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trans-stmt.c (compute_overall_iter_number): Document function arguments.

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* trans-stmt.c (compute_overall_iter_number): Document function
	arguments.  Generalize "unconditional forall nest with constant
	bounds" optimization to eliminate unconditional inner loops with
	constant bounds.

From-SVN: r121489
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Roger Sayle 2007-02-02 03:49:36 +00:00 committed by Roger Sayle
parent 546dcc4352
commit 2ad62c9b34
2 changed files with 32 additions and 28 deletions
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7
gcc/fortran/ChangeLog
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@ -1,3 +1,10 @@
2007-02-01 Roger Sayle <roger@eyesopen.com>
* trans-stmt.c (compute_overall_iter_number): Document function
arguments. Generalize "unconditional forall nest with constant
bounds" optimization to eliminate unconditional inner loops with
constant bounds.
2007-01-31 Tobias Burnus <burnus@net-b.de>
PR fortran/30520

53
gcc/fortran/trans-stmt.c
View File

@ -2022,51 +2022,48 @@ compute_inner_temp_size (gfc_expr *expr1, gfc_expr *expr2,
}
/* Calculate the overall iterator number of the nested forall construct. */
/* Calculate the overall iterator number of the nested forall construct.
This routine actually calculates the number of times the body of the
nested forall specified by NESTED_FORALL_INFO is executed and multiplies
that by the expression INNER_SIZE. The BLOCK argument specifies the
block in which to calculate the result, and the optional INNER_SIZE_BODY
argument contains any statements that need to executed (inside the loop)
to initialize or calculate INNER_SIZE. */
static tree
compute_overall_iter_number (forall_info *nested_forall_info, tree inner_size,
stmtblock_t *inner_size_body, stmtblock_t *block)
{
forall_info *forall_tmp = nested_forall_info;
tree tmp, number;
stmtblock_t body;
/* Optimize the case of unconditional FORALL nests with constant bounds. */
/* We can eliminate the innermost unconditional loops with constant
array bounds. */
if (INTEGER_CST_P (inner_size))
{
bool all_const_p = true;
forall_info *forall_tmp;
/* First check whether all the bounds are constant. */
for (forall_tmp = nested_forall_info;
forall_tmp;
forall_tmp = forall_tmp->prev_nest)
if (forall_tmp->mask || !INTEGER_CST_P (forall_tmp->size))
{
all_const_p = false;
break;
}
if (all_const_p)
while (forall_tmp
&& !forall_tmp->mask
&& INTEGER_CST_P (forall_tmp->size))
{
tree tmp = inner_size;
for (forall_tmp = nested_forall_info;
forall_tmp;
forall_tmp = forall_tmp->prev_nest)
tmp = fold_build2 (MULT_EXPR, gfc_array_index_type,
tmp, forall_tmp->size);
return tmp;
inner_size = fold_build2 (MULT_EXPR, gfc_array_index_type,
inner_size, forall_tmp->size);
forall_tmp = forall_tmp->prev_nest;
}
/* If there are no loops left, we have our constant result. */
if (!forall_tmp)
return inner_size;
}
/* TODO: optimizing the computing process. */
/* Otherwise, create a temporary variable to compute the result. */
number = gfc_create_var (gfc_array_index_type, "num");
gfc_add_modify_expr (block, number, gfc_index_zero_node);
gfc_start_block (&body);
if (inner_size_body)
gfc_add_block_to_block (&body, inner_size_body);
if (nested_forall_info)
if (forall_tmp)
tmp = build2 (PLUS_EXPR, gfc_array_index_type, number,
inner_size);
else
@ -2075,8 +2072,8 @@ compute_overall_iter_number (forall_info *nested_forall_info, tree inner_size,
tmp = gfc_finish_block (&body);
/* Generate loops. */
if (nested_forall_info != NULL)
tmp = gfc_trans_nested_forall_loop (nested_forall_info, tmp, 1);
if (forall_tmp != NULL)
tmp = gfc_trans_nested_forall_loop (forall_tmp, tmp, 1);
gfc_add_expr_to_block (block, tmp);