re PR fortran/43072 (unneeded temporary (s=s+f(a)))

2019-01-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/43072
	* resolve.c (resolve_array_ref): Add equal_length argument; set it
	if the length of the substring equals that of the orignal
	variable.
	(resolve_ref): Remove the substring if it is equal in length to
	the original variable, unless it is an EXPR_SUBSTRING).

2019-01-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/43072
	* gfortran.dg/actual_array_substr_3.f90: New test.

From-SVN: r267953
This commit is contained in:
Thomas Koenig 2019-01-15 22:18:55 +00:00
parent 6a0c8e77f2
commit 0335cc372c
4 changed files with 49 additions and 4 deletions

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@ -1,3 +1,12 @@
2019-01-15 Thomas Koenig <tkoenig@gcc.gnu.org>
PR fortran/43072
* resolve.c (resolve_array_ref): Add equal_length argument; set it
if the length of the substring equals that of the orignal
variable.
(resolve_ref): Remove the substring if it is equal in length to
the original variable, unless it is an EXPR_SUBSTRING).
2019-01-15 Steven G. Kargl <kargl@gcc.gnu.org>
PR fortran/81849

View File

@ -4873,7 +4873,7 @@ resolve_array_ref (gfc_array_ref *ar)
static bool
resolve_substring (gfc_ref *ref)
resolve_substring (gfc_ref *ref, bool *equal_length)
{
int k = gfc_validate_kind (BT_INTEGER, gfc_charlen_int_kind, false);
@ -4944,6 +4944,13 @@ resolve_substring (gfc_ref *ref)
&ref->u.ss.end->where);
return false;
}
/* If the substring has the same length as the original
variable, the reference itself can be deleted. */
if (ref->u.ss.length != NULL
&& compare_bound (ref->u.ss.end, ref->u.ss.length->length) == CMP_EQ
&& compare_bound_int (ref->u.ss.start, 1) == CMP_EQ)
*equal_length = true;
}
return true;
@ -5037,7 +5044,8 @@ static bool
resolve_ref (gfc_expr *expr)
{
int current_part_dimension, n_components, seen_part_dimension;
gfc_ref *ref;
gfc_ref *ref, **prev;
bool equal_length;
for (ref = expr->ref; ref; ref = ref->next)
if (ref->type == REF_ARRAY && ref->u.ar.as == NULL)
@ -5046,7 +5054,8 @@ resolve_ref (gfc_expr *expr)
break;
}
for (ref = expr->ref; ref; ref = ref->next)
for (ref = expr->ref, prev = &expr->ref; ref; prev = &ref->next, ref = ref->next)
switch (ref->type)
{
case REF_ARRAY:
@ -5059,8 +5068,19 @@ resolve_ref (gfc_expr *expr)
break;
case REF_SUBSTRING:
if (!resolve_substring (ref))
equal_length = false;
if (!resolve_substring (ref, &equal_length))
return false;
if (expr->expr_type != EXPR_SUBSTRING && equal_length)
{
/* Remove the reference and move the charlen, if any. */
*prev = ref->next;
ref->next = NULL;
expr->ts.u.cl = ref->u.ss.length;
ref->u.ss.length = NULL;
gfc_free_ref_list (ref);
}
break;
}

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@ -1,3 +1,8 @@
2019-01-15 Thomas Koenig <tkoenig@gcc.gnu.org>
PR fortran/43072
* gfortran.dg/actual_array_substr_3.f90: New test.
2019-01-15 Steven G. Kargl <kargl@gcc.gnu.org>
PR fortran/81849

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@ -0,0 +1,11 @@
! { dg-do compile }
! { dg-additional-options "-fdump-tree-original" }
! PR 43072 - no temporary needed because the substring
! is of equal length to the string.
subroutine foo2
implicit none
external foo
character(len=20) :: str(2) = '1234567890'
call foo(str(:)(1:20))
end
! { dg-final { scan-tree-dump-not "memmove" "original" } }