From aba9cfb2a85dd42f22f6784a418f9b7c82b82d69 Mon Sep 17 00:00:00 2001
From: Michael Munday <munday@ca.ibm.com>
Date: Wed, 28 Dec 2016 10:56:09 -0500
Subject: [PATCH] Implement UGET.

Allows simple closures, for example:

function f(x)
  return function() return x end
end

y = f(1)
print(y()) -- prints 1
---
 src/vm_s390x.dasc | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/vm_s390x.dasc b/src/vm_s390x.dasc
index c862e427..7754c45f 100644
--- a/src/vm_s390x.dasc
+++ b/src/vm_s390x.dasc
@@ -1970,8 +1970,16 @@ static void build_ins(BuildCtx *ctx, BCOp op, int defop)
     |  stg r0, 0(r0)
     break;
   case BC_UGET:
-    |  stg r0, 0(r0)
-    |  stg r0, 0(r0)
+    |  ins_AD	// RA = dst, RD = upvalue #
+    |  sllg RA, RA, 3(r0)
+    |  sllg RD, RD, 3(r0)
+    |  lg LFUNC:RB, -16(BASE)
+    |  cleartp LFUNC:RB
+    |  lg UPVAL:RB, (offsetof(GCfuncL, uvptr))(RD, LFUNC:RB)
+    |  lg RB, UPVAL:RB->v
+    |  lg RD, 0(RB)
+    |  stg RD, 0(RA, BASE)
+    |  ins_next
     break;
   case BC_USETV:
     |  stg r0, 0(r0)