Hello world,
this fixes PR 71902. The recent fix for PR 71783 introduced a
performance and code size regression a string temporary was created for
the test case when it was not actually needed.
I also took the opportunity of renaming the misnomed temporary
variable.
Regression-tested.
OK for trunk?
Do we actually want to backport this? Technically, it is a regression,
but people are not likely to notice much.
Regards
Thomas
2016-07-16 Thomas Koenig <tkoe...@gcc.gnu.org>
PR fortran/71902
* dependency.c (gfc_check_dependency): Use dep_ref. Handle case
if identical is true and two array element references differ.
(gfc_dep_resovler): Move most of the code to dep_ref.
(dep_ref): New function.
* frontend-passes.c (realloc_string_callback): Name temporary
variable "realloc_string".
2016-07-16 Thomas Koenig <tkoe...@gcc.gnu.org>
PR fortran/71902
* gfortran.dg/dependency_47.f90: New test.
Index: dependency.c
===================================================================
--- dependency.c (Revision 238223)
+++ dependency.c (Arbeitskopie)
@@ -54,6 +54,8 @@ enum gfc_dependency
static gfc_dependency check_section_vs_section (gfc_array_ref *,
gfc_array_ref *, int);
+static gfc_dependency dep_ref (gfc_ref *, gfc_ref *, gfc_reverse *);
+
/* Returns 1 if the expr is an integer constant value 1, 0 if it is not or
def if the value could not be determined. */
@@ -1316,14 +1318,34 @@ gfc_check_dependency (gfc_expr *expr1, gfc_expr *e
return 0;
}
- if (identical)
- return 1;
-
/* Identical and disjoint ranges return 0,
overlapping ranges return 1. */
if (expr1->ref && expr2->ref)
- return gfc_dep_resolver (expr1->ref, expr2->ref, NULL);
+ {
+ gfc_dependency dep;
+ dep = dep_ref (expr1->ref, expr2->ref, NULL);
+ switch (dep)
+ {
+ case GFC_DEP_EQUAL:
+ return identical;
+ case GFC_DEP_FORWARD:
+ return 0;
+
+ case GFC_DEP_BACKWARD:
+ return 1;
+
+ case GFC_DEP_OVERLAP:
+ return 1;
+
+ case GFC_DEP_NODEP:
+ return 0;
+
+ case GFC_DEP_ERROR:
+ return 0;
+ }
+ }
+
return 1;
case EXPR_FUNCTION:
@@ -2052,11 +2074,44 @@ ref_same_as_full_array (gfc_ref *full_ref, gfc_ref
2 : array references are overlapping but reversal of one or
more dimensions will clear the dependency.
1 : array references are overlapping.
- 0 : array references are identical or not overlapping. */
+ 0 : array references are identical or can be handled in a forward loop. */
int
gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse)
{
+ enum gfc_dependency dep;
+ dep = dep_ref (lref, rref, reverse);
+ switch (dep)
+ {
+ case GFC_DEP_EQUAL:
+ return 0;
+
+ case GFC_DEP_FORWARD:
+ return 0;
+
+ case GFC_DEP_BACKWARD:
+ return 2;
+
+ case GFC_DEP_OVERLAP:
+ return 1;
+
+ case GFC_DEP_NODEP:
+ return 0;
+
+ case GFC_DEP_ERROR:
+ return 0;
+
+ default:
+ gcc_unreachable();
+ }
+}
+
+/* Compare two references, returning an enum gfc_dependency depending on the
+ "worst" type of dependency found. */
+
+static gfc_dependency
+dep_ref (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse)
+{
int n;
int m;
gfc_dependency fin_dep;
@@ -2079,21 +2134,21 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gf
/* The two ranges can't overlap if they are from different
components. */
if (lref->u.c.component != rref->u.c.component)
- return 0;
+ return GFC_DEP_NODEP;
break;
case REF_SUBSTRING:
/* Substring overlaps are handled by the string assignment code
if there is not an underlying dependency. */
- return (fin_dep == GFC_DEP_OVERLAP) ? 1 : 0;
+ return fin_dep;
case REF_ARRAY:
if (ref_same_as_full_array (lref, rref))
- return 0;
+ return GFC_DEP_EQUAL;
if (ref_same_as_full_array (rref, lref))
- return 0;
+ return GFC_DEP_EQUAL;
if (lref->u.ar.dimen != rref->u.ar.dimen)
{
@@ -2104,7 +2159,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gf
fin_dep = gfc_full_array_ref_p (lref, NULL) ? GFC_DEP_EQUAL
: GFC_DEP_OVERLAP;
else
- return 1;
+ return GFC_DEP_OVERLAP;
break;
}
@@ -2148,7 +2203,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gf
/* If any dimension doesn't overlap, we have no dependency. */
if (this_dep == GFC_DEP_NODEP)
- return 0;
+ return GFC_DEP_NODEP;
/* Now deal with the loop reversal logic: This only works on
ranges and is activated by setting
@@ -2215,7 +2270,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gf
/* Exactly matching and forward overlapping ranges don't cause a
dependency. */
if (fin_dep < GFC_DEP_BACKWARD)
- return 0;
+ return fin_dep;
/* Keep checking. We only have a dependency if
subsequent references also overlap. */
@@ -2233,7 +2288,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gf
/* Assume the worst if we nest to different depths. */
if (lref || rref)
- return 1;
+ return GFC_DEP_OVERLAP;
- return fin_dep == GFC_DEP_OVERLAP;
+ return fin_dep;
}
Index: frontend-passes.c
===================================================================
--- frontend-passes.c (Revision 238223)
+++ frontend-passes.c (Arbeitskopie)
@@ -185,7 +185,7 @@ realloc_string_callback (gfc_code **c, int *walk_s
current_code = c;
inserted_block = NULL;
changed_statement = NULL;
- n = create_var (expr2, "trim");
+ n = create_var (expr2, "realloc_string");
co->expr2 = n;
return 0;
}
! { dg-do compile }
! Make sure there is only one instance of a temporary variable here.
! { dg-options "-fdump-tree-original" }
SUBROUTINE prtdata(ilen)
INTEGER :: ilen
character(len=ilen), allocatable :: cline(:)
allocate(cline(2))
cline(1) = 'a'
cline(1)(2:3) = cline(1)(1:2)
cline(2) = cline(1)
print *,c
END SUBROUTINE prtdata
! { dg-final { scan-tree-dump-not "__var_2" "original" } }
! { dg-final { scan-tree-dump-times "__var_1" 3 "original" } }
