gmpints: increase test coverage

Specifically, add tests designed to trigger the ObjInt_UIntInv call inside of GMPorINTOBJ_FAKEMPZ.
gap-system · Jan 16, 2017 · 3549c0b · 3549c0b
1 parent 08da809
commit 3549c0b
Showing 1 changed file with 12 additions and 0 deletions.
diff --git a/tst/testinstall/intarith.tst b/tst/testinstall/intarith.tst
@@ -122,6 +122,18 @@ gap> List(data, x -> bigPos - x);
 gap> ForAll(data, x -> ForAll(data, y -> (x-y) = -(y-x)));
 true
 
+# verify corner case in GMPorINTOBJ_FAKEMPZ in ObjInt_UIntInv:
+# difference of two large gmps is small, but not quite small enough for
+# an immediate
+gap> 2^100 - (2^100 + 2^60);
+-1152921504606846976
+gap> 2^100 - (2^100 + 2^62);
+-4611686018427387904
+gap> 2^100 - (2^100 + 2^28);
+-268435456
+gap> 2^100 - (2^100 + 2^30);
+-1073741824
+
 #
 # ProdInt
 #