From 71d49a20a7f76602501e274cc089758b58d225ce Mon Sep 17 00:00:00 2001
From: Graydon Hoare <graydon@mozilla.com>
Date: Tue, 21 Sep 2010 00:13:59 -0700
Subject: Skip 0-ary tag ctors in Trans.iter_tag_parts. Rustc loses 150kb.

---
 src/boot/me/trans.ml | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

(limited to 'src')

diff --git a/src/boot/me/trans.ml b/src/boot/me/trans.ml
index ba0c4771..e70c3196 100644
--- a/src/boot/me/trans.ml
+++ b/src/boot/me/trans.ml
@@ -2715,18 +2715,24 @@ let trans_visitor
       mov tmp (Il.Cell src_tag);
       for i = 0 to n-1
       do
-        (iflog (fun _ ->
-                  annotate (Printf.sprintf "tag case #%i" i)));
-        let jmps =
-          trans_compare_simple Il.JNE (Il.Cell tmp) (imm (Int64.of_int i))
-        in
         let ttup = get_nth_tag_tup cx ttag i in
-          iter_tup_parts
-            (get_element_ptr_dyn ty_params)
-            (get_variant_ptr dst_union i)
-            (get_variant_ptr src_union i)
-            ttup f;
-          List.iter patch jmps
+          if Array.length ttup <> 0
+          then
+            begin
+              (iflog (fun _ ->
+                        annotate (Printf.sprintf "tag case #%i" i)));
+              let jmps =
+                trans_compare_simple Il.JNE
+                  (Il.Cell tmp) (imm (Int64.of_int i))
+              in
+              let ttup = get_nth_tag_tup cx ttag i in
+                iter_tup_parts
+                  (get_element_ptr_dyn ty_params)
+                  (get_variant_ptr dst_union i)
+                  (get_variant_ptr src_union i)
+                  ttup f;
+                List.iter patch jmps
+            end
       done;
 
   and seq_unit_ty (seq:Ast.ty) : Ast.ty =
-- 
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