stuff

1 files changed, 47 insertions, 0 deletions

diff --git a/src/type.cff b/src/type.cff
index 33d78e6..97fc44a 100644
--- a/src/type.cff
+++ b/src/type.cff
@@ -136,3 +136,50 @@ extern fn putprimtypes(env *Env) void {
    )
    ty_voidptr = interntype({ .size: g_targ.ptrsize, .u: :Ptr ty_void });
 }
+
+extern fn isnumtype(ty *const Type) bool {
+   return ty->is(:Int) or ty->is(:Flo);
+}
+
+fn numtype2rank(ty *const Type) int {
+   ty = unconstify(ty);
+   switch {
+   case ty->is(:Int) and (ty == ty_int or ty.size < ty_int.size);
+      return 0;
+   case ty == ty_uint; return 1;
+   case ty == ty_i32;  return 2;
+   case ty == ty_u32;  return 3;
+   case ty == ty_i64;  return 4;
+   case ty == ty_u64;  return 5;
+   case ty == ty_f32;  return 6;
+   case ty == ty_f64;  return 7;
+   }
+   return -1;
+}
+
+fn rank2numtype(r int) *const Type {
+   static const types []**const Type = {
+      &ty_int, &ty_uint, &ty_i32, &ty_u32,
+      &ty_i64, &ty_u64, &ty_f32, &ty_f64,
+   };
+   assert(r >= 0 and r < types.#len, "rank");
+   return *types[r];
+}
+
+extern fn typeof2(a *const Type, b *const Type) *const Type {
+   if a == b and not a->is(:Int) {
+      return a;
+   }
+   if isnumtype(a) and isnumtype(b) {
+      let ra = numtype2rank(a),
+          rb = numtype2rank(b);
+      return rank2numtype(MAX(ra, rb));
+   }
+   if unconstify(a) == b {
+      return a;
+   }
+   if a == unconstify(b) {
+      return b;
+   }
+   return #null;
+}