https://gcc.gnu.org/g:a763ce804b646565d1911914e32a18cfb6c975c6
commit a763ce804b646565d1911914e32a18cfb6c975c6
Author: Mikael Morin <mik...@gcc.gnu.org>
Date: Fri Feb 14 13:50:51 2025 +0100
fortran: Evaluate class function bounds in the scalarizer
This one may look like a collection of obscure random changes.
It started with the removal of an isolated array descriptor offset
update, and the chain of regression fixes that followed completed it to
the below. I have even found a testcase that is fixed by it.
OK for master?
-- >8 --
There is code in gfc_conv_procedure_call that, for polymorphic
functions, initializes the scalarization array descriptor
information and forcedfully sets loop bounds. This code is changing
the decisions made by the scalarizer behind his back, and the test shows
an example where the consequences are (badly) visible. In the test, for
one of the actual arguments to an elemental subroutine, an offset to the
loop variable is missing to access the array, as it was the one
originally chosen to set loop bounds from.
This could theoretically be fixed by just clearing the array of choice
for the loop bounds. This change takes instead the harder path of
adding the missing information to the scalarizer's knowledge so that its
decision doesn't need to be forced to something else after the fact.
The array descriptor information initialisation for polymorphic
functions is moved to gfc_add_loop_ss_code (after the function call
generation), and the loop bounds initialization to a new function called
after that.
As the array chosen to set the loop bounds from is no longer forced
to be the polymorphic function result, we have to let the scalarizer set
a delta for polymorphic function results. For regular non-polymorphic
function result arrays, they are zero-based and the temporary creation
makes the loop zero-based as well, so we can continue to skip the delta
calculation.
In the cases where a temporary is created to store the result of the
array function, the creation of the temporary shifts the loop bounds
to be zero-based. As there was no delta for polymorphic result arrays,
the function result descriptor offset was set to zero in that case for
a zero-based array reference to be correct. Now that the scalarizer
sets a delta, those forced offset updates have to go because they can
make the descriptor invalid and cause erroneous array references.
gcc/fortran/ChangeLog:
* trans-expr.cc (gfc_conv_subref_array_arg): Remove offset
update.
(gfc_conv_procedure_call): For polymorphic functions, move the
scalarizer descriptor information...
* trans-array.cc (gfc_add_loop_ss_code): ... here, and evaluate
the bounds to fresh variables.
(get_class_info_from_ss): Remove offset update.
(gfc_conv_ss_startstride): Don't set a zero value for function
result upper bounds.
(late_set_loop_bounds): New.
(gfc_conv_loop_setup): If the bounds of a function result have
been set, and no other array provided loop bounds for a
dimension, use the function result bounds as loop bounds for
that dimension.
(gfc_set_delta): Don't skip delta setting for polymorphic
function results.
Diff:
---
gcc/fortran/trans-array.cc | 113 ++++++++++++++++++++++++++++++++++++---------
gcc/fortran/trans-expr.cc | 35 ++------------
2 files changed, 94 insertions(+), 54 deletions(-)
diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc
index 0f7637dd535c..9a738bd5204d 100644
--- a/gcc/fortran/trans-array.cc
+++ b/gcc/fortran/trans-array.cc
@@ -1426,12 +1426,6 @@ get_class_info_from_ss (stmtblock_t * pre, gfc_ss *ss,
tree *eltype,
tmp2 = gfc_class_len_get (class_expr);
gfc_add_modify (pre, tmp, tmp2);
}
-
- if (rhs_function)
- {
- tmp = gfc_class_data_get (class_expr);
- gfc_conv_descriptor_offset_set (pre, tmp, gfc_index_zero_node);
- }
}
else if (rhs_ss->info->data.array.descriptor)
{
@@ -3372,18 +3366,48 @@ gfc_add_loop_ss_code (gfc_loopinfo * loop, gfc_ss * ss,
bool subscript,
break;
case GFC_SS_FUNCTION:
- /* Array function return value. We call the function and save its
- result in a temporary for use inside the loop. */
- gfc_init_se (&se, NULL);
- se.loop = loop;
- se.ss = ss;
- if (gfc_is_class_array_function (expr))
- expr->must_finalize = 1;
- gfc_conv_expr (&se, expr);
- gfc_add_block_to_block (&outer_loop->pre, &se.pre);
- gfc_add_block_to_block (&outer_loop->post, &se.post);
- gfc_add_block_to_block (&outer_loop->post, &se.finalblock);
- ss_info->string_length = se.string_length;
+ {
+ /* Array function return value. We call the function and save its
+ result in a temporary for use inside the loop. */
+ gfc_init_se (&se, NULL);
+ se.loop = loop;
+ se.ss = ss;
+ bool class_func = gfc_is_class_array_function (expr);
+ if (class_func)
+ expr->must_finalize = 1;
+ gfc_conv_expr (&se, expr);
+ gfc_add_block_to_block (&outer_loop->pre, &se.pre);
+ if (class_func
+ && se.expr
+ && GFC_CLASS_TYPE_P (TREE_TYPE (se.expr)))
+ {
+ tree tmp = gfc_class_data_get (se.expr);
+ info->descriptor = tmp;
+ info->data = gfc_conv_descriptor_data_get (tmp);
+ info->offset = gfc_conv_descriptor_offset_get (tmp);
+ for (gfc_ss *s = ss; s; s = s->parent)
+ for (int n = 0; n < s->dimen; n++)
+ {
+ int dim = s->dim[n];
+ tree tree_dim = gfc_rank_cst[dim];
+
+ tree start = gfc_conv_descriptor_lbound_get (tmp,
tree_dim);
+ start = gfc_evaluate_now (start, &outer_loop->pre);
+ info->start[dim] = start;
+
+ tree end = gfc_conv_descriptor_ubound_get (tmp, tree_dim);
+ end = gfc_evaluate_now (end, &outer_loop->pre);
+ info->end[dim] = end;
+
+ tree stride = gfc_conv_descriptor_stride_get (tmp,
tree_dim);
+ stride = gfc_evaluate_now (stride, &outer_loop->pre);
+ info->stride[dim] = stride;
+ }
+ }
+ gfc_add_block_to_block (&outer_loop->post, &se.post);
+ gfc_add_block_to_block (&outer_loop->post, &se.finalblock);
+ ss_info->string_length = se.string_length;
+ }
break;
case GFC_SS_CONSTRUCTOR:
@@ -5383,7 +5407,8 @@ done:
int dim = ss->dim[n];
info->start[dim] = gfc_index_zero_node;
- info->end[dim] = gfc_index_zero_node;
+ if (ss_info->type != GFC_SS_FUNCTION)
+ info->end[dim] = gfc_index_zero_node;
info->stride[dim] = gfc_index_one_node;
}
break;
@@ -6068,6 +6093,46 @@ set_loop_bounds (gfc_loopinfo *loop)
}
+/* Last attempt to set the loop bounds, in case they depend on an allocatable
+ function result. */
+
+static void
+late_set_loop_bounds (gfc_loopinfo *loop)
+{
+ int n, dim;
+ gfc_array_info *info;
+ gfc_ss **loopspec;
+
+ loopspec = loop->specloop;
+
+ for (n = 0; n < loop->dimen; n++)
+ {
+ /* Set the extents of this range. */
+ if (loop->from[n] == NULL_TREE
+ || loop->to[n] == NULL_TREE)
+ {
+ /* We should have found the scalarization loop specifier. If not,
+ that's bad news. */
+ gcc_assert (loopspec[n]);
+
+ info = &loopspec[n]->info->data.array;
+ dim = loopspec[n]->dim[n];
+
+ if (loopspec[n]->info->type == GFC_SS_FUNCTION
+ && info->start[dim]
+ && info->end[dim])
+ {
+ loop->from[n] = info->start[dim];
+ loop->to[n] = info->end[dim];
+ }
+ }
+ }
+
+ for (loop = loop->nested; loop; loop = loop->next)
+ late_set_loop_bounds (loop);
+}
+
+
/* Initialize the scalarization loop. Creates the loop variables. Determines
the range of the loop variables. Creates a temporary if required.
Also generates code for scalar expressions which have been
@@ -6086,6 +6151,8 @@ gfc_conv_loop_setup (gfc_loopinfo * loop, locus * where)
allocating the temporary. */
gfc_add_loop_ss_code (loop, loop->ss, false, where);
+ late_set_loop_bounds (loop);
+
tmp_ss = loop->temp_ss;
/* If we want a temporary then create it. */
if (tmp_ss != NULL)
@@ -6142,9 +6209,11 @@ gfc_set_delta (gfc_loopinfo *loop)
gfc_ss_type ss_type;
ss_type = ss->info->type;
- if (ss_type != GFC_SS_SECTION
- && ss_type != GFC_SS_COMPONENT
- && ss_type != GFC_SS_CONSTRUCTOR)
+ if (!(ss_type == GFC_SS_SECTION
+ || ss_type == GFC_SS_COMPONENT
+ || ss_type == GFC_SS_CONSTRUCTOR
+ || (ss_type == GFC_SS_FUNCTION
+ && gfc_is_class_array_function (ss->info->expr))))
continue;
info = &ss->info->data.array;
diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index 0db7ba3fd52e..bfc38add72d0 100644
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -5485,16 +5485,6 @@ gfc_conv_subref_array_arg (gfc_se *se, gfc_expr * expr,
int g77,
/* Translate the expression. */
gfc_conv_expr (&rse, expr);
- /* Reset the offset for the function call since the loop
- is zero based on the data pointer. Note that the temp
- comes first in the loop chain since it is added second. */
- if (gfc_is_class_array_function (expr))
- {
- tmp = loop.ss->loop_chain->info->data.array.descriptor;
- gfc_conv_descriptor_offset_set (&loop.pre, tmp,
- gfc_index_zero_node);
- }
-
gfc_conv_tmp_array_ref (&lse);
if (intent != INTENT_OUT)
@@ -8864,28 +8854,9 @@ gfc_conv_procedure_call (gfc_se * se, gfc_symbol * sym,
&& se->expr && GFC_CLASS_TYPE_P (TREE_TYPE (se->expr))
&& expr->must_finalize)
{
- int n;
- if (se->ss && se->ss->loop)
- {
- gfc_add_block_to_block (&se->ss->loop->pre, &se->pre);
- se->expr = gfc_evaluate_now (se->expr, &se->ss->loop->pre);
- tmp = gfc_class_data_get (se->expr);
- info->descriptor = tmp;
- info->data = gfc_conv_descriptor_data_get (tmp);
- info->offset = gfc_conv_descriptor_offset_get (tmp);
- for (n = 0; n < se->ss->loop->dimen; n++)
- {
- tree dim = gfc_rank_cst[n];
- se->ss->loop->to[n] = gfc_conv_descriptor_ubound_get (tmp,
dim);
- se->ss->loop->from[n] = gfc_conv_descriptor_lbound_get (tmp,
dim);
- }
- }
- else
- {
- /* TODO Eliminate the doubling of temporaries. This
- one is necessary to ensure no memory leakage. */
- se->expr = gfc_evaluate_now (se->expr, &se->pre);
- }
+ /* TODO Eliminate the doubling of temporaries. This
+ one is necessary to ensure no memory leakage. */
+ se->expr = gfc_evaluate_now (se->expr, &se->pre);
/* Finalize the result, if necessary. */
attr = expr->value.function.esym
