2017-03-06 Thomas Koenig <tkoenig@gcc.gnu.org>

	PR fortran/84697
	PR fortran/66128
	* expr.c (simplify_parameter_variable): If p is a size zero array
	and not an ARRAY_EXPR insert an empty array constructor and
	return.
	* gfortran.h: Add prototype for gfc_is_size_zero_array.
	* simplify.c (is_size_zero_array): Make non-static and rename into
	(gfc_is_size_zero_array):  Check for parameter arrays of zero
	size by comparing shape and absence of constructor.
	(gfc_simplify_all): Use gfc_is_size_zero_array instead of
	is_size_zero_array.
	(gfc_simplify_count): Likewise.
	(gfc_simplify_iall): Likewise.
	(gfc_simplify_iany): Likewise.
	(gfc_simplify_iparity): Likewise.
	(gfc_simplify_minval): Likewise.
	(gfc_simplify_maxval): Likewise.
	(gfc_simplify_product): Likewise.
	(gfc_simplify_sum): Likewise.

2017-03-06  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/84697
	PR fortran/66128
	* gfortran.dg/minmaxloc_zerosize_1.f90: New test.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@258305 138bc75d-0d04-0410-961f-82ee72b054a4

6 files changed, 101 insertions, 26 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index f5b990d7694..f87cce8c084 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,25 @@
+2017-03-06  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/84697
+	PR fortran/66128
+	* expr.c (simplify_parameter_variable): If p is a size zero array
+	and not an ARRAY_EXPR insert an empty array constructor and
+	return.
+	* gfortran.h: Add prototype for gfc_is_size_zero_array.
+	* simplify.c (is_size_zero_array): Make non-static and rename into
+	(gfc_is_size_zero_array):  Check for parameter arrays of zero
+	size by comparing shape and absence of constructor.
+	(gfc_simplify_all): Use gfc_is_size_zero_array instead of
+	is_size_zero_array.
+	(gfc_simplify_count): Likewise.
+	(gfc_simplify_iall): Likewise.
+	(gfc_simplify_iany): Likewise.
+	(gfc_simplify_iparity): Likewise.
+	(gfc_simplify_minval): Likewise.
+	(gfc_simplify_maxval): Likewise.
+	(gfc_simplify_product): Likewise.
+	(gfc_simplify_sum): Likewise.
+
 2018-03-06  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/56667
diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index 40f20c96ea5..bbaabb684c9 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -1857,6 +1857,22 @@ simplify_parameter_variable (gfc_expr *p, int type)
   gfc_expr *e;
   bool t;
 
+  if (gfc_is_size_zero_array (p))
+    {
+      if (p->expr_type == EXPR_ARRAY)
+	return true;
+
+      e = gfc_get_expr ();
+      e->expr_type = EXPR_ARRAY;
+      e->ts = p->ts;
+      e->rank = p->rank;
+      e->value.constructor = NULL;
+      e->shape = gfc_copy_shape (p->shape, p->rank);
+      e->where = p->where;
+      gfc_replace_expr (p, e);
+      return true;
+    }
+
   e = gfc_copy_expr (p->symtree->n.sym->value);
   if (e == NULL)
     return false;
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 94f7399885a..2bfd1e3019d 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -3464,6 +3464,7 @@ int gfc_code_walker (gfc_code **, walk_code_fn_t, walk_expr_fn_t, void *);
 
 void gfc_convert_mpz_to_signed (mpz_t, int);
 gfc_expr *gfc_simplify_ieee_functions (gfc_expr *);
+bool gfc_is_size_zero_array (gfc_expr *);
 
 /* trans-array.c  */
 
diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index 3bd98688e88..dd469335776 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -259,26 +259,28 @@ is_constant_array_expr (gfc_expr *e)
 }
 
 /* Test for a size zero array.  */
-static bool
-is_size_zero_array (gfc_expr *array)
+bool
+gfc_is_size_zero_array (gfc_expr *array)
 {
-  gfc_expr *e;
-  bool t;
 
-  e = gfc_copy_expr (array);
-  gfc_simplify_expr (e, 1);
+  if (array->rank == 0)
+    return false;
 
-  if (e->expr_type == EXPR_CONSTANT && e->rank > 0 && !e->shape)
-     t = true;
-  else if (e->expr_type == EXPR_ARRAY && e->rank > 0 
-	   && !e->shape && !e->value.constructor)
-     t = true;
-  else
-     t = false;
+  if (array->expr_type == EXPR_VARIABLE && array->rank > 0
+      && array->symtree->n.sym->attr.flavor == FL_PARAMETER
+      && array->shape != NULL)
+    {
+      for (int i = 0; i < array->rank; i++)
+	if (mpz_cmp_si (array->shape[i], 0) <= 0)
+	  return true;
 
-  gfc_free_expr (e);
+      return false;
+    }
+
+  if (array->expr_type == EXPR_ARRAY)
+    return array->value.constructor == NULL;
 
-  return t;
+  return false;
 }
 
 
@@ -974,7 +976,7 @@ gfc_simplify_aint (gfc_expr *e, gfc_expr *k)
 gfc_expr *
 gfc_simplify_all (gfc_expr *mask, gfc_expr *dim)
 {
-  if (is_size_zero_array (mask))
+  if (gfc_is_size_zero_array (mask))
     return gfc_get_logical_expr (mask->ts.kind, &mask->where, true);
 
   return simplify_transformation (mask, dim, NULL, true, gfc_and);
@@ -1066,7 +1068,7 @@ gfc_simplify_and (gfc_expr *x, gfc_expr *y)
 gfc_expr *
 gfc_simplify_any (gfc_expr *mask, gfc_expr *dim)
 {
-  if (is_size_zero_array (mask))
+  if (gfc_is_size_zero_array (mask))
     return gfc_get_logical_expr (mask->ts.kind, &mask->where, false);
 
   return simplify_transformation (mask, dim, NULL, false, gfc_or);
@@ -1965,7 +1967,7 @@ gfc_simplify_count (gfc_expr *mask, gfc_expr *dim, gfc_expr *kind)
 {
   gfc_expr *result;
 
-  if (is_size_zero_array (mask))
+  if (gfc_is_size_zero_array (mask))
     {
       int k;
       k = kind ? mpz_get_si (kind->value.integer) : gfc_default_integer_kind;
@@ -3263,7 +3265,7 @@ do_bit_and (gfc_expr *result, gfc_expr *e)
 gfc_expr *
 gfc_simplify_iall (gfc_expr *array, gfc_expr *dim, gfc_expr *mask)
 {
-  if (is_size_zero_array (array))
+  if (gfc_is_size_zero_array (array))
     return gfc_get_int_expr (array->ts.kind, NULL, -1);
 
   return simplify_transformation (array, dim, mask, -1, do_bit_and);
@@ -3285,7 +3287,7 @@ do_bit_ior (gfc_expr *result, gfc_expr *e)
 gfc_expr *
 gfc_simplify_iany (gfc_expr *array, gfc_expr *dim, gfc_expr *mask)
 {
-  if (is_size_zero_array (array))
+  if (gfc_is_size_zero_array (array))
     return gfc_get_int_expr (array->ts.kind, NULL, 0);
 
   return simplify_transformation (array, dim, mask, 0, do_bit_ior);
@@ -3728,7 +3730,7 @@ do_bit_xor (gfc_expr *result, gfc_expr *e)
 gfc_expr *
 gfc_simplify_iparity (gfc_expr *array, gfc_expr *dim, gfc_expr *mask)
 {
-  if (is_size_zero_array (array))
+  if (gfc_is_size_zero_array (array))
     return gfc_get_int_expr (array->ts.kind, NULL, 0);
 
   return simplify_transformation (array, dim, mask, 0, do_bit_xor);
@@ -5038,7 +5040,7 @@ gfc_min (gfc_expr *op1, gfc_expr *op2)
 gfc_expr *
 gfc_simplify_minval (gfc_expr *array, gfc_expr* dim, gfc_expr *mask)
 {
-  if (is_size_zero_array (array))
+  if (gfc_is_size_zero_array (array))
     {
       gfc_expr *result;
       int i;
@@ -5094,7 +5096,7 @@ gfc_max (gfc_expr *op1, gfc_expr *op2)
 gfc_expr *
 gfc_simplify_maxval (gfc_expr *array, gfc_expr* dim, gfc_expr *mask)
 {
-  if (is_size_zero_array (array))
+  if (gfc_is_size_zero_array (array))
     {
       gfc_expr *result;
       int i;
@@ -5776,7 +5778,7 @@ gfc_simplify_norm2 (gfc_expr *e, gfc_expr *dim)
 {
   gfc_expr *result;
 
-  if (is_size_zero_array (e))
+  if (gfc_is_size_zero_array (e))
     {
       gfc_expr *result;
       result = gfc_get_constant_expr (e->ts.type, e->ts.kind, &e->where);
@@ -6040,7 +6042,7 @@ gfc_simplify_precision (gfc_expr *e)
 gfc_expr *
 gfc_simplify_product (gfc_expr *array, gfc_expr *dim, gfc_expr *mask)
 {
-  if (is_size_zero_array (array))
+  if (gfc_is_size_zero_array (array))
     {
       gfc_expr *result;
 
@@ -7384,7 +7386,7 @@ gfc_simplify_sqrt (gfc_expr *e)
 gfc_expr *
 gfc_simplify_sum (gfc_expr *array, gfc_expr *dim, gfc_expr *mask)
 {
-  if (is_size_zero_array (array))
+  if (gfc_is_size_zero_array (array))
     {
       gfc_expr *result;
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9ca476fdef5..0a41eaa7585 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2017-03-06  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/84697
+	PR fortran/66128
+	* gfortran.dg/minmaxloc_zerosize_1.f90: New test.
+
 2018-03-06  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/84684
diff --git a/gcc/testsuite/gfortran.dg/minmaxloc_zerosize_1.f90 b/gcc/testsuite/gfortran.dg/minmaxloc_zerosize_1.f90
new file mode 100644
index 00000000000..94e5d00b064
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/minmaxloc_zerosize_1.f90
@@ -0,0 +1,28 @@
+! { dg-do  run }
+! { dg-additional-options "-fdump-tree-original" }
+program main
+  implicit none
+  integer, parameter :: z(0) = 0
+  integer, parameter, dimension(1) :: a = minloc(z)
+  integer, parameter, dimension(1) :: b = minloc(z,mask=z>0)
+  integer, parameter :: c = minloc(z,dim=1)
+
+  integer, parameter, dimension(1) :: d = maxloc(z)
+  integer, parameter, dimension(1) :: e = maxloc(z,mask=z>0)
+  integer, parameter :: f = maxloc(z,dim=1)
+
+  character(len=12) line
+
+  if (a(1) /= 0) stop 1
+  if (b(1) /= 0) stop 2
+  if (c /= 0) stop 3
+
+  if (d(1) /= 0) stop 4
+  if (e(1) /= 0) stop 5
+  if (f /= 0) stop 6
+
+  write (unit=line,fmt='(6I2)') minloc(z), minloc(z,mask=z>0), minloc(z,dim=1), &
+       maxloc(z), maxloc(z,mask=z<0), maxloc(z,dim=1)
+  if (line /= ' 0 0 0 0 0 0') stop 7
+end program main
+! { dg-final { scan-tree-dump-times "_gfortran_stop" 1 "original" } }