Merge remote-tracking branch 'origin/master' into wip/impredicativity

Conflicts:
	compiler/typecheck/Inst.hs
	compiler/typecheck/TcBinds.hs
	compiler/typecheck/TcExpr.hs
	compiler/typecheck/TcRnTypes.hs
	compiler/types/Unify.hs

13 files changed, 53 insertions, 0 deletions

diff --git a/testsuite/tests/simplCore/should_compile/Makefile b/testsuite/tests/simplCore/should_compile/Makefile
index a7460b0d14..7f43dafdc8 100644
--- a/testsuite/tests/simplCore/should_compile/Makefile
+++ b/testsuite/tests/simplCore/should_compile/Makefile
@@ -126,3 +126,9 @@ T8221:
 T5996:
 	$(RM) -f T5996.o T5996.hi
 	'$(TEST_HC)' $(TEST_HC_OPTS) -O -c T5996.hs -ddump-simpl -dsuppress-uniques -dsuppress-all | grep y2
+
+T10083:
+	$(RM) -f T10083.o T10083.hi T10083.hi-boot T10083a.o T10083a.hi 
+	'$(TEST_HC)' $(TEST_HC_OPTS) -c -O T10083.hs-boot
+	'$(TEST_HC)' $(TEST_HC_OPTS) -c -O T10083a.hs
+	'$(TEST_HC)' $(TEST_HC_OPTS) -c -O T10083.hs
diff --git a/testsuite/tests/simplCore/should_compile/T10083.hs b/testsuite/tests/simplCore/should_compile/T10083.hs
new file mode 100644
index 0000000000..df896e6dab
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T10083.hs
@@ -0,0 +1,5 @@
+module T10083 where
+  import T10083a
+  data RSR = MkRSR SR
+  eqRSR (MkRSR s1) (MkRSR s2) = (eqSR s1 s2)
+  foo x y = not (eqRSR x y)
diff --git a/testsuite/tests/simplCore/should_compile/T10083.hs-boot b/testsuite/tests/simplCore/should_compile/T10083.hs-boot
new file mode 100644
index 0000000000..3d3e4a1281
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T10083.hs-boot
@@ -0,0 +1,3 @@
+module T10083 where
+  data RSR
+  eqRSR :: RSR -> RSR -> Bool
diff --git a/testsuite/tests/simplCore/should_compile/T10083a.hs b/testsuite/tests/simplCore/should_compile/T10083a.hs
new file mode 100644
index 0000000000..f4fd782a99
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T10083a.hs
@@ -0,0 +1,4 @@
+module T10083a where
+  import {-# SOURCE #-} T10083
+  data SR = MkSR RSR
+  eqSR (MkSR r1) (MkSR r2) = eqRSR r1 r2
diff --git a/testsuite/tests/simplCore/should_compile/T10181.hs b/testsuite/tests/simplCore/should_compile/T10181.hs
new file mode 100644
index 0000000000..1983507cd2
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T10181.hs
@@ -0,0 +1,3 @@
+module T10181 where
+
+t a = t a
diff --git a/testsuite/tests/simplCore/should_compile/T3717.stderr b/testsuite/tests/simplCore/should_compile/T3717.stderr
index 9515266807..374533605e 100644
--- a/testsuite/tests/simplCore/should_compile/T3717.stderr
+++ b/testsuite/tests/simplCore/should_compile/T3717.stderr
@@ -3,6 +3,7 @@
 Result size of Tidy Core = {terms: 22, types: 10, coercions: 0}
 
 Rec {
+-- RHS size: {terms: 10, types: 2, coercions: 0}
 T3717.$wfoo [InlPrag=[0], Occ=LoopBreaker] :: Int# -> Int#
 [GblId, Arity=1, Caf=NoCafRefs, Str=DmdType <S,1*U>]
 T3717.$wfoo =
@@ -13,6 +14,7 @@ T3717.$wfoo =
     }
 end Rec }
 
+-- RHS size: {terms: 10, types: 4, coercions: 0}
 foo [InlPrag=INLINE[0]] :: Int -> Int
 [GblId,
  Arity=1,
diff --git a/testsuite/tests/simplCore/should_compile/T3772.stdout b/testsuite/tests/simplCore/should_compile/T3772.stdout
index 3d236823a6..e74fa39cb5 100644
--- a/testsuite/tests/simplCore/should_compile/T3772.stdout
+++ b/testsuite/tests/simplCore/should_compile/T3772.stdout
@@ -3,6 +3,7 @@
 Result size of Tidy Core = {terms: 26, types: 11, coercions: 0}
 
 Rec {
+-- RHS size: {terms: 10, types: 2, coercions: 0}
 $wxs :: Int# -> ()
 [GblId, Arity=1, Caf=NoCafRefs, Str=DmdType <S,1*U>]
 $wxs =
@@ -13,6 +14,7 @@ $wxs =
     }
 end Rec }
 
+-- RHS size: {terms: 14, types: 5, coercions: 0}
 foo [InlPrag=NOINLINE] :: Int -> ()
 [GblId, Arity=1, Caf=NoCafRefs, Str=DmdType <S,1*U(U)>]
 foo =
diff --git a/testsuite/tests/simplCore/should_compile/T4908.stderr b/testsuite/tests/simplCore/should_compile/T4908.stderr
index ee3418c5bf..6ad89470bb 100644
--- a/testsuite/tests/simplCore/should_compile/T4908.stderr
+++ b/testsuite/tests/simplCore/should_compile/T4908.stderr
@@ -3,6 +3,7 @@
 Result size of Tidy Core = {terms: 54, types: 38, coercions: 0}
 
 Rec {
+-- RHS size: {terms: 19, types: 5, coercions: 0}
 T4908.f_$s$wf [Occ=LoopBreaker] :: Int# -> Int -> Int# -> Bool
 [GblId, Arity=3, Caf=NoCafRefs, Str=DmdType <S,1*U><L,A><L,U>]
 T4908.f_$s$wf =
@@ -17,6 +18,7 @@ T4908.f_$s$wf =
     }
 end Rec }
 
+-- RHS size: {terms: 24, types: 13, coercions: 0}
 T4908.$wf [InlPrag=[0]] :: Int# -> (Int, Int) -> Bool
 [GblId,
  Arity=2,
@@ -39,6 +41,7 @@ T4908.$wf =
       0# -> True
     }
 
+-- RHS size: {terms: 8, types: 6, coercions: 0}
 f [InlPrag=INLINE[0]] :: Int -> (Int, Int) -> Bool
 [GblId,
  Arity=2,
diff --git a/testsuite/tests/simplCore/should_compile/T4930.stderr b/testsuite/tests/simplCore/should_compile/T4930.stderr
index faf513477d..3e140ddc92 100644
--- a/testsuite/tests/simplCore/should_compile/T4930.stderr
+++ b/testsuite/tests/simplCore/should_compile/T4930.stderr
@@ -2,14 +2,17 @@
 ==================== Tidy Core ====================
 Result size of Tidy Core = {terms: 23, types: 11, coercions: 0}
 
+-- RHS size: {terms: 2, types: 0, coercions: 0}
 lvl :: [Char]
 [GblId, Str=DmdType]
 lvl = unpackCString# "Too small"#
 
+-- RHS size: {terms: 2, types: 1, coercions: 0}
 T4930.foo1 :: Int
 [GblId, Str=DmdType b]
 T4930.foo1 = error @ Int lvl
 
+-- RHS size: {terms: 16, types: 5, coercions: 0}
 foo :: Int -> Int
 [GblId,
  Arity=1,
diff --git a/testsuite/tests/simplCore/should_compile/T7360.stderr b/testsuite/tests/simplCore/should_compile/T7360.stderr
index ec3c4b08fb..f7979075ac 100644
--- a/testsuite/tests/simplCore/should_compile/T7360.stderr
+++ b/testsuite/tests/simplCore/should_compile/T7360.stderr
@@ -2,6 +2,7 @@
 ==================== Tidy Core ====================
 Result size of Tidy Core = {terms: 36, types: 29, coercions: 0}
 
+-- RHS size: {terms: 6, types: 3, coercions: 0}
 T7360.$WFoo3 [InlPrag=INLINE] :: Int -> Foo
 [GblId[DataConWrapper],
  Arity=1,
@@ -16,10 +17,12 @@ T7360.$WFoo3 =
   \ (dt [Occ=Once!] :: Int) ->
     case dt of _ [Occ=Dead] { I# dt [Occ=Once] -> T7360.Foo3 dt }
 
+-- RHS size: {terms: 5, types: 2, coercions: 0}
 fun1 [InlPrag=NOINLINE] :: Foo -> ()
 [GblId, Arity=1, Caf=NoCafRefs, Str=DmdType <S,1*U>]
 fun1 = \ (x :: Foo) -> case x of _ [Occ=Dead] { __DEFAULT -> () }
 
+-- RHS size: {terms: 2, types: 0, coercions: 0}
 T7360.fun5 :: ()
 [GblId,
  Str=DmdType,
@@ -27,6 +30,7 @@ T7360.fun5 :: ()
          WorkFree=False, Expandable=False, Guidance=IF_ARGS [] 20 0}]
 T7360.fun5 = fun1 T7360.Foo1
 
+-- RHS size: {terms: 2, types: 0, coercions: 0}
 T7360.fun4 :: Int
 [GblId,
  Caf=NoCafRefs,
@@ -35,6 +39,7 @@ T7360.fun4 :: Int
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
 T7360.fun4 = I# 0#
 
+-- RHS size: {terms: 16, types: 12, coercions: 0}
 fun2 :: forall a. [a] -> ((), Int)
 [GblId,
  Arity=1,
diff --git a/testsuite/tests/simplCore/should_compile/T9400.stderr b/testsuite/tests/simplCore/should_compile/T9400.stderr
index 2600dd00ba..5216d1ed5f 100644
--- a/testsuite/tests/simplCore/should_compile/T9400.stderr
+++ b/testsuite/tests/simplCore/should_compile/T9400.stderr
@@ -2,6 +2,7 @@
 ==================== Tidy Core ====================
 Result size of Tidy Core = {terms: 23, types: 16, coercions: 0}
 
+-- RHS size: {terms: 22, types: 14, coercions: 0}
 main :: IO ()
 [GblId, Str=DmdType]
 main =
diff --git a/testsuite/tests/simplCore/should_compile/all.T b/testsuite/tests/simplCore/should_compile/all.T
index ee2f63170b..b675077fda 100644
--- a/testsuite/tests/simplCore/should_compile/all.T
+++ b/testsuite/tests/simplCore/should_compile/all.T
@@ -106,6 +106,10 @@ test('T4918',
      run_command,
      ['$MAKE -s --no-print-directory T4918'])
 
+# This test flips too and fro about whether it passes
+# I'm not sure why it is so delicate, but it greps the
+# result of -ddump-simpl, which is never advertised to
+# be very stable
 test('T4945',
      expect_broken(4945),
      run_command,
@@ -214,3 +218,8 @@ test('T10176', only_ways(['optasm']), compile, [''])
 test('T10180', only_ways(['optasm']), compile, [''])
 test('T10602', only_ways(['optasm']), multimod_compile, ['T10602','-v0'])
 test('T10627', only_ways(['optasm']), compile, [''])
+test('T10181', [expect_broken(10181), only_ways(['optasm'])], compile, [''])
+test('T10083',
+     expect_broken(10083),
+     run_command,
+     ['$MAKE -s --no-print-directory T10083'])
diff --git a/testsuite/tests/simplCore/should_compile/spec-inline.stderr b/testsuite/tests/simplCore/should_compile/spec-inline.stderr
index 4bc2226554..392d4fba73 100644
--- a/testsuite/tests/simplCore/should_compile/spec-inline.stderr
+++ b/testsuite/tests/simplCore/should_compile/spec-inline.stderr
@@ -2,12 +2,14 @@
 ==================== Tidy Core ====================
 Result size of Tidy Core = {terms: 162, types: 61, coercions: 0}
 
+-- RHS size: {terms: 2, types: 1, coercions: 0}
 Roman.foo3 :: Int
 [GblId, Str=DmdType b]
 Roman.foo3 =
   patError @ Int "spec-inline.hs:(19,5)-(29,25)|function go"#
 
 Rec {
+-- RHS size: {terms: 55, types: 9, coercions: 0}
 Roman.foo_$s$wgo [Occ=LoopBreaker] :: Int# -> Int# -> Int#
 [GblId, Arity=2, Caf=NoCafRefs, Str=DmdType <L,U><L,U>]
 Roman.foo_$s$wgo =
@@ -30,6 +32,7 @@ Roman.foo_$s$wgo =
     }
 end Rec }
 
+-- RHS size: {terms: 74, types: 22, coercions: 0}
 Roman.$wgo [InlPrag=[0]] :: Maybe Int -> Maybe Int -> Int#
 [GblId,
  Arity=2,
@@ -67,6 +70,7 @@ Roman.$wgo =
         }
     }
 
+-- RHS size: {terms: 9, types: 5, coercions: 0}
 Roman.foo_go [InlPrag=INLINE[0]] :: Maybe Int -> Maybe Int -> Int
 [GblId,
  Arity=2,
@@ -80,6 +84,7 @@ Roman.foo_go =
   \ (w :: Maybe Int) (w1 :: Maybe Int) ->
     case Roman.$wgo w w1 of ww { __DEFAULT -> I# ww }
 
+-- RHS size: {terms: 2, types: 0, coercions: 0}
 Roman.foo2 :: Int
 [GblId,
  Caf=NoCafRefs,
@@ -88,6 +93,7 @@ Roman.foo2 :: Int
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
 Roman.foo2 = I# 6#
 
+-- RHS size: {terms: 2, types: 1, coercions: 0}
 Roman.foo1 :: Maybe Int
 [GblId,
  Caf=NoCafRefs,
@@ -96,6 +102,7 @@ Roman.foo1 :: Maybe Int
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
 Roman.foo1 = Just @ Int Roman.foo2
 
+-- RHS size: {terms: 11, types: 4, coercions: 0}
 foo :: Int -> Int
 [GblId,
  Arity=1,