From 7a59ebda66ac29702b8f83238eb350ce09269fe8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Kochma=C5=84ski?= <daniel@turtleware.eu>
Date: Sun, 16 Aug 2015 18:28:49 +0200
Subject: [PATCH] c_leta: don't compute whole list length for optimization
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This is interpreter performance tweak. Behavior stays the same.

Signed-off-by: Daniel Kochmański <daniel@turtleware.eu>
---
 src/c/compiler.d | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/c/compiler.d b/src/c/compiler.d
index ff76d899f..31c3d9122 100644
--- a/src/c/compiler.d
+++ b/src/c/compiler.d
@@ -1551,10 +1551,10 @@ c_let_leta(cl_env_ptr env, int op, cl_object args, int flags) {
         specials = env->values[3];
 
         /* Optimize some common cases */
-        switch(ecl_length(bindings)) {
-        case 0:         return c_locally(env, CDR(args), flags);
-        case 1:         op = OP_BIND; break;
-        }
+        if (bindings == ECL_NIL)
+                return c_locally(env, CDR(args), flags);
+        if (ECL_CONS_CDR(bindings) == ECL_NIL)
+                op = OP_BIND;
 
         for (vars=ECL_NIL, l=bindings; !Null(l); ) {
                 cl_object aux = pop(&l);