHS:
>             {
> -             bool valueized = false;
>               tree rhs1 = gimple_assign_rhs1 (stmt);
> -             /* If this is a COND_EXPR first try to simplify an
> -                embedded GENERIC condition.  */
> -             if (code == COND_EXPR)
> -               {
> -                 if (COMPARISON_CLASS_P (rhs1))
> -                   {
> -                     tree lhs = TREE_OPERAND (rhs1, 0);
> -                     tree rhs = TREE_OPERAND (rhs1, 1);
> -                     lhs = do_valueize (lhs, top_valueize, valueized);
> -                     rhs = do_valueize (rhs, top_valueize, valueized);
> -                     gimple_match_op res_op2 (res_op->cond, TREE_CODE (rhs1),
> -                                              TREE_TYPE (rhs1), lhs, rhs);
> -                     if ((gimple_resimplify2 (seq, &res_op2, valueize)
> -                          || valueized)
> -                         && res_op2.code.is_tree_code ())
> -                       {
> -                         valueized = true;
> -                         if (TREE_CODE_CLASS ((enum tree_code) res_op2.code)
> -                             == tcc_comparison)
> -                           rhs1 = build2 (res_op2.code, TREE_TYPE (rhs1),
> -                                          res_op2.ops[0], res_op2.ops[1]);
> -                         else if (res_op2.code == SSA_NAME
> -                                  || res_op2.code == INTEGER_CST
> -                                  || res_op2.code == VECTOR_CST)
> -                           rhs1 = res_op2.ops[0];
> -                         else
> -                           valueized = false;
> -                       }
> -                   }
> -               }
> -             tree rhs2 = gimple_assign_rhs2 (stmt);
> -             tree rhs3 = gimple_assign_rhs3 (stmt);
> -             rhs1 = do_valueize (rhs1, top_valueize, valueized);
> -             rhs2 = do_valueize (rhs2, top_valueize, valueized);
> -             rhs3 = do_valueize (rhs3, top_valueize, valueized);
> +             if (code == COND_EXPR && COMPARISON_CLASS_P (rhs1))
> +               rhs1 = valueize_condition (rhs1);
> +             else
> +               rhs1 = valueize_op (rhs1);
> +             tree rhs2 = valueize_op (gimple_assign_rhs2 (stmt));
> +             tree rhs3 = valueize_op (gimple_assign_rhs3 (stmt));
>               res_op->set_op (code, type, rhs1, rhs2, rhs3);
> -             return (gimple_resimplify3 (seq, res_op, valueize)
> -                     || valueized);
> +             return true;
>             }
>           default:
>             gcc_unreachable ();
> @@ -1018,7 +976,6 @@ gimple_simplify (gimple *stmt, gimple_match_op *res_op, gimple_seq *seq,
>           && gimple_call_num_args (stmt) >= 1
>           && gimple_call_num_args (stmt) <= 5)
>         {
> -         bool valueized = false;
>           combined_fn cfn;
>           if (gimple_call_internal_p (stmt))
>             cfn = as_combined_fn (gimple_call_internal_fn (stmt));
> @@ -1028,7 +985,7 @@ gimple_simplify (gimple *stmt, gimple_match_op *res_op, gimple_seq *seq,
>               if (!fn)
>                 return false;
>
> -             fn = do_valueize (fn, top_valueize, valueized);
> +             fn = valueize_op (fn);
>               if (TREE_CODE (fn) != ADDR_EXPR
>                   || TREE_CODE (TREE_OPERAND (fn, 0)) != FUNCTION_DECL)
>                 return false;
> @@ -1044,47 +1001,17 @@ gimple_simplify (gimple *stmt, gimple_match_op *res_op, gimple_seq *seq,
>           unsigned int num_args = gimple_call_num_args (stmt);
>           res_op->set_op (cfn, TREE_TYPE (gimple_call_lhs (stmt)), num_args);
>           for (unsigned i = 0; i < num_args; ++i)
> -           {
> -             tree arg = gimple_call_arg (stmt, i);
> -             res_op->ops[i] = do_valueize (arg, top_valueize, valueized);
> -           }
> -         if (internal_fn_p (cfn)
> -             && try_conditional_simplification (as_internal_fn (cfn),
> -                                                res_op, seq, valueize))
> -           return true;
> -         switch (num_args)
> -           {
> -           case 1:
> -             return (gimple_resimplify1 (seq, res_op, valueize)
> -                     || valueized);
> -           case 2:
> -             return (gimple_resimplify2 (seq, res_op, valueize)
> -                     || valueized);
> -           case 3:
> -             return (gimple_resimplify3 (seq, res_op, valueize)
> -                     || valueized);
> -           case 4:
> -             return (gimple_resimplify4 (seq, res_op, valueize)
> -                     || valueized);
> -           case 5:
> -             return (gimple_resimplify5 (seq, res_op, valueize)
> -                     || valueized);
> -           default:
> -            gcc_unreachable ();
> -           }
> +           res_op->ops[i] = valueize_op (gimple_call_arg (stmt, i));
> +         return true;
>         }
>        break;
>
>      case GIMPLE_COND:
>        {
> -       tree lhs = gimple_cond_lhs (stmt);
> -       tree rhs = gimple_cond_rhs (stmt);
> -       bool valueized = false;
> -       lhs = do_valueize (lhs, top_valueize, valueized);
> -       rhs = do_valueize (rhs, top_valueize, valueized);
> +       tree lhs = valueize_op (gimple_cond_lhs (stmt));
> +       tree rhs = valueize_op (gimple_cond_rhs (stmt));
>         res_op->set_op (gimple_cond_code (stmt), boolean_type_node, lhs, rhs);
> -       return (gimple_resimplify2 (seq, res_op, valueize)
> -               || valueized);
> +       return true;
>        }
>
>      default:
> @@ -1094,6 +1021,77 @@ gimple_simplify (gimple *stmt, gimple_match_op *res_op, gimple_seq *seq,
>    return false;
>  }
>
> +/* Try to describe STMT in RES_OP, returning true on success.
> +   For GIMPLE_CONDs, describe the condition that is being tested.
> +   For GIMPLE_ASSIGNs, describe the rhs of the assignment.
> +   For GIMPLE_CALLs, describe the call.  */
> +
> +bool
> +gimple_extract_op (gimple *stmt, gimple_match_op *res_op)
> +{
> +  auto nop = [](tree op) { return op; };
> +  return gimple_extract (stmt, res_op, nop, nop);
> +}
> +
> +/* The main STMT based simplification entry.  It is used by the fold_stmt
> +   and the fold_stmt_to_constant APIs.  */
> +
> +bool
> +gimple_simplify (gimple *stmt, gimple_match_op *res_op, gimple_seq *seq,
> +                tree (*valueize)(tree), tree (*top_valueize)(tree))
> +{
> +  bool valueized = false;
> +  auto valueize_op = [&](tree op)
> +    {
> +      return do_valueize (op, top_valueize, valueized);
> +    };
> +  auto valueize_condition = [&](tree op) -> tree
> +    {
> +      bool cond_valueized = false;
> +      tree lhs = do_valueize (TREE_OPERAND (op, 0), top_valueize,
> +                             cond_valueized);
> +      tree rhs = do_valueize (TREE_OPERAND (op, 1), top_valueize,
> +                             cond_valueized);
> +      gimple_match_op res_op2 (res_op->cond, TREE_CODE (op),
> +                              TREE_TYPE (op), lhs, rhs);
> +      if ((gimple_resimplify2 (seq, &res_op2, valueize)
> +          || cond_valueized)
> +         && res_op2.code.is_tree_code ())
> +       {
> +         if (TREE_CODE_CLASS ((tree_code) res_op2.code) == tcc_comparison)
> +           {
> +             valueized = true;
> +             return build2 (res_op2.code, TREE_TYPE (op),
> +                            res_op2.ops[0], res_op2.ops[1]);
> +           }
> +         else if (res_op2.code == SSA_NAME
> +                  || res_op2.code == INTEGER_CST
> +                  || res_op2.code == VECTOR_CST)
> +           {
> +             valueized = true;
> +             return res_op2.ops[0];
> +           }
> +       }
> +      return valueize_op (op);
> +    };
> +
> +  if (!gimple_extract (stmt, res_op, valueize_op, valueize_condition))
> +    return false;
> +
> +  if (res_op->code.is_internal_fn ())
> +    {
> +      internal_fn ifn = internal_fn (res_op->code);
> +      if (try_conditional_simplification (ifn, res_op, seq, valueize))
> +       return true;
> +    }
> +
> +  if (!res_op->reverse
> +      && res_op->num_ops
> +      && res_op->resimplify (seq, valueize))
> +    return true;
> +
> +  return valueized;
> +}
>
>  /* Helper for the autogenerated code, valueize OP.  */
>
> diff --git a/gcc/gimple-match.h b/gcc/gimple-match.h
> index 2d4ea476076..8abeafebb00 100644
> --- a/gcc/gimple-match.h
> +++ b/gcc/gimple-match.h
> @@ -33,13 +33,39 @@ public:
>    code_helper (combined_fn fn) : rep (-(int) fn) {}
>    operator tree_code () const { return (tree_code) rep; }
>    operator combined_fn () const { return (combined_fn) -rep; }
> +  explicit operator internal_fn () const;
> +  explicit operator built_in_function () const;
>    bool is_tree_code () const { return rep > 0; }
>    bool is_fn_code () const { return rep < 0; }
> +  bool is_internal_fn () const;
> +  bool is_builtin_fn () const;
>    int get_rep () const { return rep; }
>  private:
>    int rep;
>  };
>
> +inline code_helper::operator internal_fn () const
> +{
> +  return as_internal_fn (combined_fn (*this));
> +}
> +
> +inline code_helper::operator built_in_function () const
> +{
> +  return as_builtin_fn (combined_fn (*this));
> +}
> +
> +inline bool
> +code_helper::is_internal_fn () const
> +{
> +  return is_fn_code () && internal_fn_p (combined_fn (*this));
> +}
> +
> +inline bool
> +code_helper::is_builtin_fn () const
> +{
> +  return is_fn_code () && builtin_fn_p (combined_fn (*this));
> +}
> +
>  /* Represents the condition under which an operation should happen,
>     and the value to use otherwise.  The condition applies elementwise
>     (as for VEC_COND_EXPR) if the values are vectors.  */
> @@ -333,6 +359,7 @@ gimple_simplified_result_is_gimple_val (const gimple_match_op *op)
>
>  extern tree (*mprts_hook) (gimple_match_op *);
>
> +bool gimple_extract_op (gimple *, gimple_match_op *);
>  bool gimple_simplify (gimple *, gimple_match_op *, gimple_seq *,
>                       tree (*)(tree), tree (*)(tree));
>  tree maybe_push_res_to_seq (gimple_match_op *, gimple_seq *,
> --
> 2.25.1
>


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