py2llvm: len() support on lists

artiq/py2llvm/ast_body.py

@@ -167,7 +167,7 @@ class Visitor:
 
     def _visit_expr_Call(self, node):
         fn = node.func.id
-        if fn in {"bool", "int", "int64", "round", "round64", "float"}:
+        if fn in {"bool", "int", "int64", "round", "round64", "float", "len"}:
             value = self.visit_expression(node.args[0])
             return getattr(value, "o_" + fn)(self.builder)
         elif fn == "Fraction":

artiq/py2llvm/lists.py

@@ -1,6 +1,7 @@
 import llvmlite.ir as ll
 
 from artiq.py2llvm.values import VGeneric
+from artiq.py2llvm.base_types import VInt
 
 
 class VList(VGeneric):
@@ -40,6 +41,15 @@ class VList(VGeneric):
             ll.Constant(ll.IntType(32), 0)])
         builder.store(ll.Constant(ll.IntType(32), count), count_ptr)
 
+    def o_len(self, builder):
+        r = VInt()
+        if builder is not None:
+            count_ptr = builder.gep(self.llvm_value, [
+                ll.Constant(ll.IntType(32), 0),
+                ll.Constant(ll.IntType(32), 0)])
+            r.auto_store(builder, builder.load(count_ptr))
+        return r
+
     def o_subscript(self, index, builder):
         r = self.el_type.new()
         if builder is not None:

artiq/test/full_stack.py

@@ -61,7 +61,7 @@ class _Misc(AutoContext):
         self.inhomogeneous_units.append(Quantity(1000, "Hz"))
         self.inhomogeneous_units.append(Quantity(10, "s"))
         self.acc = 0
-        for i in range(5):
+        for i in range(len(self.al)):
             self.acc += self.al[i]
 
     @kernel

artiq/transforms/tools.py

@@ -9,7 +9,7 @@ embeddable_funcs = (
     core_language.delay, core_language.at, core_language.now,
     core_language.time_to_cycles, core_language.cycles_to_time,
     core_language.syscall,
-    range, bool, int, float, round,
+    range, bool, int, float, round, len,
     core_language.int64, core_language.round64,
     Fraction, units.Quantity, units.check_unit, core_language.EncodedException
 )