diff --git a/compiler/ccgreset.nim b/compiler/ccgreset.nim
index bd0e2a58a3..47b6a1e15e 100644
--- a/compiler/ccgreset.nim
+++ b/compiler/ccgreset.nim
@@ -95,11 +95,11 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
       lineCg(p, cpsStmts, "$1 = 0;$n", [accessor])
     else:
       raiseAssert "unexpected set type kind"
-  of {tyNone, tyEmpty, tyNil, tyUntyped, tyTyped, tyGenericInvocation,
+  of tyNone, tyEmpty, tyNil, tyUntyped, tyTyped, tyGenericInvocation,
       tyGenericParam, tyOrdinal, tyRange, tyOpenArray, tyForward, tyVarargs,
       tyUncheckedArray, tyProxy, tyBuiltInTypeClass, tyUserTypeClass,
       tyUserTypeClassInst, tyCompositeTypeClass, tyAnd, tyOr, tyNot,
-      tyAnything, tyStatic, tyFromExpr, tyConcept, tyVoid, tyIterable}:
+      tyAnything, tyStatic, tyFromExpr, tyConcept, tyVoid, tyIterable:
     discard
 
 proc specializeReset(p: BProc, a: TLoc) =
diff --git a/compiler/nir/ast2ir.nim b/compiler/nir/ast2ir.nim
new file mode 100644
index 0000000000..0fa145264f
--- /dev/null
+++ b/compiler/nir/ast2ir.nim
@@ -0,0 +1,37 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+import std / [assertions, tables]
+import ".." / [ast, types, options, lineinfos, msgs]
+import .. / ic / bitabs
+
+import nirtypes, nirinsts, nirlineinfos
+
+type
+  Context = object
+    conf: ConfigRef
+    lastFileKey: FileIndex
+    lastFileVal: LitId
+    strings: BiTable[string]
+    man: LineInfoManager
+
+proc toLineInfo(i: TLineInfo; c: var Context): PackedLineInfo =
+  var val: LitId
+  if c.lastFileKey == i.fileIndex:
+    val = c.lastFileVal
+  else:
+    val = c.strings.getOrIncl(toFullPath(c.conf, i.fileIndex))
+    # remember the entry:
+    c.lastFileKey = i.fileIndex
+    c.lastFileVal = val
+  result = pack(c.man, val, int32 i.line, int32 i.col)
+
+proc astToIr*(n: PNode; dest: var Tree; c: var Context) =
+  let info = toLineInfo(n.info, c)
+
diff --git a/compiler/nir/cir.nim b/compiler/nir/cir.nim
index 6a1d9d9b36..90a3035ddb 100644
--- a/compiler/nir/cir.nim
+++ b/compiler/nir/cir.nim
@@ -1,78 +1,78 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2023 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-# We produce C code as a list of tokens.
-
-import std / assertions
-import .. / ic / bitabs
-
-type
-  Token = LitId # indexing into the tokens BiTable[string]
-
-  PredefinedToken = enum
-    IgnoreMe = "<unused>"
-    EmptyToken = ""
-    DeclPrefix = "" # the next token is the name of a definition
-    CurlyLe = "{"
-    CurlyRi = "}"
-    ParLe = "("
-    ParRi = ")"
-    BracketLe = "["
-    BracketRi = "]"
-    NewLine = "\n"
-    Semicolon = ";"
-    Comma = ", "
-    Space = " "
-    Colon = ":"
-    Dot = "."
-    Arrow = "->"
-    Star = "*"
-    Amp = "&"
-    AsgnOpr = " = "
-    ScopeOpr = "::"
-    ConstKeyword = "const "
-    StaticKeyword = "static "
-    NimString = "NimString"
-    StrLitPrefix = "(NimChar*)"
-    StrLitNamePrefix = "Qstr"
-    LoopKeyword = "while (true) "
-    WhileKeyword = "while ("
-    IfKeyword = "if ("
-    ElseKeyword = "else "
-    SwitchKeyword = "switch ("
-    CaseKeyword = "case "
-    DefaultKeyword = "default:"
-    BreakKeyword = "break"
-    NullPtr = "nullptr"
-    IfNot = "if (!("
-    ReturnKeyword = "return "
-
-const
-  ModulePrefix = Token(int(ReturnKeyword)+1)
-
-proc fillTokenTable(tab: var BiTable[string]) =
-  for e in EmptyToken..high(PredefinedToken):
-    let id = tab.getOrIncl $e
-    assert id == LitId(e)
-
-type
-  GeneratedCode* = object
-    code: seq[LitId]
-    tokens: BiTable[string]
-
-proc initGeneratedCode*(): GeneratedCode =
-  result = GeneratedCode(code: @[], tokens: initBiTable[string]())
-  fillTokenTable(result.tokens)
-
-proc add*(g: var GeneratedCode; t: PredefinedToken) {.inline.} =
-  g.code.add Token(t)
-
-proc add*(g: var GeneratedCode; s: string) {.inline.} =
-  g.code.add g.tokens.getOrIncl(s)
-
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# We produce C code as a list of tokens.
+
+import std / assertions
+import .. / ic / bitabs
+
+type
+  Token = LitId # indexing into the tokens BiTable[string]
+
+  PredefinedToken = enum
+    IgnoreMe = "<unused>"
+    EmptyToken = ""
+    DeclPrefix = "" # the next token is the name of a definition
+    CurlyLe = "{"
+    CurlyRi = "}"
+    ParLe = "("
+    ParRi = ")"
+    BracketLe = "["
+    BracketRi = "]"
+    NewLine = "\n"
+    Semicolon = ";"
+    Comma = ", "
+    Space = " "
+    Colon = ":"
+    Dot = "."
+    Arrow = "->"
+    Star = "*"
+    Amp = "&"
+    AsgnOpr = " = "
+    ScopeOpr = "::"
+    ConstKeyword = "const "
+    StaticKeyword = "static "
+    NimString = "NimString"
+    StrLitPrefix = "(NimChar*)"
+    StrLitNamePrefix = "Qstr"
+    LoopKeyword = "while (true) "
+    WhileKeyword = "while ("
+    IfKeyword = "if ("
+    ElseKeyword = "else "
+    SwitchKeyword = "switch ("
+    CaseKeyword = "case "
+    DefaultKeyword = "default:"
+    BreakKeyword = "break"
+    NullPtr = "nullptr"
+    IfNot = "if (!("
+    ReturnKeyword = "return "
+
+const
+  ModulePrefix = Token(int(ReturnKeyword)+1)
+
+proc fillTokenTable(tab: var BiTable[string]) =
+  for e in EmptyToken..high(PredefinedToken):
+    let id = tab.getOrIncl $e
+    assert id == LitId(e)
+
+type
+  GeneratedCode* = object
+    code: seq[LitId]
+    tokens: BiTable[string]
+
+proc initGeneratedCode*(): GeneratedCode =
+  result = GeneratedCode(code: @[], tokens: initBiTable[string]())
+  fillTokenTable(result.tokens)
+
+proc add*(g: var GeneratedCode; t: PredefinedToken) {.inline.} =
+  g.code.add Token(t)
+
+proc add*(g: var GeneratedCode; s: string) {.inline.} =
+  g.code.add g.tokens.getOrIncl(s)
+
diff --git a/compiler/nir/nirinsts.nim b/compiler/nir/nirinsts.nim
index e285d6efb5..e12973c450 100644
--- a/compiler/nir/nirinsts.nim
+++ b/compiler/nir/nirinsts.nim
@@ -68,6 +68,10 @@ type
     Eq,
     Le,
     Lt,
+    Cast,
+    NumberConv,
+    CheckedObjConv,
+    ObjConv,
     Emit,
     ProcDecl
 
diff --git a/compiler/nir/nirtypes.nim b/compiler/nir/nirtypes.nim
index c3e2e4db01..aef5264c70 100644
--- a/compiler/nir/nirtypes.nim
+++ b/compiler/nir/nirtypes.nim
@@ -176,6 +176,10 @@ proc nominalType*(tree: var TypeGraph; kind: NirTypeKind; name: string): TypeId
   result = TypeId tree.nodes.len
   tree.nodes.add TypeNode(x: toX(kind, tree.names.getOrIncl(name)))
 
+proc getFloat128Type*(tree: var TypeGraph): TypeId =
+  result = TypeId tree.nodes.len
+  tree.nodes.add TypeNode(x: toX(FloatTy, 128'u32))
+
 proc addBuiltinType*(g: var TypeGraph; id: TypeId) =
   g.nodes.add g[id]
 
diff --git a/compiler/nir/types2ir.nim b/compiler/nir/types2ir.nim
new file mode 100644
index 0000000000..55593682be
--- /dev/null
+++ b/compiler/nir/types2ir.nim
@@ -0,0 +1,237 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+import std / [assertions, tables]
+import ".." / [ast, types, options]
+import nirtypes
+
+type
+  Context = object
+    processed: Table[ItemId, TypeId]
+    g: TypeGraph
+    conf: ConfigRef
+
+template cached(c: var Context; t: PType; body: untyped) =
+  result = c.processed.getOrDefault(t.itemId)
+  if result.int == 0:
+    body
+    c.processed[t.itemId] = result
+
+proc typeToIr*(c: var Context; t: PType): TypeId
+
+proc collectFieldTypes(c: var Context; n: PNode; dest: var seq[TypeId]) =
+  case n.kind
+  of nkRecList:
+    for i in 0..<n.len:
+      collectFieldTypes(c, n[i], dest)
+  of nkRecCase:
+    assert(n[0].kind == nkSym)
+    collectFieldTypes(c, n[0], dest)
+    for i in 1..<n.len:
+      case n[i].kind
+      of nkOfBranch, nkElse:
+        collectFieldTypes c, lastSon(n[i]), dest
+      else: discard
+  of nkSym:
+    assert n.sym.position == dest.len
+    dest.add typeToIr(c, n.sym.typ)
+  else:
+    assert false, "unknown node kind: " & $n.kind
+
+proc objectToIr(c: var Context; n: PNode; fieldTypes: seq[TypeId]; unionId: var int) =
+  case n.kind
+  of nkRecList:
+    for i in 0..<n.len:
+      objectToIr(c, n[i], fieldTypes, unionId)
+  of nkRecCase:
+    assert(n[0].kind == nkSym)
+    objectToIr(c, n[0], fieldTypes, unionId)
+    let u = openType(c.g, UnionDecl)
+    c.g.addName "u_" & $unionId
+    inc unionId
+    for i in 1..<n.len:
+      case n[i].kind
+      of nkOfBranch, nkElse:
+        let subObj = openType(c.g, ObjectDecl)
+        c.g.addName "uo_" & $unionId & "_" & $i
+        objectToIr c, lastSon(n[i]), fieldTypes, unionId
+        discard sealType(c.g, subObj)
+      else: discard
+    discard sealType(c.g, u)
+  of nkSym:
+    c.g.addField n.sym.name.s & "_" & $n.sym.position, fieldTypes[n.sym.position]
+  else:
+    assert false, "unknown node kind: " & $n.kind
+
+proc objectToIr(c: var Context; t: PType): TypeId =
+  var unionId = 0
+  var fieldTypes: seq[TypeId] = @[]
+  collectFieldTypes c, t.n, fieldTypes
+  let obj = openType(c.g, ObjectDecl)
+  # XXX Proper name mangling here!
+  c.g.addName t.sym.name.s
+  objectToIr c, t.n, fieldTypes, unionId
+  result = sealType(c.g, obj)
+
+proc tupleToIr(c: var Context; t: PType): TypeId =
+  var fieldTypes = newSeq[TypeId](t.len)
+  for i in 0..<t.len:
+    fieldTypes[i] = typeToIr(c, t[i])
+  let obj = openType(c.g, ObjectDecl)
+  # XXX Proper name mangling here!
+  c.g.addName "tupleX"
+  for i in 0..<t.len:
+    c.g.addField "f_" & $i, fieldTypes[i]
+  result = sealType(c.g, obj)
+
+proc procToIr(c: var Context; t: PType): TypeId =
+  var fieldTypes = newSeq[TypeId](t.len)
+  for i in 0..<t.len:
+    fieldTypes[i] = typeToIr(c, t[i])
+  let obj = openType(c.g, ProcTy)
+  # XXX Add Calling convention here!
+  for i in 0..<t.len:
+    c.g.addType fieldTypes[i]
+  result = sealType(c.g, obj)
+
+proc typeToIr*(c: var Context; t: PType): TypeId =
+  case t.kind
+  of tyInt:
+    case int(getSize(c.conf, t))
+    of 2: result = Int16Id
+    of 4: result = Int32Id
+    else: result = Int64Id
+  of tyInt8: result = Int8Id
+  of tyInt16: result = Int16Id
+  of tyInt32: result = Int32Id
+  of tyInt64: result = Int64Id
+  of tyFloat:
+    case int(getSize(c.conf, t))
+    of 4: result = Float32Id
+    else: result = Float64Id
+  of tyFloat32: result = Float32Id
+  of tyFloat64: result = Float64Id
+  of tyFloat128: result = getFloat128Type(c.g)
+  of tyUInt:
+    case int(getSize(c.conf, t))
+    of 2: result = UInt16Id
+    of 4: result = UInt32Id
+    else: result = UInt64Id
+  of tyUInt8: result = UInt8Id
+  of tyUInt16: result = UInt16Id
+  of tyUInt32: result = UInt32Id
+  of tyUInt64: result = UInt64Id
+  of tyBool: result = Bool8Id
+  of tyChar: result = Char8Id
+  of tyVoid: result = VoidId
+  of tySink, tyGenericInst, tyDistinct, tyAlias, tyOwned, tyRange:
+    result = typeToIr(c, t.lastSon)
+  of tyEnum:
+    if firstOrd(c.conf, t) < 0:
+      result = Int32Id
+    else:
+      case int(getSize(c.conf, t))
+      of 1: result = UInt8Id
+      of 2: result = UInt16Id
+      of 4: result = Int32Id
+      of 8: result = Int64Id
+      else: result = Int32Id
+  of tyOrdinal, tyGenericBody, tyGenericParam, tyInferred, tyStatic:
+    if t.len > 0:
+      result = typeToIr(c, t.lastSon)
+    else:
+      result = TypeId(-1)
+  of tyFromExpr:
+    if t.n != nil and t.n.typ != nil:
+      result = typeToIr(c, t.n.typ)
+    else:
+      result = TypeId(-1)
+  of tyArray:
+    cached(c, t):
+      var n = toInt64(lengthOrd(c.conf, t))
+      if n <= 0: n = 1   # make an array of at least one element
+      let elemType = typeToIr(c, t[1])
+      let a = openType(c.g, ArrayTy)
+      c.g.addType(elemType)
+      c.g.addArrayLen uint64(n)
+      result = sealType(c.g, a)
+  of tyPtr, tyRef:
+    cached(c, t):
+      let e = t.lastSon
+      if e.kind == tyUncheckedArray:
+        let elemType = typeToIr(c, e.lastSon)
+        let a = openType(c.g, AArrayPtrTy)
+        c.g.addType(elemType)
+        result = sealType(c.g, a)
+      else:
+        let elemType = typeToIr(c, t.lastSon)
+        let a = openType(c.g, APtrTy)
+        c.g.addType(elemType)
+        result = sealType(c.g, a)
+  of tyVar, tyLent:
+    cached(c, t):
+      let elemType = typeToIr(c, t.lastSon)
+      let a = openType(c.g, APtrTy)
+      c.g.addType(elemType)
+      result = sealType(c.g, a)
+  of tySet:
+    let s = int(getSize(c.conf, t))
+    case s
+    of 1: result = UInt8Id
+    of 2: result = UInt16Id
+    of 4: result = UInt32Id
+    of 8: result = UInt64Id
+    else:
+      # array[U8, s]
+      cached(c, t):
+        let a = openType(c.g, ArrayTy)
+        c.g.addType(UInt8Id)
+        c.g.addArrayLen uint64(s)
+        result = sealType(c.g, a)
+  of tyPointer:
+    let a = openType(c.g, APtrTy)
+    c.g.addBuiltinType(VoidId)
+    result = sealType(c.g, a)
+  of tyObject:
+    cached(c, t):
+      result = objectToIr(c, t)
+  of tyTuple:
+    cached(c, t):
+      result = tupleToIr(c, t)
+  of tyProc:
+    cached(c, t):
+      result = procToIr(c, t)
+  of tyVarargs, tyOpenArray:
+    cached(c, t):
+      # object (a: ArrayPtr[T], len: int)
+      result = TypeId(-1)
+  of tyString:
+    cached(c, t):
+      # a string a pair of `len, p` with convoluted `p`:
+      result = TypeId(-1)
+  of tySequence:
+    cached(c, t):
+      result = TypeId(-1)
+  of tyCstring:
+    cached(c, t):
+      let a = openType(c.g, AArrayPtrTy)
+      c.g.addBuiltinType Char8Id
+      result = sealType(c.g, a)
+  of tyUncheckedArray:
+    # We already handled the `ptr UncheckedArray` in a special way.
+    cached(c, t):
+      let elemType = typeToIr(c, t.lastSon)
+      let a = openType(c.g, LastArrayTy)
+      c.g.addType(elemType)
+      result = sealType(c.g, a)
+  of tyNone, tyEmpty, tyUntyped, tyTyped, tyTypeDesc,
+     tyNil, tyGenericInvocation, tyProxy, tyBuiltInTypeClass,
+     tyUserTypeClass, tyUserTypeClassInst, tyCompositeTypeClass,
+     tyAnd, tyOr, tyNot, tyAnything, tyConcept, tyIterable, tyForward:
+    result = TypeId(-1)