[patch, fortran] Some more corrections to zero-size simplification

[Thomas Koenig <tkoenig at netcologne dot de>]

Hello world,

the attached patch fixes a few corner cases of a corner case in
simplification, i.e. empty arrays where array intrinsics can actually
have a non-empty array result.

Regression-tested. OK for trunk?

Regards

	Thomas

2017-06-11  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR fortran/66128
        * simplify.c (simplify_transformation): Return default result for
        empty array argument.
        (gfc_simplify_all): Remove special-case handling for zerosize.
        (gfc_simplify_any): Likewise.
        (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_norm2): Likewise.
        (gfc_simplify_product): Likewise.
        (gfc_simplify_sum): Likewise.

2017-06-11  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR fortran/66128
        * gfortran.dg/zero_sized_9.f90: New test.

! { dg-do  run }
program main
  implicit none
  integer, parameter :: a(0,3) = 0
  integer, parameter :: b(3,0) = -42
  integer, parameter, dimension(3) :: a1 = minval(a,dim=1)
  integer, parameter, dimension(0) :: a2 = minval(a,dim=2)
  integer, parameter, dimension(0) :: b1 = minval(b,dim=1)
  integer, parameter, dimension(3) :: b2 = minval(b,dim=2)
  logical, parameter :: c(0,3) = .false.
  logical, parameter :: d(3,0) = .false.
  logical, parameter, dimension(3) :: tr = all(c,dim=1)
  logical, parameter, dimension(3) :: fa = any(c,dim=1)
  integer, parameter, dimension(3) :: ze = count(d,dim=2)
  integer, parameter, dimension(3) :: ze2 = iany(b,dim=2)
  integer, parameter, dimension(3) :: ze3 = iparity(a,dim=1)
  real, parameter, dimension(0,3) :: r = 1.0
  real, parameter, dimension(3) :: n2 = norm2(r,dim=1)
  integer, parameter, dimension(3) :: one = product(b,dim=2)
  integer, parameter, dimension(3) :: ze4 = sum(a,dim=1)
  if (any(a1 /= huge(0))) stop 1
  if (any(b2 /= huge(b2))) stop 2
  if (any(.not.tr)) stop 3
  if (any(fa)) stop 3
  if (any(ze /= 0)) stop 4
  if (any(ze2 /= 0)) stop 5
  if (any(ze3 /= 0)) stop 6
  if (any(n2 /= 0.0)) stop 7
  if (any(one /= 1)) stop 8
  if (any(ze4 /= 0)) stop 9
end program main

Index: simplify.c
===================================================================
--- simplify.c	(Revision 258433)
+++ simplify.c	(Arbeitskopie)
@@ -689,8 +689,11 @@ simplify_transformation (gfc_expr *array, gfc_expr
 			 int init_val, transformational_op op)
 {
   gfc_expr *result;
+  bool size_zero;
 
-  if (!is_constant_array_expr (array)
+  size_zero = gfc_is_size_zero_array (array);
+
+  if (!(is_constant_array_expr (array) || size_zero)
       || !gfc_is_constant_expr (dim))
     return NULL;
 
@@ -703,6 +706,9 @@ simplify_transformation (gfc_expr *array, gfc_expr
 				    array->ts.kind, &array->where);
   init_result_expr (result, init_val, array);
 
+  if (size_zero)
+    return result;
+
   return !dim || array->rank == 1 ?
     simplify_transformation_to_scalar (result, array, mask, op) :
     simplify_transformation_to_array (result, array, dim, mask, op, NULL);
@@ -976,9 +982,6 @@ gfc_simplify_aint (gfc_expr *e, gfc_expr *k)
 gfc_expr *
 gfc_simplify_all (gfc_expr *mask, gfc_expr *dim)
 {
-  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);
 }
 
@@ -1068,9 +1071,6 @@ gfc_simplify_and (gfc_expr *x, gfc_expr *y)
 gfc_expr *
 gfc_simplify_any (gfc_expr *mask, gfc_expr *dim)
 {
-  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);
 }
 
@@ -1966,15 +1966,11 @@ gfc_expr *
 gfc_simplify_count (gfc_expr *mask, gfc_expr *dim, gfc_expr *kind)
 {
   gfc_expr *result;
+  bool size_zero;
 
-  if (gfc_is_size_zero_array (mask))
-    {
-      int k;
-      k = kind ? mpz_get_si (kind->value.integer) : gfc_default_integer_kind;
-      return gfc_get_int_expr (k, NULL, 0);
-    }
+  size_zero = gfc_is_size_zero_array (mask);
 
-  if (!is_constant_array_expr (mask)
+  if (!(is_constant_array_expr (mask) || size_zero)
       || !gfc_is_constant_expr (dim)
       || !gfc_is_constant_expr (kind))
     return NULL;
@@ -1987,6 +1983,9 @@ gfc_simplify_count (gfc_expr *mask, gfc_expr *dim,
 
   init_result_expr (result, 0, NULL);
 
+  if (size_zero)
+    return result;
+
   /* Passing MASK twice, once as data array, once as mask.
      Whenever gfc_count is called, '1' is added to the result.  */
   return !dim || mask->rank == 1 ?
@@ -3265,9 +3264,6 @@ do_bit_and (gfc_expr *result, gfc_expr *e)
 gfc_expr *
 gfc_simplify_iall (gfc_expr *array, gfc_expr *dim, gfc_expr *mask)
 {
-  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);
 }
 
@@ -3287,9 +3283,6 @@ do_bit_ior (gfc_expr *result, gfc_expr *e)
 gfc_expr *
 gfc_simplify_iany (gfc_expr *array, gfc_expr *dim, gfc_expr *mask)
 {
-  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);
 }
 
@@ -3730,9 +3723,6 @@ do_bit_xor (gfc_expr *result, gfc_expr *e)
 gfc_expr *
 gfc_simplify_iparity (gfc_expr *array, gfc_expr *dim, gfc_expr *mask)
 {
-  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);
 }
 
@@ -5040,43 +5030,6 @@ gfc_min (gfc_expr *op1, gfc_expr *op2)
 gfc_expr *
 gfc_simplify_minval (gfc_expr *array, gfc_expr* dim, gfc_expr *mask)
 {
-  if (gfc_is_size_zero_array (array))
-    {
-      gfc_expr *result;
-      int i;
-
-      i = gfc_validate_kind (array->ts.type, array->ts.kind, false);
-      result = gfc_get_constant_expr (array->ts.type, array->ts.kind,
-				      &array->where);
-      switch (array->ts.type)
-	{
-	  case BT_INTEGER:
-	    mpz_set (result->value.integer, gfc_integer_kinds[i].huge);
-	    break;
-
-	  case BT_REAL:
-	    mpfr_set (result->value.real, gfc_real_kinds[i].huge, GFC_RND_MODE);
-	    break;
-
-	  case BT_CHARACTER:
-	    /* If ARRAY has size zero and type character, the result has the
-	       value of a string of characters of length LEN (ARRAY), with
-	       each character equal to CHAR(n - 1, KIND (ARRAY)), where n is
-	       the number of characters in the collating sequence for
-	       characters with the kind type parameter of ARRAY.  */
-	    gfc_error ("MINVAL(string) at %L is not implemented, yet!",
-			&array->where);
-	    gfc_free_expr (result);
-	    return &gfc_bad_expr;
-	    break;
-
-	  default:
-	    gcc_unreachable ();
-    	}
-
-      return result;
-    }
-
   return simplify_transformation (array, dim, mask, INT_MAX, gfc_min);
 }
 
@@ -5096,42 +5049,6 @@ gfc_max (gfc_expr *op1, gfc_expr *op2)
 gfc_expr *
 gfc_simplify_maxval (gfc_expr *array, gfc_expr* dim, gfc_expr *mask)
 {
-  if (gfc_is_size_zero_array (array))
-    {
-      gfc_expr *result;
-      int i;
-
-      i = gfc_validate_kind (array->ts.type, array->ts.kind, false);
-      result = gfc_get_constant_expr (array->ts.type, array->ts.kind,
-				      &array->where);
-      switch (array->ts.type)
-	{
-	  case BT_INTEGER:
-	    mpz_set (result->value.integer, gfc_integer_kinds[i].min_int);
-	    break;
-
-	  case BT_REAL:
-	    mpfr_set (result->value.real, gfc_real_kinds[i].huge, GFC_RND_MODE);
-	    mpfr_neg (result->value.real, result->value.real,  GFC_RND_MODE);
-	    break;
-
-	  case BT_CHARACTER:
-	    /* If ARRAY has size zero and type character, the result has the
-               value of a string of characters of length LEN (ARRAY), with
-               each character equal to CHAR (0, KIND (ARRAY)).  */
-	    gfc_error ("MAXVAL(string) at %L is not implemented, yet!",
-			&array->where);
-	    gfc_free_expr (result);
-	    return &gfc_bad_expr;
-	    break;
-
-	  default:
-	    gcc_unreachable ();
-    	}
-
-      return result;
-    }
-
   return simplify_transformation (array, dim, mask, INT_MIN, gfc_max);
 }
 
@@ -5777,16 +5694,11 @@ gfc_expr *
 gfc_simplify_norm2 (gfc_expr *e, gfc_expr *dim)
 {
   gfc_expr *result;
+  bool size_zero;
 
-  if (gfc_is_size_zero_array (e))
-    {
-      gfc_expr *result;
-      result = gfc_get_constant_expr (e->ts.type, e->ts.kind, &e->where);
-      mpfr_set_ui (result->value.real, 0, GFC_RND_MODE);
-      return result;
-    }
+  size_zero = gfc_is_size_zero_array (e);
 
-  if (!is_constant_array_expr (e)
+  if (!(is_constant_array_expr (e) || size_zero)
       || (dim != NULL && !gfc_is_constant_expr (dim)))
     return NULL;
 
@@ -5793,6 +5705,9 @@ gfc_simplify_norm2 (gfc_expr *e, gfc_expr *dim)
   result = transformational_result (e, dim, e->ts.type, e->ts.kind, &e->where);
   init_result_expr (result, 0, NULL);
 
+  if (size_zero)
+    return result;
+
   if (!dim || e->rank == 1)
     {
       result = simplify_transformation_to_scalar (result, e, NULL,
@@ -6042,33 +5957,6 @@ gfc_simplify_precision (gfc_expr *e)
 gfc_expr *
 gfc_simplify_product (gfc_expr *array, gfc_expr *dim, gfc_expr *mask)
 {
-  if (gfc_is_size_zero_array (array))
-    {
-      gfc_expr *result;
-
-      result = gfc_get_constant_expr (array->ts.type, array->ts.kind,
-				      &array->where);
-      switch (array->ts.type)
-	{
-	  case BT_INTEGER:
-	    mpz_set_ui (result->value.integer, 1);
-	    break;
-
-	  case BT_REAL:
-	    mpfr_set_ui (result->value.real, 1, GFC_RND_MODE);
-	    break;
-
-	  case BT_COMPLEX:
-	    mpc_set_ui (result->value.complex, 1, GFC_MPC_RND_MODE);
-	    break;
-
-	  default:
-	    gcc_unreachable ();
-    	}
-
-      return result;
-    }
-
   return simplify_transformation (array, dim, mask, 1, gfc_multiply);
 }
 
@@ -7386,33 +7274,6 @@ gfc_simplify_sqrt (gfc_expr *e)
 gfc_expr *
 gfc_simplify_sum (gfc_expr *array, gfc_expr *dim, gfc_expr *mask)
 {
-  if (gfc_is_size_zero_array (array))
-    {
-      gfc_expr *result;
-
-      result = gfc_get_constant_expr (array->ts.type, array->ts.kind,
-				      &array->where);
-      switch (array->ts.type)
-	{
-	  case BT_INTEGER:
-	    mpz_set_ui (result->value.integer, 0);
-	    break;
-
-	  case BT_REAL:
-	    mpfr_set_ui (result->value.real, 0, GFC_RND_MODE);
-	    break;
-
-	  case BT_COMPLEX:
-	    mpc_set_ui (result->value.complex, 0, GFC_MPC_RND_MODE);
-	    break;
-
-	  default:
-	    gcc_unreachable ();
-    	}
-
-      return result;
-    }
-
   return simplify_transformation (array, dim, mask, 0, gfc_add);
 }