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re PR fortran/71902 (Unneeded temporary on reallocatable character assignment)

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2016-07-19  Thomas Koenig  <tkoenig@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".

2016-07-19  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/71902
	* gfortran.dg/dependency_47.f90:  New test.

From-SVN: r238497
This commit is contained in:
Thomas Koenig 2016-07-19 21:25:33 +00:00
parent 4833f5615e
commit 6ed825558e
5 changed files with 96 additions and 15 deletions
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10
gcc/fortran/ChangeLog
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@ -1,3 +1,13 @@
2016-07-19 Thomas Koenig <tkoenig@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".
2016-07-17 Fritz Reese <fritzoreese@gmail.com>
PR fortran/71523

79
gcc/fortran/dependency.c
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@ -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. */
@ -1316,13 +1318,33 @@ gfc_check_dependency (gfc_expr *expr1, gfc_expr *expr2, bool identical)
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;
default:
gcc_unreachable();
}
}
return 1;
@ -2052,10 +2074,38 @@ ref_same_as_full_array (gfc_ref *full_ref, gfc_ref *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;
default:
gcc_unreachable();
}
}
static gfc_dependency
dep_ref (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse)
{
int n;
int m;
@ -2079,21 +2129,22 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse)
/* 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 == GFC_DEP_ERROR ? GFC_DEP_NODEP : 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 +2155,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse)
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 +2199,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse)
/* 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 +2266,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse)
/* Exactly matching and forward overlapping ranges don't cause a
dependency. */
if (fin_dep < GFC_DEP_BACKWARD)
return 0;
return fin_dep == GFC_DEP_ERROR ? GFC_DEP_NODEP : fin_dep;
/* Keep checking. We only have a dependency if
subsequent references also overlap. */
@ -2233,7 +2284,7 @@ gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse)
/* 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;
}

2
gcc/fortran/frontend-passes.c
View File

@ -185,7 +185,7 @@ realloc_string_callback (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED,
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;
}

5
gcc/testsuite/ChangeLog
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@ -1,3 +1,8 @@
2016-07-19 Thomas Koenig <tkoenig@gcc.gnu.org>
PR fortran/71902
* gfortran.dg/dependency_47.f90: New test.
2016-07-19 Jakub Jelinek <jakub@redhat.com>
PR rtl-optimization/71916

15
gcc/testsuite/gfortran.dg/dependency_47.f90 Normal file
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@ -0,0 +1,15 @@
! { 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" } }