#1960 tidying for review and simplifying tenerated expressions where …

…poss. [skip ci]

src/psyclone/psyir/frontend/fparser2.py

@@ -3673,11 +3673,19 @@ def _array_syntax_to_indexed(self, parent, loop_vars):
                              ("dim", Literal(str(idx+1), INTEGER_TYPE))])
                     else:
                         lbound = shape[range_idx].lower.copy()
-                    # Create the index expression:
-                    #    idx-expr = array-lower-bound + loop-idx - 1
-                    expr = BinaryOperation.create(
-                        add_op, lbound, Reference(symbol))
-                    expr2 = BinaryOperation.create(sub_op, expr, one.copy())
+                    # Create the index expression.
+                    if isinstance(lbound, Literal) and lbound.value == "1":
+                        # Lower bound is just unity so we can use the loop-idx
+                        # directly.
+                        expr2 = Reference(symbol)
+                    else:
+                        # We don't know what the lower bound is so have to
+                        # have an expression:
+                        #    idx-expr = array-lower-bound + loop-idx - 1
+                        expr = BinaryOperation.create(
+                            add_op, lbound, Reference(symbol))
+                        expr2 = BinaryOperation.create(sub_op, expr,
+                                                       one.copy())
                     array.children[idx] = expr2
                     range_idx += 1
 
@@ -3850,7 +3858,7 @@ def _contains_intrinsic_reduction(pnodes):
             # Point to the original WHERE statement in the parse tree.
             loop.ast = node
 
-            # This loop is over the shape of the mask and thus starts
+            # This loop is over the *shape* of the mask and thus starts
             # at unity. Each individual array access is then adjusted
             # according to the lower bound of that array.
             loop.addchild(Literal("1", integer_type))

src/psyclone/psyir/nodes/array_mixin.py

@@ -546,10 +546,23 @@ def _num_elements(expr):
                 start = expr.lower
                 stop = expr.upper
                 step = Literal("1", INTEGER_TYPE)
-            minus = BinaryOperation.create(BinaryOperation.Operator.SUB,
-                                           stop.copy(), start.copy())
+            if (isinstance(start, IntrinsicCall) and
+                    start.intrinsic == IntrinsicCall.Intrinsic.LBOUND and
+                    isinstance(stop, IntrinsicCall) and
+                    stop.intrinsic == IntrinsicCall.Intrinsic.UBOUND and
+                    isinstance(start.children[0], Reference) and
+                    isinstance(stop.children[0], Reference) and
+                    start.children[0].symbol is stop.children[0].symbol and
+                    start.children[1] == stop.children[1]):
+                extent = IntrinsicCall.create(
+                    IntrinsicCall.Intrinsic.SIZE,
+                    [stop.children[0].copy(),
+                     ("dim", stop.children[1].copy())])
+            else:
+                extent = BinaryOperation.create(BinaryOperation.Operator.SUB,
+                                                stop.copy(), start.copy())
             div = BinaryOperation.create(BinaryOperation.Operator.DIV,
-                                         minus, step.copy())
+                                         extent, step.copy())
             plus = BinaryOperation.create(BinaryOperation.Operator.ADD,
                                           div, Literal("1", INTEGER_TYPE))
             return plus

src/psyclone/tests/psyir/frontend/fparser2_where_handler_test.py

@@ -327,7 +327,7 @@ def test_where_within_loop(fortran_reader):
     assert isinstance(where_loop.loop_body[0], IfBlock)
     assign = where_loop.loop_body[0].if_body[0]
     assert isinstance(assign, Assignment)
-    assert assign.lhs.indices[0].debug_string() == "1 + widx1 - 1"
+    assert assign.lhs.indices[0].debug_string() == "widx1"
     assert assign.lhs.indices[1].debug_string() == "jl"
     assert where_loop.start_expr.value == "1"
     assert (where_loop.stop_expr.debug_string() ==
@@ -359,7 +359,7 @@ def test_basic_where():
     assert isinstance(ifblock, IfBlock)
     assert "was_where" in ifblock.annotations
     assert (ifblock.condition.debug_string() ==
-            "dry(1 + widx1 - 1,1 + widx2 - 1,1 + widx3 - 1)")
+            "dry(widx1,widx2,widx3)")
 
 
 @pytest.mark.usefixtures("parser")
@@ -384,9 +384,9 @@ def test_where_array_subsections():
     # Check that the array reference is indexed correctly
     assign = ifblock.if_body[0]
     assert isinstance(assign, Assignment)
-    assert isinstance(assign.lhs.children[0], BinaryOperation)
-    assert assign.lhs.children[0].debug_string() == "1 + widx1 - 1"
-    assert assign.lhs.children[2].debug_string() == "1 + widx2 - 1"
+    assert isinstance(assign.lhs.children[0], Reference)
+    assert assign.lhs.children[0].debug_string() == "widx1"
+    assert assign.lhs.children[2].debug_string() == "widx2"
 
 
 def test_where_body_containing_sum_with_dim(fortran_reader, fortran_writer):
@@ -539,7 +539,7 @@ def test_elsewhere():
     assert isinstance(ifblock.condition, BinaryOperation)
     assert ifblock.condition.operator == BinaryOperation.Operator.GT
     assert (ifblock.condition.debug_string() ==
-            "ptsu(1 + widx1 - 1,1 + widx2 - 1,1 + widx3 - 1) > 10._wp")
+            "ptsu(widx1,widx2,widx3) > 10._wp")
     # Check that this IF block has an else body which contains another IF
     assert ifblock.else_body is not None
     ifblock2 = ifblock.else_body[0]
@@ -548,7 +548,7 @@ def test_elsewhere():
     assert isinstance(ifblock2.condition, BinaryOperation)
     assert ifblock2.condition.operator == BinaryOperation.Operator.LT
     assert (ifblock2.condition.debug_string() ==
-            "ptsu(1 + widx1 - 1,1 + widx2 - 1,1 + widx3 - 1) < 0.0_wp")
+            "ptsu(widx1,widx2,widx3) < 0.0_wp")
     # Check that this IF block too has an else body
     assert isinstance(ifblock2.else_body[0], Assignment)
     # Check that we have three assignments of the correct form and with the
@@ -560,7 +560,7 @@ def test_elsewhere():
         refs = assign.lhs.walk(Reference)
         assert len(refs) == 4
         assert (assign.lhs.debug_string() ==
-                "z1_st(1 + widx1 - 1,1 + widx2 - 1,1 + widx3 - 1)")
+                "z1_st(widx1,widx2,widx3)")
         assert isinstance(assign.parent.parent, IfBlock)
 
     assert isinstance(assigns[0].rhs, BinaryOperation)