Make noinline more reliable

This patch makes the desugarer rewrite
   noinline (f d)  -->   noinline f d

This makes 'noinline' much more reliable: see #18995

It's explained in the improved Note [noinlineId magic]
in GHC.Types.Id.Make

3 files changed, 73 insertions, 1 deletions

diff --git a/testsuite/tests/simplCore/should_compile/T18995.hs b/testsuite/tests/simplCore/should_compile/T18995.hs
new file mode 100644
index 0000000000..052a03ea98
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T18995.hs
@@ -0,0 +1,6 @@
+module T18995 where
+
+import GHC.Magic ( noinline )
+
+foo :: IO ()
+foo = (noinline print) True
diff --git a/testsuite/tests/simplCore/should_compile/T18995.stderr b/testsuite/tests/simplCore/should_compile/T18995.stderr
new file mode 100644
index 0000000000..a1db26f6ec
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T18995.stderr
@@ -0,0 +1,66 @@
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+  = {terms: 19, types: 14, coercions: 12, joins: 0/0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+T18995.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+T18995.$trModule4 = "main"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+T18995.$trModule3 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+T18995.$trModule3 = GHC.Types.TrNameS T18995.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
+T18995.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+T18995.$trModule2 = "T18995"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+T18995.$trModule1 :: GHC.Types.TrName
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+T18995.$trModule1 = GHC.Types.TrNameS T18995.$trModule2
+
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
+T18995.$trModule :: GHC.Types.Module
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+T18995.$trModule
+  = GHC.Types.Module T18995.$trModule3 T18995.$trModule1
+
+-- RHS size: {terms: 4, types: 7, coercions: 12, joins: 0/0}
+foo :: IO ()
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=False, ConLike=False,
+         WorkFree=False, Expandable=False, Guidance=IF_ARGS [] 40 0}]
+foo
+  = noinline
+      @(forall a. Show a => a -> IO ())
+      (System.IO.print1
+       `cast` (forall (a :: <*>_N).
+               <Show a>_R
+               %<'Many>_N ->_R <a>_R
+               %<'Many>_N ->_R Sym (GHC.Types.N:IO[0] <()>_R)
+               :: (forall {a}.
+                   Show a =>
+                   a
+                   -> GHC.Prim.State# GHC.Prim.RealWorld
+                   -> (# GHC.Prim.State# GHC.Prim.RealWorld, () #))
+                  ~R# (forall {a}. Show a => a -> IO ())))
+      @Bool
+      GHC.Show.$fShowBool
+      GHC.Types.True
+
+
+
diff --git a/testsuite/tests/simplCore/should_compile/all.T b/testsuite/tests/simplCore/should_compile/all.T
index 76f9567f3d..3bfc8c5c09 100644
--- a/testsuite/tests/simplCore/should_compile/all.T
+++ b/testsuite/tests/simplCore/should_compile/all.T
@@ -341,4 +341,4 @@ test('T18649', normal, compile, ['-O -ddump-rules -Wno-simplifiable-class-constr
 test('T18747A', normal, compile, [''])
 test('T18747B', normal, compile, [''])
 test('T18815', only_ways(['optasm']), makefile_test, ['T18815'])
-
+test('T18995', [ grep_errmsg(r'print') ], compile, ['-O -ddump-simpl -dsuppress-uniques'])