From 6555d89c2c7f403a45800903457ee62a62ff327a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Arne=20D=C3=B6ring?= <arne.doering@gmx.net>
Date: Thu, 24 Jan 2019 11:33:44 +0100
Subject: [PATCH] free some registers after usage, allows more complex macros
 (#10443)

---
 compiler/vmgen.nim | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/compiler/vmgen.nim b/compiler/vmgen.nim
index e7993dfb2..f87821da4 100644
--- a/compiler/vmgen.nim
+++ b/compiler/vmgen.nim
@@ -326,8 +326,14 @@ proc genWhile(c: PCtx; n: PNode) =
       c.patch(L2)
 
 proc genBlock(c: PCtx; n: PNode; dest: var TDest) =
+  let oldRegisterCount = c.prc.maxSlots
   withBlock(n.sons[0].sym):
     c.gen(n.sons[1], dest)
+
+  for i in oldRegisterCount ..< c.prc.maxSlots:
+    if c.prc.slots[i].kind in {slotFixedVar, slotFixedLet}:
+      c.prc.slots[i] = (inUse: false, kind: slotEmpty)
+
   c.clearDest(n, dest)
 
 proc genBreak(c: PCtx; n: PNode) =