/* Dependency analysis
- Copyright (C) 2000, 2001, 2002, 2005, 2006, 2007
+ Copyright (C) 2000, 2001, 2002, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
Contributed by Paul Brook <paul@nowt.org>
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 2, or (at your option) any later
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
/* dependency.c -- Expression dependency analysis code. */
/* There's probably quite a bit of duplication in this file. We currently
{
GFC_DEP_ERROR,
GFC_DEP_EQUAL, /* Identical Ranges. */
- GFC_DEP_FORWARD, /* eg. a(1:3), a(2:4). */
+ GFC_DEP_FORWARD, /* e.g., a(1:3), a(2:4). */
GFC_DEP_OVERLAP, /* May overlap in some other way. */
GFC_DEP_NODEP /* Distinct ranges. */
}
int i;
if (e1->expr_type == EXPR_OP
- && (e1->value.op.operator == INTRINSIC_UPLUS
- || e1->value.op.operator == INTRINSIC_PARENTHESES))
+ && (e1->value.op.op == INTRINSIC_UPLUS
+ || e1->value.op.op == INTRINSIC_PARENTHESES))
return gfc_dep_compare_expr (e1->value.op.op1, e2);
if (e2->expr_type == EXPR_OP
- && (e2->value.op.operator == INTRINSIC_UPLUS
- || e2->value.op.operator == INTRINSIC_PARENTHESES))
+ && (e2->value.op.op == INTRINSIC_UPLUS
+ || e2->value.op.op == INTRINSIC_PARENTHESES))
return gfc_dep_compare_expr (e1, e2->value.op.op1);
- if (e1->expr_type == EXPR_OP && e1->value.op.operator == INTRINSIC_PLUS)
+ if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_PLUS)
{
/* Compare X+C vs. X. */
if (e1->value.op.op2->expr_type == EXPR_CONSTANT
return mpz_sgn (e1->value.op.op2->value.integer);
/* Compare P+Q vs. R+S. */
- if (e2->expr_type == EXPR_OP && e2->value.op.operator == INTRINSIC_PLUS)
+ if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS)
{
int l, r;
}
/* Compare X vs. X+C. */
- if (e2->expr_type == EXPR_OP && e2->value.op.operator == INTRINSIC_PLUS)
+ if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_PLUS)
{
if (e2->value.op.op2->expr_type == EXPR_CONSTANT
&& e2->value.op.op2->ts.type == BT_INTEGER
}
/* Compare X-C vs. X. */
- if (e1->expr_type == EXPR_OP && e1->value.op.operator == INTRINSIC_MINUS)
+ if (e1->expr_type == EXPR_OP && e1->value.op.op == INTRINSIC_MINUS)
{
if (e1->value.op.op2->expr_type == EXPR_CONSTANT
&& e1->value.op.op2->ts.type == BT_INTEGER
return -mpz_sgn (e1->value.op.op2->value.integer);
/* Compare P-Q vs. R-S. */
- if (e2->expr_type == EXPR_OP && e2->value.op.operator == INTRINSIC_MINUS)
+ if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS)
{
int l, r;
}
/* Compare X vs. X-C. */
- if (e2->expr_type == EXPR_OP && e2->value.op.operator == INTRINSIC_MINUS)
+ if (e2->expr_type == EXPR_OP && e2->value.op.op == INTRINSIC_MINUS)
{
if (e2->value.op.op2->expr_type == EXPR_CONSTANT
&& e2->value.op.op2->ts.type == BT_INTEGER
case EXPR_OP:
/* Intrinsic operators are the same if their operands are the same. */
- if (e1->value.op.operator != e2->value.op.operator)
+ if (e1->value.op.op != e2->value.op.op)
return -2;
if (e1->value.op.op2 == 0)
{
/* We should list the "constant" intrinsic functions. Those
without side-effects that provide equal results given equal
argument lists. */
- switch (e1->value.function.isym->generic_id)
+ switch (e1->value.function.isym->id)
{
case GFC_ISYM_CONVERSION:
/* Handle integer extensions specially, as __convert_i4_i8
if (expr->expr_type != EXPR_FUNCTION || !expr->value.function.isym)
return NULL;
- switch (expr->value.function.isym->generic_id)
+ switch (expr->value.function.isym->id)
{
case GFC_ISYM_TRANSPOSE:
return expr->value.function.actual->expr;
}
+int
+gfc_is_data_pointer (gfc_expr *e)
+{
+ gfc_ref *ref;
+
+ if (e->expr_type != EXPR_VARIABLE && e->expr_type != EXPR_FUNCTION)
+ return 0;
+
+ /* No subreference if it is a function */
+ gcc_assert (e->expr_type == EXPR_VARIABLE || !e->ref);
+
+ if (e->symtree->n.sym->attr.pointer)
+ return 1;
+
+ for (ref = e->ref; ref; ref = ref->next)
+ if (ref->type == REF_COMPONENT && ref->u.c.component->attr.pointer)
+ return 1;
+
+ return 0;
+}
+
+
/* Return true if array variable VAR could be passed to the same function
as argument EXPR without interfering with EXPR. INTENT is the intent
of VAR.
static int
gfc_check_argument_var_dependency (gfc_expr *var, sym_intent intent,
- gfc_expr *expr)
+ gfc_expr *expr, gfc_dep_check elemental)
{
+ gfc_expr *arg;
+
gcc_assert (var->expr_type == EXPR_VARIABLE);
gcc_assert (var->rank > 0);
switch (expr->expr_type)
{
case EXPR_VARIABLE:
- return (gfc_ref_needs_temporary_p (expr->ref)
- || gfc_check_dependency (var, expr, 1));
+ /* In case of elemental subroutines, there is no dependency
+ between two same-range array references. */
+ if (gfc_ref_needs_temporary_p (expr->ref)
+ || gfc_check_dependency (var, expr, !elemental))
+ {
+ if (elemental == ELEM_DONT_CHECK_VARIABLE)
+ {
+ /* Too many false positive with pointers. */
+ if (!gfc_is_data_pointer (var) && !gfc_is_data_pointer (expr))
+ {
+ /* Elemental procedures forbid unspecified intents,
+ and we don't check dependencies for INTENT_IN args. */
+ gcc_assert (intent == INTENT_OUT || intent == INTENT_INOUT);
+
+ /* We are told not to check dependencies.
+ We do it, however, and issue a warning in case we find one.
+ If a dependency is found in the case
+ elemental == ELEM_CHECK_VARIABLE, we will generate
+ a temporary, so we don't need to bother the user. */
+ gfc_warning ("INTENT(%s) actual argument at %L might "
+ "interfere with actual argument at %L.",
+ intent == INTENT_OUT ? "OUT" : "INOUT",
+ &var->where, &expr->where);
+ }
+ return 0;
+ }
+ else
+ return 1;
+ }
+ return 0;
case EXPR_ARRAY:
return gfc_check_dependency (var, expr, 1);
case EXPR_FUNCTION:
- if (intent != INTENT_IN && expr->inline_noncopying_intrinsic)
+ if (intent != INTENT_IN && expr->inline_noncopying_intrinsic
+ && (arg = gfc_get_noncopying_intrinsic_argument (expr))
+ && gfc_check_argument_var_dependency (var, intent, arg, elemental))
+ return 1;
+ if (elemental)
+ {
+ if ((expr->value.function.esym
+ && expr->value.function.esym->attr.elemental)
+ || (expr->value.function.isym
+ && expr->value.function.isym->elemental))
+ return gfc_check_fncall_dependency (var, intent, NULL,
+ expr->value.function.actual,
+ ELEM_CHECK_VARIABLE);
+ }
+ return 0;
+
+ case EXPR_OP:
+ /* In case of non-elemental procedures, there is no need to catch
+ dependencies, as we will make a temporary anyway. */
+ if (elemental)
{
- expr = gfc_get_noncopying_intrinsic_argument (expr);
- return gfc_check_argument_var_dependency (var, intent, expr);
+ /* If the actual arg EXPR is an expression, we need to catch
+ a dependency between variables in EXPR and VAR,
+ an intent((IN)OUT) variable. */
+ if (expr->value.op.op1
+ && gfc_check_argument_var_dependency (var, intent,
+ expr->value.op.op1,
+ ELEM_CHECK_VARIABLE))
+ return 1;
+ else if (expr->value.op.op2
+ && gfc_check_argument_var_dependency (var, intent,
+ expr->value.op.op2,
+ ELEM_CHECK_VARIABLE))
+ return 1;
}
return 0;
static int
gfc_check_argument_dependency (gfc_expr *other, sym_intent intent,
- gfc_expr *expr)
+ gfc_expr *expr, gfc_dep_check elemental)
{
switch (other->expr_type)
{
case EXPR_VARIABLE:
- return gfc_check_argument_var_dependency (other, intent, expr);
+ return gfc_check_argument_var_dependency (other, intent, expr, elemental);
case EXPR_FUNCTION:
if (other->inline_noncopying_intrinsic)
{
other = gfc_get_noncopying_intrinsic_argument (other);
- return gfc_check_argument_dependency (other, INTENT_IN, expr);
+ return gfc_check_argument_dependency (other, INTENT_IN, expr,
+ elemental);
}
return 0;
int
gfc_check_fncall_dependency (gfc_expr *other, sym_intent intent,
- gfc_symbol *fnsym, gfc_actual_arglist *actual)
+ gfc_symbol *fnsym, gfc_actual_arglist *actual,
+ gfc_dep_check elemental)
{
gfc_formal_arglist *formal;
gfc_expr *expr;
&& formal->sym->attr.intent == INTENT_IN)
continue;
- if (gfc_check_argument_dependency (other, intent, expr))
+ if (gfc_check_argument_dependency (other, intent, expr, elemental))
return 1;
}
/* Return 1 if e1 and e2 are equivalenced arrays, either
- directly or indirectly; ie. equivalence (a,b) for a and b
+ directly or indirectly; i.e., equivalence (a,b) for a and b
or equivalence (a,c),(b,c). This function uses the equiv_
lists, generated in trans-common(add_equivalences), that are
guaranteed to pick up indirect equivalences. We explicitly
|| !e2->symtree->n.sym->attr.in_equivalence|| !e1->rank || !e2->rank)
return 0;
+ if (e1->symtree->n.sym->ns
+ && e1->symtree->n.sym->ns != gfc_current_ns)
+ l = e1->symtree->n.sym->ns->equiv_lists;
+ else
+ l = gfc_current_ns->equiv_lists;
+
/* Go through the equiv_lists and return 1 if the variables
e1 and e2 are members of the same group and satisfy the
requirement on their relative offsets. */
- for (l = gfc_current_ns->equiv_lists; l; l = l->next)
+ for (; l; l = l->next)
{
fl1 = NULL;
fl2 = NULL;
int
gfc_check_dependency (gfc_expr *expr1, gfc_expr *expr2, bool identical)
{
- gfc_ref *ref;
- int n;
gfc_actual_arglist *actual;
+ gfc_constructor *c;
+ int n;
gcc_assert (expr1->expr_type == EXPR_VARIABLE);
/* If either variable is a pointer, assume the worst. */
/* TODO: -fassume-no-pointer-aliasing */
- if (expr1->symtree->n.sym->attr.pointer)
- return 1;
- for (ref = expr1->ref; ref; ref = ref->next)
- if (ref->type == REF_COMPONENT && ref->u.c.component->pointer)
- return 1;
-
- if (expr2->symtree->n.sym->attr.pointer)
+ if (gfc_is_data_pointer (expr1) || gfc_is_data_pointer (expr2))
return 1;
- for (ref = expr2->ref; ref; ref = ref->next)
- if (ref->type == REF_COMPONENT && ref->u.c.component->pointer)
- return 1;
/* Otherwise distinct symbols have no dependencies. */
return 0;
/* Identical and disjoint ranges return 0,
overlapping ranges return 1. */
- /* Return zero if we refer to the same full arrays. */
- if (expr1->ref->type == REF_ARRAY && expr2->ref->type == REF_ARRAY)
+ if (expr1->ref && expr2->ref)
return gfc_dep_resolver (expr1->ref, expr2->ref);
return 1;
return 0;
case EXPR_ARRAY:
- /* Probably ok in the majority of (constant) cases. */
- return 1;
+ /* Loop through the array constructor's elements. */
+ for (c = expr2->value.constructor; c; c = c->next)
+ {
+ /* If this is an iterator, assume the worst. */
+ if (c->iterator)
+ return 1;
+ /* Avoid recursion in the common case. */
+ if (c->expr->expr_type == EXPR_CONSTANT)
+ continue;
+ if (gfc_check_dependency (expr1, c->expr, 1))
+ return 1;
+ }
+ return 0;
default:
return 1;
for (i = 0; i < ref->u.ar.dimen; i++)
{
+ /* If we have a single element in the reference, we need to check
+ that the array has a single element and that we actually reference
+ the correct element. */
+ if (ref->u.ar.dimen_type[i] == DIMEN_ELEMENT)
+ {
+ if (!ref->u.ar.as
+ || !ref->u.ar.as->lower[i]
+ || !ref->u.ar.as->upper[i]
+ || gfc_dep_compare_expr (ref->u.ar.as->lower[i],
+ ref->u.ar.as->upper[i])
+ || !ref->u.ar.start[i]
+ || gfc_dep_compare_expr (ref->u.ar.start[i],
+ ref->u.ar.as->lower[i]))
+ return false;
+ else
+ continue;
+ }
+
/* Check the lower bound. */
if (ref->u.ar.start[i]
&& (!ref->u.ar.as
while (lref && rref)
{
/* We're resolving from the same base symbol, so both refs should be
- the same type. We traverse the reference chain intil we find ranges
+ the same type. We traverse the reference chain until we find ranges
that are not equal. */
gcc_assert (lref->type == rref->type);
switch (lref->type)
break;
case REF_SUBSTRING:
- /* Substring overlaps are handled by the string assignment code. */
- return 0;
+ /* Substring overlaps are handled by the string assignment code
+ if there is not an underlying dependency. */
+ return (fin_dep == GFC_DEP_OVERLAP) ? 1 : 0;
case REF_ARRAY:
if (lref->u.ar.dimen != rref->u.ar.dimen)
if (this_dep > fin_dep)
fin_dep = this_dep;
}
+
+ /* If this is an equal element, we have to keep going until we find
+ the "real" array reference. */
+ if (lref->u.ar.type == AR_ELEMENT
+ && rref->u.ar.type == AR_ELEMENT
+ && fin_dep == GFC_DEP_EQUAL)
+ break;
+
/* Exactly matching and forward overlapping ranges don't cause a
dependency. */
if (fin_dep < GFC_DEP_OVERLAP)
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