dependency.c (gfc_check_dependency): Call gfc_dep_resolver to check whether two array references have a dependency.

	* dependency.c (gfc_check_dependency): Call gfc_dep_resolver to
	check whether two array references have a dependency.
	(gfc_check_element_vs_element): Assume lref and rref must be
	REF_ARRAYs.  If gfc_dep_compare_expr returns -2, assume these
	references could potentially overlap.
	(gfc_dep_resolver): Whitespace and comment tweaks.  Assume a
	dependency if the references have different depths.  Rewrite
	final term to clarrify we only have a dependency for overlaps.

	* gfortran.dg/dependency_4.f90: New test case.
	* gfortran.dg/dependency_5.f90: New test case.
	* gfortran.dg/dependency_6.f90: New test case.
	* gfortran.dg/dependency_7.f90: New test case.
	* gfortran.dg/dependency_8.f90: New test case.

From-SVN: r111686

8 files changed, 97 insertions, 31 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 81f27ec..07350f4 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,14 @@
+2006-03-03  Roger Sayle  <roger@eyesopen.com>
+
+	* dependency.c (gfc_check_dependency): Call gfc_dep_resolver to
+	check whether two array references have a dependency.
+	(gfc_check_element_vs_element): Assume lref and rref must be
+	REF_ARRAYs.  If gfc_dep_compare_expr returns -2, assume these
+	references could potentially overlap.
+	(gfc_dep_resolver): Whitespace and comment tweaks.  Assume a
+	dependency if the references have different depths.  Rewrite
+	final term to clarrify we only have a dependency for overlaps.
+
 2006-03-03  Thomas Koenig  <Thomas.Koenig@online.de>
 
 	PR fortran/25031
@@ -28,7 +39,7 @@
 	(gfc_trans_where_assign): Likewise.
 	(gfc_trans_where_2): Likewise.  Restructure code that decides
 	whether we need to allocate zero, one or two temporary masks.
-	If this is a top-level WHERE (i.e. the incoming MAKS is NULL),
+	If this is a top-level WHERE (i.e. the incoming MASK is NULL),
 	we only need to allocate at most one temporary mask, and can
 	invert it's sense to provide the complementary pending execution
 	mask.  Only calculate the size of the required temporary arrays
diff --git a/gcc/fortran/dependency.c b/gcc/fortran/dependency.c
index f764873..187b207 100644
--- a/gcc/fortran/dependency.c
+++ b/gcc/fortran/dependency.c
@@ -460,16 +460,11 @@ gfc_check_dependency (gfc_expr * expr1, gfc_expr * expr2, bool identical)
       if (identical)
 	return 1;
 
-      /* Identical ranges return 0, overlapping ranges return 1.  */
-
+      /* Identical and disjoint ranges return 0,
+	 overlapping ranges return 1.  */
       /* Return zero if we refer to the same full arrays.  */
-      if (expr1->ref->type == REF_ARRAY
-	  && expr2->ref->type == REF_ARRAY
-	  && expr1->ref->u.ar.type == AR_FULL
-	  && expr2->ref->u.ar.type == AR_FULL
-	  && !expr1->ref->next
-	  && !expr2->ref->next)
-	return 0;
+      if (expr1->ref->type == REF_ARRAY && expr2->ref->type == REF_ARRAY)
+	return gfc_dep_resolver (expr1->ref, expr2->ref);
 
       return 1;
 
@@ -735,30 +730,25 @@ gfc_check_element_vs_element (gfc_ref * lref, gfc_ref * rref, int n)
   gfc_array_ref r_ar;
   gfc_expr *l_start;
   gfc_expr *r_start;
-  gfc_dependency nIsDep;
-
-  if (lref->type == REF_ARRAY && rref->type == REF_ARRAY)
-    {
-      l_ar = lref->u.ar;
-      r_ar = rref->u.ar;
-      l_start = l_ar.start[n] ;
-      r_start = r_ar.start[n] ;
-      if (gfc_dep_compare_expr (r_start, l_start) == 0)
-	nIsDep = GFC_DEP_EQUAL;
-      else
-	nIsDep = GFC_DEP_NODEP;
-  }
-  else
-    nIsDep = GFC_DEP_NODEP;
+  int i;
 
-  return nIsDep;
+  l_ar = lref->u.ar;
+  r_ar = rref->u.ar;
+  l_start = l_ar.start[n] ;
+  r_start = r_ar.start[n] ;
+  i = gfc_dep_compare_expr (r_start, l_start);
+  if (i == 0)
+    return GFC_DEP_EQUAL;
+  if (i == -2)
+    return GFC_DEP_OVERLAP;
+  return GFC_DEP_NODEP;
 }
 
 
 /* Finds if two array references are overlapping or not.
    Return value
    	1 : array references are overlapping.
-   	0 : array references are not overlapping.  */
+   	0 : array references are identical or not overlapping.  */
 
 int
 gfc_dep_resolver (gfc_ref * lref, gfc_ref * rref)
@@ -792,7 +782,6 @@ gfc_dep_resolver (gfc_ref * lref, gfc_ref * rref)
 	  return 0;
 	
 	case REF_ARRAY:
-	  
 	  for (n=0; n < lref->u.ar.dimen; n++)
 	    {
 	      /* Assume dependency when either of array reference is vector
@@ -844,9 +833,10 @@ gfc_dep_resolver (gfc_ref * lref, gfc_ref * rref)
   /* If we haven't seen any array refs then something went wrong.  */
   gcc_assert (fin_dep != GFC_DEP_ERROR);
 
-  if (fin_dep < GFC_DEP_OVERLAP)
-    return 0;
-  else
+  /* Assume the worst if we nest to different depths.  */
+  if (lref || rref)
     return 1;
+
+  return fin_dep == GFC_DEP_OVERLAP;
 }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f2c1d6a..c56b0f9 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2006-03-03  Roger Sayle  <roger@eyesopen.com>
+
+	* gfortran.dg/dependency_4.f90: New test case.
+	* gfortran.dg/dependency_5.f90: New test case.
+	* gfortran.dg/dependency_6.f90: New test case.
+	* gfortran.dg/dependency_7.f90: New test case.
+	* gfortran.dg/dependency_8.f90: New test case.
+
 2006-03-03  Paul Brook  <paul@codesourcery.com>
 
 	* gcc/testsuite/lib/target-supports.exp (check_profiling_available):
diff --git a/gcc/testsuite/gfortran.dg/dependency_4.f90 b/gcc/testsuite/gfortran.dg/dependency_4.f90
new file mode 100644
index 0000000..9eabaf1
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/dependency_4.f90
@@ -0,0 +1,11 @@
+! { dg-do compile }
+! { dg-options "-O2 -fdump-tree-original" }
+subroutine foo(a)
+  integer, dimension (4) :: a
+
+  where (a .ne. 0)
+    a = 1
+  endwhere
+end subroutine
+! { dg-final { scan-tree-dump-times "malloc" 0 "original" } }
+! { dg-final { cleanup-tree-dump "original" } }
diff --git a/gcc/testsuite/gfortran.dg/dependency_5.f90 b/gcc/testsuite/gfortran.dg/dependency_5.f90
new file mode 100644
index 0000000..307fbd7
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/dependency_5.f90
@@ -0,0 +1,11 @@
+! { dg-do compile }
+! { dg-options "-O2 -fdump-tree-original" }
+subroutine foo(a)
+  integer, dimension (4) :: a
+
+  where (a(:) .ne. 0)
+    a(:) = 1
+  endwhere
+end subroutine
+! { dg-final { scan-tree-dump-times "malloc" 0 "original" } }
+! { dg-final { cleanup-tree-dump "original" } }
diff --git a/gcc/testsuite/gfortran.dg/dependency_6.f90 b/gcc/testsuite/gfortran.dg/dependency_6.f90
new file mode 100644
index 0000000..e90571e
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/dependency_6.f90
@@ -0,0 +1,11 @@
+! { dg-do compile }
+! { dg-options "-O2 -fdump-tree-original" }
+subroutine foo(a)
+  integer, dimension (4) :: a
+
+  where (a(:4) .ne. 0)
+    a(:4) = 1
+  endwhere
+end subroutine
+! { dg-final { scan-tree-dump-times "malloc" 0 "original" } }
+! { dg-final { cleanup-tree-dump "original" } }
diff --git a/gcc/testsuite/gfortran.dg/dependency_7.f90 b/gcc/testsuite/gfortran.dg/dependency_7.f90
new file mode 100644
index 0000000..52bac8f
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/dependency_7.f90
@@ -0,0 +1,11 @@
+! { dg-do compile }
+! { dg-options "-O2 -fdump-tree-original" }
+subroutine foo(a)
+  integer, dimension (4) :: a
+
+  where (a(1:4) .ne. 0)
+    a(1:4) = 1
+  endwhere
+end subroutine
+! { dg-final { scan-tree-dump-times "malloc" 0 "original" } }
+! { dg-final { cleanup-tree-dump "original" } }
diff --git a/gcc/testsuite/gfortran.dg/dependency_8.f90 b/gcc/testsuite/gfortran.dg/dependency_8.f90
new file mode 100644
index 0000000..e27f85a
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/dependency_8.f90
@@ -0,0 +1,13 @@
+! { dg-do compile }
+! { dg-options "-O2 -fdump-tree-original" }
+subroutine foo(a,i,j)
+  integer, dimension (4,4) :: a
+  integer :: i
+  integer :: j
+
+  where (a(i,1:3) .ne. 0)
+    a(j,2:4) = 1
+  endwhere
+end subroutine
+! { dg-final { scan-tree-dump-times "malloc" 1 "original" } }
+! { dg-final { cleanup-tree-dump "original" } }