From 789c452ee6777386e465ad66fa58084a6d5ccd20 Mon Sep 17 00:00:00 2001
From: Yiannis Tsiouris <gtsiour@softlab.ntua.gr>
Date: Sat, 29 Mar 2014 02:38:27 +0200
Subject: [PATCH] Simplify fix_sdescs by removing redundant check

---
 lib/hipe/llvm/hipe_llvm_main.erl | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/lib/hipe/llvm/hipe_llvm_main.erl b/lib/hipe/llvm/hipe_llvm_main.erl
index 936e47aedb15..f068e34680d8 100644
--- a/lib/hipe/llvm/hipe_llvm_main.erl
+++ b/lib/hipe/llvm/hipe_llvm_main.erl
@@ -427,25 +427,21 @@ find_offsets([{Off,Arity}|Rest], Offsets, Acc) ->
   [I | RestOffsets] = lists:dropwhile(fun (Y) -> Y<Off end, Offsets),
   find_offsets(Rest, RestOffsets, [{I, Arity}|Acc]).
 
-%% The function below corrects the arity of calls, that are identified
-%% by offset, in the stack descriptors.
+%% The function below corrects the stack descriptors of calls with arguments
+%% that are passed on the stack (more the NR_ARG_REGS) by subtracting the
+%% number of stacked arguments from the frame size and from the offset of the
+%% roots.
 fix_sdescs([], SDescs) -> SDescs;
 fix_sdescs([{Offset, Arity} | Rest], SDescs) ->
   case lists:keyfind(Offset, 2, SDescs) of
     false ->
       fix_sdescs(Rest, SDescs);
-    {?SDESC, Offset, SDesc} ->
-      {ExnHandler, FrameSize, StkArity, Roots} = SDesc,
+    {?SDESC, Offset, {ExnHandler, FrameSize, StkArity, Roots}} ->
       FixedRoots = [X - Arity || X <- tuple_to_list(Roots)],
-      NewRoots =
-        case FixedRoots of
-          [H|_] when H >= 0 -> list_to_tuple(FixedRoots);
-          _ -> Roots
-        end,
-      NewSDesc =
-        {?SDESC, Offset, {ExnHandler, FrameSize - Arity, StkArity, NewRoots}},
+      FixedSDesc =
+        {?SDESC, Offset, {ExnHandler, FrameSize - Arity, StkArity, FixedRoots}},
       RestSDescs = lists:keydelete(Offset, 2, SDescs),
-      fix_sdescs(Rest, [NewSDesc | RestSDescs])
+      fix_sdescs(Rest, [FixedSDesc | RestSDescs])
   end.