transforms/inline: implement 'portable' decorator

artiq/transforms/inline.py

@@ -122,7 +122,7 @@ class _ReferenceManager:
             raise NotImplementedError
 
 
-_embeddable_calls = (
+_embeddable_funcs = (
     core_language.delay, core_language.at, core_language.now,
     core_language.time_to_cycles, core_language.cycles_to_time,
     core_language.syscall,
@@ -131,13 +131,22 @@ _embeddable_calls = (
     Fraction, units.Quantity, core_language.EncodedException
 )
 
-def _is_embeddable(call):
-    for ec in _embeddable_calls:
-        if call is ec:
+def _is_embeddable(func):
+    for ef in _embeddable_funcs:
+        if func is ef:
             return True
     return False
 
 
+def _is_inlinable(core, func):
+    if hasattr(func, "k_function_info"):
+        if func.k_function_info.core_name == "":
+            return True  # portable function
+        if getattr(func.__self__, func.k_function_info.core_name) is core:
+            return True  # kernel function for the same core device
+    return False
+
+
 class _ReferenceReplacer(ast.NodeVisitor):
     def __init__(self, core, rm, obj, func_name, retval_name):
         self.core = core
@@ -231,9 +240,7 @@ class _ReferenceReplacer(ast.NodeVisitor):
                 ast.Call(func=new_func, args=new_args,
                          keywords=[], starargs=None, kwargs=None),
                 node)
-        elif (hasattr(func, "k_function_info")
-              and getattr(func.__self__, func.k_function_info.core_name)
-                is self.core):
+        elif _is_inlinable(self.core, func):
             retval_name = self.rm.new_name(
                 func.k_function_info.k_function.__name__ + "_return")
             args = [func.__self__] + new_args