fixes #25254; fixes #10395; Invalid pred in when swallowed (#25385)

fixes #25254
fixes #10395

compiler/vm.nim

@@ -1723,6 +1723,12 @@ proc rawExecute(c: PCtx, start: int, tos: PStackFrame): TFullReg =
       let max = (1.BiggestInt shl (rb-1))-1
       if regs[ra].intVal < min or regs[ra].intVal > max:
         stackTrace(c, tos, pc, "unhandled exception: value out of range")
+    of opcNarrowR:
+      decodeBC(rkInt)
+      let min = regs[rb].intVal
+      let max = regs[rc].intVal
+      if regs[ra].intVal < min or regs[ra].intVal > max:
+        stackTrace(c, tos, pc, "unhandled exception: value out of range")
     of opcNarrowU:
       decodeB(rkInt)
       regs[ra].intVal = regs[ra].intVal and ((1'i64 shl rb)-1)

compiler/vmdef.nim

@@ -105,7 +105,7 @@ type
     opcIsNil, opcOf, opcIs,
     opcParseFloat, opcConv, opcCast,
     opcQuit, opcInvalidField,
-    opcNarrowS, opcNarrowU,
+    opcNarrowS, opcNarrowU, opcNarrowR
     opcSignExtend,
 
     opcAddStrCh,

compiler/vmgen.nim

@@ -798,6 +798,11 @@ proc genNarrow(c: PCtx; n: PNode; dest: TDest) =
     c.gABC(n, opcNarrowU, dest, TRegister(size*8))
   elif t.kind in {tyInt8..tyInt32} or (t.kind == tyInt and size < 8):
     c.gABC(n, opcNarrowS, dest, TRegister(size*8))
+  elif t.kind in {tyEnum, tyRange}:
+    let intType = getSysType(c.graph, n.info, tyInt)
+    let first = c.genx(newIntTypeNode(firstOrd(c.config, t), intType))
+    let last = c.genx(newIntTypeNode(lastOrd(c.config, t), intType))
+    c.gABC(n, opcNarrowR, dest, first, last)
 
 proc genNarrowU(c: PCtx; n: PNode; dest: TDest) =
   let t = skipTypes(n.typ, abstractVar-{tyTypeDesc})

tests/errmsgs/tvmranges.nim

@@ -0,0 +1,17 @@
+discard """
+  action: reject
+  nimout: '''
+stack trace: (most recent call last)
+tvmranges.nim(14, 10)
+tvmranges.nim(14, 10) Error: unhandled exception: value out of range
+'''
+"""
+
+type X = enum
+  a
+  b
+
+when pred(a) == b:
+  echo "a"
+else:
+  echo "b"