Add test for #19641

Now that Bignum predicates are inlined (!6696), we only need to add a
test.

Fix #19641

3 files changed, 44 insertions, 0 deletions

diff --git a/testsuite/tests/numeric/should_compile/T19641.hs b/testsuite/tests/numeric/should_compile/T19641.hs
new file mode 100644
index 0000000000..826472d7a3
--- /dev/null
+++ b/testsuite/tests/numeric/should_compile/T19641.hs
@@ -0,0 +1,11 @@
+module Test where
+
+import Data.Bits
+import GHC.Num.Integer
+import GHC.Num.Natural
+
+integer_to_int :: Integer -> Maybe Int
+integer_to_int = toIntegralSized
+
+natural_to_word :: Natural -> Maybe Word
+natural_to_word = toIntegralSized
diff --git a/testsuite/tests/numeric/should_compile/T19641.stderr b/testsuite/tests/numeric/should_compile/T19641.stderr
new file mode 100644
index 0000000000..b79d0217ee
--- /dev/null
+++ b/testsuite/tests/numeric/should_compile/T19641.stderr
@@ -0,0 +1,32 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+  = {terms: 22, types: 20, coercions: 0, joins: 0/0}
+
+natural_to_word
+  = \ x ->
+      case x of {
+        NS x1 -> Just (W# x1);
+        NB ds -> Nothing
+      }
+
+integer_to_int
+  = \ x ->
+      case x of {
+        IS ipv -> Just (I# ipv);
+        IP x1 -> Nothing;
+        IN ds -> Nothing
+      }
+
+
+------ Local rules for imported ids --------
+"SPEC/Test toIntegralSized @Integer @Int"
+    forall $dIntegral $dIntegral1 $dBits $dBits1.
+      toIntegralSized $dIntegral $dIntegral1 $dBits $dBits1
+      = integer_to_int
+"SPEC/Test toIntegralSized @Natural @Word"
+    forall $dIntegral $dIntegral1 $dBits $dBits1.
+      toIntegralSized $dIntegral $dIntegral1 $dBits $dBits1
+      = natural_to_word
+
+
diff --git a/testsuite/tests/numeric/should_compile/all.T b/testsuite/tests/numeric/should_compile/all.T
index 087eb7b358..4bcccaa521 100644
--- a/testsuite/tests/numeric/should_compile/all.T
+++ b/testsuite/tests/numeric/should_compile/all.T
@@ -17,3 +17,4 @@ test('T20374', normal, compile, ['-ddump-simpl -O -dsuppress-all -dno-typeable-b
 test('T19769', normal, compile, ['-ddump-simpl -O -dsuppress-all -dno-typeable-binds -dsuppress-uniques'])
 test('T20347', normal, compile, ['-ddump-simpl -O -dsuppress-all -dno-typeable-binds -dsuppress-uniques'])
 test('T20448', normal, compile, ['-ddump-simpl -O -dsuppress-all -dno-typeable-binds -dsuppress-uniques'])
+test('T19641', normal, compile, ['-ddump-simpl -O -dsuppress-all -dno-typeable-binds -dsuppress-uniques'])