diff --git a/loopy/kernel.py b/loopy/kernel.py
index 5add79c782e12ca14ca223903c5f759f2398e4c9..d1eb4edddd77f809b84bc6e4a4aa0cf78d1b826f 100644
--- a/loopy/kernel.py
+++ b/loopy/kernel.py
@@ -902,13 +902,23 @@ class LoopKernel(Record):
                         "instance or a parseable string. got '%s' instead."
                         % type(insn))
 
-            for insn in expand_defines(insn, defines, single_valued=False):
-                parse_insn(insn)
+            for insn in insn.split("\n"):
+                insn = insn.strip()
+
+                if not insn:
+                    continue
+                if insn.startswith("#"):
+                    continue
+
+                for sub_insn in expand_defines(insn, defines, single_valued=False):
+                    parse_insn(sub_insn)
 
         parsed_instructions = []
 
         substitutions = substitutions.copy()
 
+        if isinstance(instructions, str):
+            instructions = [instructions]
         for insn in instructions:
             # must construct list one-by-one to facilitate unique id generation
             parse_if_necessary(insn)
@@ -979,13 +989,15 @@ class LoopKernel(Record):
 
         processed_args = []
         for arg in args:
-            if isinstance(arg, _ShapedArg):
-                if arg.shape is not None:
-                    arg = arg.copy(shape=expand_defines_in_expr(arg.shape, defines))
-                if arg.strides is not None:
-                    arg = arg.copy(strides=expand_defines_in_expr(arg.strides, defines))
-
-            processed_args.append(arg)
+            for name in arg.name.split(","):
+                new_arg = arg.copy(name=name)
+                if isinstance(arg, _ShapedArg):
+                    if arg.shape is not None:
+                        new_arg = new_arg.copy(shape=expand_defines_in_expr(arg.shape, defines))
+                    if arg.strides is not None:
+                        new_arg = new_arg.copy(strides=expand_defines_in_expr(arg.strides, defines))
+
+                processed_args.append(new_arg)
 
         # }}}
 
diff --git a/test/test_linalg.py b/test/test_linalg.py
index 84878d97221fd3b062bd6d7393f216e8edae7b82..b6087f4429534d11748a6b307b1ae14ed237385e 100644
--- a/test/test_linalg.py
+++ b/test/test_linalg.py
@@ -273,9 +273,10 @@ def test_variable_size_matrix_mul(ctx_factory):
 def test_rank_one(ctx_factory):
     dtype = np.float32
     ctx = ctx_factory()
-    order = "C"
+    order = "F"
 
-    n = int(get_suitable_size(ctx)**(2.7/2))
+    #n = int(get_suitable_size(ctx)**(2.7/2))
+    n = 16**3
 
     knl = lp.make_kernel(ctx.devices[0],
             "[n] -> {[i,j]: 0<=i,j<n}",
@@ -288,7 +289,8 @@ def test_rank_one(ctx_factory):
                 lp.GlobalArg("c", dtype, shape=("n, n"), order=order),
                 lp.ValueArg("n", np.int32, approximately=n),
                 ],
-            name="rank_one", assumptions="n >= 16")
+            name="rank_one",
+            assumptions="n >= 16")
 
     def variant_1(knl):
         knl = lp.add_prefetch(knl, "a")
@@ -337,15 +339,15 @@ def test_rank_one(ctx_factory):
 
     seq_knl = knl
 
-    for variant in [variant_1, variant_2, variant_3, variant_4]:
-    #for variant in [variant_1]:
+    #for variant in [variant_1, variant_2, variant_3, variant_4]:
+    for variant in [variant_4]:
         kernel_gen = lp.generate_loop_schedules(variant(knl),
                 loop_priority=["i", "j"])
         kernel_gen = lp.check_kernels(kernel_gen, dict(n=n))
 
         lp.auto_test_vs_ref(seq_knl, ctx, kernel_gen,
                 op_count=[np.dtype(dtype).itemsize*n**2/1e9], op_label=["GBytes"],
-                parameters={"n": n})
+                parameters={"n": n}, edit_code=True, do_check=False)