From c9c5abcdc17daa3aeb583f4473925b6ea19b0d64 Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Sat, 23 Mar 2019 14:44:53 +0100
Subject: [PATCH] fixes #10886 [backport] (#10897)

(cherry picked from commit 0b2a3f6f7f7dfc40e08d287f41f7ce7c2e51fd9c)
---
 compiler/vmgen.nim   | 23 ++++++++++++++++-------
 tests/vm/tvmmisc.nim | 29 +++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/compiler/vmgen.nim b/compiler/vmgen.nim
index 2f96f60bc8..6cfc07446c 100644
--- a/compiler/vmgen.nim
+++ b/compiler/vmgen.nim
@@ -361,16 +361,28 @@ proc genIf(c: PCtx, n: PNode; dest: var TDest) =
   for endPos in endings: c.patch(endPos)
   c.clearDest(n, dest)
 
+proc isTemp(c: PCtx; dest: TDest): bool =
+  result = dest >= 0 and c.prc.slots[dest].kind >= slotTempUnknown
+
 proc genAndOr(c: PCtx; n: PNode; opc: TOpcode; dest: var TDest) =
   #   asgn dest, a
   #   tjmp|fjmp L1
   #   asgn dest, b
   # L1:
-  if dest < 0: dest = getTemp(c, n.typ)
-  c.gen(n.sons[1], dest)
-  let L1 = c.xjmp(n, opc, dest)
-  c.gen(n.sons[2], dest)
+  let copyBack = dest < 0 or not isTemp(c, dest)
+  let tmp = if copyBack:
+              getTemp(c, n.typ)
+            else:
+              TRegister dest
+  c.gen(n.sons[1], tmp)
+  let L1 = c.xjmp(n, opc, tmp)
+  c.gen(n.sons[2], tmp)
   c.patch(L1)
+  if dest < 0:
+    dest = tmp
+  elif copyBack:
+    c.gABC(n, opcAsgnInt, dest, tmp)
+    freeTemp(c, tmp)
 
 proc canonValue*(n: PNode): PNode =
   result = n
@@ -1396,9 +1408,6 @@ proc checkCanEval(c: PCtx; n: PNode) =
                   skIterator} and sfForward in s.flags:
     cannotEval(c, n)
 
-proc isTemp(c: PCtx; dest: TDest): bool =
-  result = dest >= 0 and c.prc.slots[dest].kind >= slotTempUnknown
-
 template needsAdditionalCopy(n): untyped =
   not c.isTemp(dest) and not fitsRegister(n.typ)
 
diff --git a/tests/vm/tvmmisc.nim b/tests/vm/tvmmisc.nim
index 6a8084647f..a178bb95eb 100644
--- a/tests/vm/tvmmisc.nim
+++ b/tests/vm/tvmmisc.nim
@@ -148,3 +148,32 @@ static:
 
   static:
     doAssert foo().i == 1
+
+# #10333
+block:
+  const
+    encoding: auto = [
+      ["", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"],
+      ["", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"],
+      ["", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"],
+      ["", "M", "MM", "MMM", "--", "-", "--", "---", "----", "--"],
+    ]
+  doAssert encoding.len == 4
+
+# #10886
+
+proc tor(): bool =
+  result = true
+  result = false or result
+
+proc tand(): bool =
+  result = false
+  result = true and result
+
+const
+  ctor = tor()
+  ctand = not tand()
+
+static:
+  doAssert ctor
+  doAssert ctand