On Tue, Nov 16, 2021 at 4:51 PM Richard Sandiford
<richard.sandif...@arm.com> wrote:
>
> Richard Biener <richard.guent...@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.
Richard.
>
> Thanks,
> Richard
>
> >> + - VALUEIZE_OP for every other top-level operand
> >> +
> >> + Each routine takes a tree argument and returns a tree. */
> >> +
> >> +template<typename ValueizeOp, typename ValueizeCondition,
> >> + typename ValueizeName>
> >> +inline int
> >> +gimple_extract (gimple *stmt, gimple_match_op *res_op,
> >> + ValueizeOp valueize_op,
> >> + ValueizeCondition valueize_condition,
> >> + ValueizeName valueize_name)
> >> {
> >> switch (gimple_code (stmt))
> >> {
> >> @@ -911,100 +928,53 @@ 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 1;
> >> }
> >> 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 res_op->reverse ? 0 : 3;
> >> }
> >> - else if (code == SSA_NAME
> >> - && top_valueize)
> >> + else if (code == SSA_NAME)
> >> {
> >> tree op0 = gimple_assign_rhs1 (stmt);
> >> - tree valueized = top_valueize (op0);
> >> + tree valueized = valueize_name (op0);
> >> if (!valueized || op0 == valueized)
> >> - return false;
> >> + return -1;
> >> res_op->set_op (TREE_CODE (op0), type, valueized);
> >> - return true;
> >> + return 0;
> >
> > So the old code in an obfuscated way just knowed nothing simplifies
> > on the plain not valueized name but returned true when valueization
> > changed the stmt. So I'd expect
> >
> > tree valueized = valueize_op (op0);
> > res_op->set_op (TREE_CODE (op0), type, valueized);
> > return 0;
> >
> > here and the gimple_simplify caller returning 'valueized'. I think
> > that the old code treated a NULL top_valueize () as "fail" is just
> > premature optimization without any effect.
> >
> >> }
> >> 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 1;
> >> }
> >> 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 2;
> >> }
> >> 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 3;
> >> }
> >> default:
> >> gcc_unreachable ();
> >> @@ -1018,7 +988,6 @@ 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));
> >> @@ -1026,17 +995,17 @@ gimple_simplify (gimple *stmt, gimple_match_op
> >> *res_op, gimple_seq *seq,
> >> {
> >> tree fn = gimple_call_fn (stmt);
> >> if (!fn)
> >> - return false;
> >> + return -1;
> >>
> >> - 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;
> >> + return -1;
> >>
> >> tree decl = TREE_OPERAND (fn, 0);
> >> if (DECL_BUILT_IN_CLASS (decl) != BUILT_IN_NORMAL
> >> || !gimple_builtin_call_types_compatible_p (stmt, decl))
> >> - return false;
> >> + return -1;
> >>
> >> cfn = as_combined_fn (DECL_FUNCTION_CODE (decl));
> >> }
> >> @@ -1044,56 +1013,122 @@ 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 -2;
> >> }
> >> 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 2;
> >> }
> >>
> >> default:
> >> break;
> >> }
> >>
> >> - return false;
> >> + return -1;
> >> }
> >>
> >> +/* 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, nop) != -1;
> >> +}
> >> +
> >> +/* 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);
> >> + };
> >> + auto valueize_name = [&](tree op)
> >> + {
> >> + return top_valueize ? top_valueize (op) : op;
> >> + };
> >> +
> >> + int res = gimple_extract (stmt, res_op, valueize_op, valueize_condition,
> >> + valueize_name);
> >> + if (res == -1)
> >> + return false;
> >> +
> >> + if (res == -2)
> >> + {
> >> + combined_fn cfn = combined_fn (res_op->code);
> >> + if (internal_fn_p (cfn)
> >> + && try_conditional_simplification (as_internal_fn (cfn),
> >> + res_op, seq, valueize))
> >> + return true;
> >> + res = res_op->num_ops;
> >> + }
> >> +
> >> + switch (res)
> >> + {
> >> + case 0:
> >> + return valueized;
> >> + 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);
> >
> > can't you use just res.resimplify (seq, valueize) || valueized instead of
> > the
> > switch here when res is not zero?
> >
> > Otherwise looks OK.
> >
> > Thanks,
> > Richard.
> >
> >> + default:
> >> + gcc_unreachable ();
> >> + }
> >> +}
> >>
> >> /* Helper for the autogenerated code, valueize OP. */
> >>
> >> diff --git a/gcc/gimple-match.h b/gcc/gimple-match.h
> >> index 2d4ea476076..15a0f584db7 100644
> >> --- a/gcc/gimple-match.h
> >> +++ b/gcc/gimple-match.h
> >> @@ -333,6 +333,7 @@ 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
> >>
