Re-do rubbish literals

As #19882 pointed out, we were simply doing rubbish literals wrong.
(I'll refrain from explaining the wrong-ness here -- see the ticket.)

This patch fixes it by adding a Type (of kind RuntimeRep) as field of
LitRubbish, rather than [PrimRep].

The Note [Rubbish literals] in GHC.Types.Literal explains the details.

4 files changed, 34 insertions, 13 deletions

diff --git a/testsuite/tests/stranal/should_compile/T18982.stderr b/testsuite/tests/stranal/should_compile/T18982.stderr
index 310eed5cc3..19f25be15c 100644
--- a/testsuite/tests/stranal/should_compile/T18982.stderr
+++ b/testsuite/tests/stranal/should_compile/T18982.stderr
@@ -1,6 +1,6 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 315, types: 214, coercions: 2, joins: 0/0}
+Result size of Tidy Core = {terms: 311, types: 214, coercions: 4, joins: 0/0}
 
 -- RHS size: {terms: 8, types: 9, coercions: 1, joins: 0/0}
 T18982.$WExGADT :: forall e. (e ~ Int) => e %1 -> Int %1 -> ExGADT Int
@@ -210,21 +210,21 @@ T18982.$tc'ExGADT2 = GHC.Types.TrNameS T18982.$tc'ExGADT3
 T18982.$tc'ExGADT :: GHC.Types.TyCon
 T18982.$tc'ExGADT = GHC.Types.TyCon 8468257409157161049## 5503123603717080600## T18982.$trModule T18982.$tc'ExGADT2 1# T18982.$tc'ExGADT1
 
--- RHS size: {terms: 13, types: 15, coercions: 0, joins: 0/0}
-T18982.$wi :: forall {a} {e}. e -> GHC.Prim.Int# -> GHC.Prim.Int#
-T18982.$wi = \ (@a) (@e) (ww :: e) (ww1 :: GHC.Prim.Int#) -> case RUBBISH[] @(a GHC.Prim.~# Int) of ww2 { __DEFAULT -> case ww of { __DEFAULT -> GHC.Prim.+# ww1 1# } }
+-- RHS size: {terms: 11, types: 10, coercions: 0, joins: 0/0}
+T18982.$wi :: forall {a} {e}. (a GHC.Prim.~# Int) -> e -> GHC.Prim.Int# -> GHC.Prim.Int#
+T18982.$wi = \ (@a) (@e) (ww :: a GHC.Prim.~# Int) (ww1 :: e) (ww2 :: GHC.Prim.Int#) -> case ww1 of { __DEFAULT -> GHC.Prim.+# ww2 1# }
 
--- RHS size: {terms: 15, types: 22, coercions: 0, joins: 0/0}
+-- RHS size: {terms: 15, types: 22, coercions: 1, joins: 0/0}
 i :: forall a. ExGADT a -> Int
-i = \ (@a) (w :: ExGADT a) -> case w of { ExGADT @e ww1 ww2 ww3 ww4 -> case ww4 of { GHC.Types.I# ww6 -> case T18982.$wi @a @e ww3 ww6 of ww7 { __DEFAULT -> GHC.Types.I# ww7 } } }
+i = \ (@a) (w :: ExGADT a) -> case w of { ExGADT @e ww ww1 ww2 ww3 -> case ww3 of { GHC.Types.I# ww4 -> case T18982.$wi @a @e @~(ww :: a GHC.Prim.~# Int) ww2 ww4 of ww5 { __DEFAULT -> GHC.Types.I# ww5 } } }
 
--- RHS size: {terms: 8, types: 12, coercions: 0, joins: 0/0}
-T18982.$wh :: forall {a}. GHC.Prim.Int# -> GHC.Prim.Int#
-T18982.$wh = \ (@a) (ww :: GHC.Prim.Int#) -> case RUBBISH[] @(a GHC.Prim.~# Int) of ww1 { __DEFAULT -> GHC.Prim.+# ww 1# }
+-- RHS size: {terms: 6, types: 7, coercions: 0, joins: 0/0}
+T18982.$wh :: forall {a}. (a GHC.Prim.~# Int) -> GHC.Prim.Int# -> GHC.Prim.Int#
+T18982.$wh = \ (@a) (ww :: a GHC.Prim.~# Int) (ww1 :: GHC.Prim.Int#) -> GHC.Prim.+# ww1 1#
 
--- RHS size: {terms: 14, types: 15, coercions: 0, joins: 0/0}
+-- RHS size: {terms: 14, types: 15, coercions: 1, joins: 0/0}
 h :: forall a. GADT a -> Int
-h = \ (@a) (w :: GADT a) -> case w of { GADT ww1 ww2 -> case ww2 of { GHC.Types.I# ww4 -> case T18982.$wh @a ww4 of ww5 { __DEFAULT -> GHC.Types.I# ww5 } } }
+h = \ (@a) (w :: GADT a) -> case w of { GADT ww ww1 -> case ww1 of { GHC.Types.I# ww2 -> case T18982.$wh @a @~(ww :: a GHC.Prim.~# Int) ww2 of ww3 { __DEFAULT -> GHC.Types.I# ww3 } } }
 
 -- RHS size: {terms: 9, types: 4, coercions: 0, joins: 0/0}
 T18982.$wg :: forall {e}. e -> GHC.Prim.Int# -> GHC.Prim.Int#
@@ -232,7 +232,7 @@ T18982.$wg = \ (@e) (ww :: e) (ww1 :: GHC.Prim.Int#) -> case ww of { __DEFAULT -
 
 -- RHS size: {terms: 14, types: 11, coercions: 0, joins: 0/0}
 g :: Ex Int -> Int
-g = \ (w :: Ex Int) -> case w of { Ex @e ww1 ww2 -> case ww2 of { GHC.Types.I# ww4 -> case T18982.$wg @e ww1 ww4 of ww5 { __DEFAULT -> GHC.Types.I# ww5 } } }
+g = \ (w :: Ex Int) -> case w of { Ex @e ww ww1 -> case ww1 of { GHC.Types.I# ww2 -> case T18982.$wg @e ww ww2 of ww3 { __DEFAULT -> GHC.Types.I# ww3 } } }
 
 -- RHS size: {terms: 4, types: 1, coercions: 0, joins: 0/0}
 T18982.$wf :: GHC.Prim.Int# -> GHC.Prim.Int#
@@ -240,7 +240,7 @@ T18982.$wf = \ (ww :: GHC.Prim.Int#) -> GHC.Prim.+# ww 1#
 
 -- RHS size: {terms: 13, types: 8, coercions: 0, joins: 0/0}
 f :: Box Int -> Int
-f = \ (w :: Box Int) -> case w of { Box ww1 -> case ww1 of { GHC.Types.I# ww3 -> case T18982.$wf ww3 of ww4 { __DEFAULT -> GHC.Types.I# ww4 } } }
+f = \ (w :: Box Int) -> case w of { Box ww -> case ww of { GHC.Types.I# ww1 -> case T18982.$wf ww1 of ww2 { __DEFAULT -> GHC.Types.I# ww2 } } }
 
 
 
diff --git a/testsuite/tests/stranal/should_compile/T19882a.hs b/testsuite/tests/stranal/should_compile/T19882a.hs
new file mode 100644
index 0000000000..65d920dfc9
--- /dev/null
+++ b/testsuite/tests/stranal/should_compile/T19882a.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE UnboxedTuples, MagicHash #-}
+
+module T19882a where
+
+import GHC.Exts
+
+f1 :: (# State# RealWorld, Int, Int #) -> Bool -> Int
+f1 x True  = 1
+f1 x False = f1 x True
+
diff --git a/testsuite/tests/stranal/should_compile/T19882b.hs b/testsuite/tests/stranal/should_compile/T19882b.hs
new file mode 100644
index 0000000000..455bd016c1
--- /dev/null
+++ b/testsuite/tests/stranal/should_compile/T19882b.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE UnboxedTuples, MagicHash #-}
+
+module T19882b where
+
+import GHC.Exts
+
+f2 :: (# State# RealWorld, Int #) -> Bool -> Int
+f2 x True  = 1
+f2 x False = f2 x True
diff --git a/testsuite/tests/stranal/should_compile/all.T b/testsuite/tests/stranal/should_compile/all.T
index 61e9c58dee..f5ebbf289a 100644
--- a/testsuite/tests/stranal/should_compile/all.T
+++ b/testsuite/tests/stranal/should_compile/all.T
@@ -67,3 +67,5 @@ test('T18982',  [ grep_errmsg(r'\$w. .*Int#$') ], compile, ['-dppr-cols=1000 -dd
 
 test('T19180', normal, compile, [''])
 test('T19849', normal, compile, [''])
+test('T19882a', normal, compile, [''])
+test('T19882b', normal, compile, [''])