1 files changed, 40 insertions, 6 deletions

diff --git a/Python/compile.c b/Python/compile.c
index 0e16075852..25179faa3e 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -1040,6 +1040,8 @@ PyCompile_OpcodeStackEffect(int opcode, int oparg)
             return -oparg;
         case CALL_FUNCTION:
             return -oparg;
+        case CALL_METHOD:
+            return -oparg-1;
         case CALL_FUNCTION_KW:
             return -oparg-1;
         case CALL_FUNCTION_EX:
@@ -1078,6 +1080,8 @@ PyCompile_OpcodeStackEffect(int opcode, int oparg)
             /* If there's a fmt_spec on the stack, we go from 2->1,
                else 1->1. */
             return (oparg & FVS_MASK) == FVS_HAVE_SPEC ? -1 : 0;
+        case LOAD_METHOD:
+            return 1;
         default:
             return PY_INVALID_STACK_EFFECT;
     }
@@ -3348,11 +3352,8 @@ compiler_dict(struct compiler *c, expr_ty e)
     /* If there is more than one dict, they need to be merged into a new
      * dict.  If there is one dict and it's an unpacking, then it needs
      * to be copied into a new dict." */
-    while (containers > 1 || is_unpacking) {
-        int oparg = containers < 255 ? containers : 255;
-        ADDOP_I(c, BUILD_MAP_UNPACK, oparg);
-        containers -= (oparg - 1);
-        is_unpacking = 0;
+    if (containers > 1 || is_unpacking) {
+        ADDOP_I(c, BUILD_MAP_UNPACK, containers);
     }
     return 1;
 }
@@ -3403,8 +3404,41 @@ compiler_compare(struct compiler *c, expr_ty e)
 }
 
 static int
+maybe_optimize_method_call(struct compiler *c, expr_ty e)
+{
+    Py_ssize_t argsl, i;
+    expr_ty meth = e->v.Call.func;
+    asdl_seq *args = e->v.Call.args;
+
+    /* Check that the call node is an attribute access, and that
+       the call doesn't have keyword parameters. */
+    if (meth->kind != Attribute_kind || meth->v.Attribute.ctx != Load ||
+            asdl_seq_LEN(e->v.Call.keywords))
+        return -1;
+
+    /* Check that there are no *varargs types of arguments. */
+    argsl = asdl_seq_LEN(args);
+    for (i = 0; i < argsl; i++) {
+        expr_ty elt = asdl_seq_GET(args, i);
+        if (elt->kind == Starred_kind) {
+            return -1;
+        }
+    }
+
+    /* Alright, we can optimize the code. */
+    VISIT(c, expr, meth->v.Attribute.value);
+    ADDOP_NAME(c, LOAD_METHOD, meth->v.Attribute.attr, names);
+    VISIT_SEQ(c, expr, e->v.Call.args);
+    ADDOP_I(c, CALL_METHOD, asdl_seq_LEN(e->v.Call.args));
+    return 1;
+}
+
+static int
 compiler_call(struct compiler *c, expr_ty e)
 {
+    if (maybe_optimize_method_call(c, e) > 0)
+        return 1;
+
     VISIT(c, expr, e->v.Call.func);
     return compiler_call_helper(c, 0,
                                 e->v.Call.args,
@@ -4044,7 +4078,7 @@ compiler_visit_keyword(struct compiler *c, keyword_ty k)
 static int
 expr_constant(struct compiler *c, expr_ty e)
 {
-    char *id;
+    const char *id;
     switch (e->kind) {
     case Ellipsis_kind:
         return 1;