Allow top-level string literals in Core (#8472)

This commits relaxes the invariants of the Core syntax so that a
top-level variable can be bound to a primitive string literal of type
Addr#.

This commit:

* Relaxes the invatiants of the Core, and allows top-level bindings whose
  type is Addr# as long as their RHS is either a primitive string literal or
  another variable.

* Allows the simplifier and the full-laziness transformer to float out
  primitive string literals to the top leve.

* Introduces the new StgGenTopBinding type to accomodate top-level Addr#
  bindings.

* Introduces a new type of labels in the object code, with the suffix "_bytes",
  for exported top-level Addr# bindings.

* Makes some built-in rules more robust. This was necessary to keep them
  functional after the above changes.

This is a continuation of D2554.

Rebasing notes:
This had two slightly suspicious performance regressions:

* T12425: bytes allocated regressed by roughly 5%
* T4029: bytes allocated regressed by a bit over 1%
* T13035: bytes allocated regressed by a bit over 5%

These deserve additional investigation.

Rebased by: bgamari.

Test Plan: ./validate --slow

Reviewers: goldfire, trofi, simonmar, simonpj, austin, hvr, bgamari

Reviewed By: trofi, simonpj, bgamari

Subscribers: trofi, simonpj, gridaphobe, thomie

Differential Revision: https://phabricator.haskell.org/D2605

GHC Trac Issues: #8472

24 files changed, 439 insertions, 132 deletions

diff --git a/testsuite/tests/deSugar/should_compile/T2431.stderr b/testsuite/tests/deSugar/should_compile/T2431.stderr
index 797c6c7776..a8da44b73f 100644
--- a/testsuite/tests/deSugar/should_compile/T2431.stderr
+++ b/testsuite/tests/deSugar/should_compile/T2431.stderr
@@ -1,6 +1,6 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 36, types: 30, coercions: 1}
+Result size of Tidy Core = {terms: 44, types: 34, coercions: 1}
 
 -- RHS size: {terms: 2, types: 4, coercions: 1}
 T2431.$WRefl [InlPrag=INLINE] :: forall a. a :~: a
@@ -21,25 +21,40 @@ absurd :: forall a. (Int :~: Bool) -> a
 [GblId, Arity=1, Caf=NoCafRefs, Str=<L,U>x]
 absurd = \ (@ a) (x :: Int :~: Bool) -> case x of { }
 
--- RHS size: {terms: 2, types: 0, coercions: 0}
-$trModule1 :: GHC.Types.TrName
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$trModule1 :: GHC.Prim.Addr#
 [GblId, Caf=NoCafRefs]
-$trModule1 = GHC.Types.TrNameS "main"#
+$trModule1 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 $trModule2 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs]
-$trModule2 = GHC.Types.TrNameS "T2431"#
+$trModule2 = GHC.Types.TrNameS $trModule1
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$trModule3 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs]
+$trModule3 = "T2431"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0}
+$trModule4 :: GHC.Types.TrName
+[GblId, Caf=NoCafRefs]
+$trModule4 = GHC.Types.TrNameS $trModule3
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 T2431.$trModule :: GHC.Types.Module
 [GblId, Caf=NoCafRefs]
-T2431.$trModule = GHC.Types.Module $trModule1 $trModule2
+T2431.$trModule = GHC.Types.Module $trModule2 $trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$tc'Refl1 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs]
+$tc'Refl1 = "'Refl"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-$tc'Refl1 :: GHC.Types.TrName
+$tc'Refl2 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs]
-$tc'Refl1 = GHC.Types.TrNameS "'Refl"#
+$tc'Refl2 = GHC.Types.TrNameS $tc'Refl1
 
 -- RHS size: {terms: 5, types: 0, coercions: 0}
 T2431.$tc'Refl :: GHC.Types.TyCon
@@ -49,12 +64,17 @@ T2431.$tc'Refl =
     15026191172322750497##
     3898273167927206410##
     T2431.$trModule
-    $tc'Refl1
+    $tc'Refl2
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$tc:~:1 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs]
+$tc:~:1 = ":~:"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-$tc:~:1 :: GHC.Types.TrName
+$tc:~:2 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs]
-$tc:~:1 = GHC.Types.TrNameS ":~:"#
+$tc:~:2 = GHC.Types.TrNameS $tc:~:1
 
 -- RHS size: {terms: 5, types: 0, coercions: 0}
 T2431.$tc:~: :: GHC.Types.TyCon
@@ -64,7 +84,7 @@ T2431.$tc:~: =
     9759653149176674453##
     12942818337407067047##
     T2431.$trModule
-    $tc:~:1
+    $tc:~:2
 
 
 
diff --git a/testsuite/tests/numeric/should_compile/T7116.stdout b/testsuite/tests/numeric/should_compile/T7116.stdout
index 9f7837bdc7..7fe4d93d87 100644
--- a/testsuite/tests/numeric/should_compile/T7116.stdout
+++ b/testsuite/tests/numeric/should_compile/T7116.stdout
@@ -1,15 +1,31 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 46, types: 23, coercions: 0}
+Result size of Tidy Core = {terms: 50, types: 25, coercions: 0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T7116.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+T7116.$trModule4 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-T7116.$trModule2 :: GHC.Types.TrName
+T7116.$trModule3 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 20}]
-T7116.$trModule2 = GHC.Types.TrNameS "main"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T7116.$trModule3 = GHC.Types.TrNameS T7116.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T7116.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+T7116.$trModule2 = "T7116"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 T7116.$trModule1 :: GHC.Types.TrName
@@ -17,8 +33,8 @@ T7116.$trModule1 :: GHC.Types.TrName
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 20}]
-T7116.$trModule1 = GHC.Types.TrNameS "T7116"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T7116.$trModule1 = GHC.Types.TrNameS T7116.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 T7116.$trModule :: GHC.Types.Module
@@ -28,7 +44,7 @@ T7116.$trModule :: GHC.Types.Module
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 30}]
 T7116.$trModule =
-  GHC.Types.Module T7116.$trModule2 T7116.$trModule1
+  GHC.Types.Module T7116.$trModule3 T7116.$trModule1
 
 -- RHS size: {terms: 8, types: 3, coercions: 0}
 dr :: Double -> Double
diff --git a/testsuite/tests/perf/compiler/all.T b/testsuite/tests/perf/compiler/all.T
index 499650bd69..797cbd9d94 100644
--- a/testsuite/tests/perf/compiler/all.T
+++ b/testsuite/tests/perf/compiler/all.T
@@ -39,7 +39,7 @@ test('T1969',
              # 2013-11-13 17 (x86/Windows, 64bit machine)
              # 2015-07-11 21 (x86/Linux, 64bit machine) use +RTS -G1
              # 2016-04-06 30 (x86/Linux, 64bit machine)
-           (wordsize(64), 55, 20)]),
+           (wordsize(64), 68, 20)]),
              #            28 (amd64/Linux)
              #            34 (amd64/Linux)
              # 2012-09-20 23 (amd64/Linux)
@@ -51,6 +51,8 @@ test('T1969',
              # 2013-09-11 30, 15 (adapt to Phab CI)
              # 2015-06-03 41, (amd64/Linux) use +RTS -G1
              # 2015-10-28 55, (amd64/Linux) emit Typeable at definition site
+             # 2016-10-20 68, (amd64/Linux) allow top-level string literals
+             #                See the comment 16 on #8472.
       compiler_stats_num_field('max_bytes_used',
           [(platform('i386-unknown-mingw32'), 5719436, 20),
                                  # 2010-05-17 5717704 (x86/Windows)
@@ -827,7 +829,7 @@ test('T9233',
 test('T10370',
      [ only_ways(['optasm']),
        compiler_stats_num_field('max_bytes_used', # Note [residency]
-          [(wordsize(64), 33049168, 15),
+          [(wordsize(64), 38221184, 15),
           # 2015-10-22    19548720
           # 2016-02-24    22823976   Changing Levity to RuntimeRep; not sure why this regresses though, even after some analysis
           # 2016-04-14    28256896   final demand analyzer run
@@ -838,14 +840,17 @@ test('T10370',
           #     affected stats on bootstrapped GHC.  However,
           #     when I set -i0.01 with profiling, the heap profiles
           #     were identical, so I think it's just GC noise.
+          # 2016-10-20    38221184   Allow top-level string literals.
+          #                          See the comment 16 on #8472.
            (wordsize(32), 11371496, 15),
           # 2015-10-22    11371496
           ]),
        compiler_stats_num_field('peak_megabytes_allocated', # Note [residency]
-          [(wordsize(64), 121, 15),
+          [(wordsize(64), 146, 15),
           # 2015-10-22     76
           # 2016-04-14    101 final demand analyzer run
           # 2016-08-08    121 see above
+          # 2017-01-18    146 Allow top-level string literals in Core
            (wordsize(32),  39, 15),
           # 2015-10-22     39
           ]),
@@ -883,8 +888,9 @@ test('T12227',
 test('T12425',
      [ only_ways(['optasm']),
        compiler_stats_num_field('bytes allocated',
-          [(wordsize(64), 125831400, 5),
+          [(wordsize(64), 133380960, 5),
           # initial:    125831400
+          # 2017-01-18: 133380960  Allow top-level string literals in Core
           ]),
      ],
      compile,
@@ -906,8 +912,9 @@ test('T12234',
 test('T13035',
      [ only_ways(['normal']),
        compiler_stats_num_field('bytes allocated',
-          [(wordsize(64), 90595208, 5),
+          [(wordsize(64), 95269000, 5),
           # 2017-01-05   90595208 initial
+          # 2017-01-19   95269000 Allow top-level string literals in Core
           ]),
      ],
      compile,
diff --git a/testsuite/tests/perf/should_run/T8472.hs b/testsuite/tests/perf/should_run/T8472.hs
new file mode 100644
index 0000000000..24f0ec7811
--- /dev/null
+++ b/testsuite/tests/perf/should_run/T8472.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE MagicHash #-}
+
+module Main (f, main) where
+
+import GHC.Exts(Ptr(..))
+import Foreign.Ptr
+
+-- We should be able to inline this function.
+f :: Ptr Int -> Int -> Int
+f =
+  let x = "foo"#
+  in \p n -> n + (Ptr x `minusPtr` p)
+
+main :: IO ()
+main = print $ x `mod` 2 == (x + 4) `mod` 2
+  where
+    x = go (10000::Int) 4
+    go 0 a = a
+    go n a = go (n-1) (f nullPtr a)
diff --git a/testsuite/tests/perf/should_run/T8472.stdout b/testsuite/tests/perf/should_run/T8472.stdout
new file mode 100644
index 0000000000..0ca95142bb
--- /dev/null
+++ b/testsuite/tests/perf/should_run/T8472.stdout
@@ -0,0 +1 @@
+True
diff --git a/testsuite/tests/perf/should_run/all.T b/testsuite/tests/perf/should_run/all.T
index 333970ca57..1560e7ea2e 100644
--- a/testsuite/tests/perf/should_run/all.T
+++ b/testsuite/tests/perf/should_run/all.T
@@ -446,6 +446,14 @@ test('T9339',
      compile_and_run,
      ['-O2'])
 
+test('T8472',
+     [stats_num_field('bytes allocated',
+                      [ (wordsize(32),    50000, 80)
+                      , (wordsize(64),    51424, 80) ]),
+      only_ways(['normal'])],
+     compile_and_run,
+     ['-O2'])
+
 test('T12996',
      [stats_num_field('bytes allocated',
                       [ (wordsize(64),    76776, 5) ]),
diff --git a/testsuite/tests/perf/space_leaks/all.T b/testsuite/tests/perf/space_leaks/all.T
index 9acd157543..56a58cb586 100644
--- a/testsuite/tests/perf/space_leaks/all.T
+++ b/testsuite/tests/perf/space_leaks/all.T
@@ -64,7 +64,7 @@ test('T4029',
             # 2016-07-13: 92 (amd64/Linux)           Changes to tidyType
             # 2016-09-01: 71 (amd64/Linux)           Restore w/w limit (#11565)
       stats_num_field('max_bytes_used',
-          [(wordsize(64), 21387048 , 5)]),
+          [(wordsize(64), 21670448 , 5)]),
             # 2016-02-26: 24071720 (amd64/Linux)     INITIAL
             # 2016-04-21: 25542832 (amd64/Linux)
             # 2016-05-23: 25247216 (amd64/Linux)     Use -G1
@@ -73,6 +73,7 @@ test('T4029',
             # 2016-09-01: 21648488 (amd64/Linux)     Restore w/w limit (#11565)
             # 2016-10-13: 20325248 (amd64/Linux)     Creep (downwards, yay!)
             # 2016-11-14: 21387048 (amd64/Linux)     Creep back upwards :(
+            # 2017-01-18: 21670448 (amd64/Linux)     Float string literals to toplevel
       extra_hc_opts('+RTS -G1 -RTS' ),
       ],
      ghci_script,
diff --git a/testsuite/tests/roles/should_compile/Roles13.stderr b/testsuite/tests/roles/should_compile/Roles13.stderr
index f74c3abbb9..20206e28df 100644
--- a/testsuite/tests/roles/should_compile/Roles13.stderr
+++ b/testsuite/tests/roles/should_compile/Roles13.stderr
@@ -1,6 +1,6 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 51, types: 20, coercions: 5}
+Result size of Tidy Core = {terms: 63, types: 26, coercions: 5}
 
 -- RHS size: {terms: 2, types: 2, coercions: 0}
 convert1 :: Wrap Age -> Wrap Age
@@ -15,25 +15,40 @@ convert =
   `cast` (<Wrap Age>_R -> Roles13.N:Wrap[0] Roles13.N:Age[0]
           :: ((Wrap Age -> Wrap Age) :: *) ~R# ((Wrap Age -> Int) :: *))
 
--- RHS size: {terms: 2, types: 0, coercions: 0}
-$trModule1 :: GHC.Types.TrName
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$trModule1 :: GHC.Prim.Addr#
 [GblId, Caf=NoCafRefs]
-$trModule1 = GHC.Types.TrNameS "main"#
+$trModule1 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 $trModule2 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs]
-$trModule2 = GHC.Types.TrNameS "Roles13"#
+$trModule2 = GHC.Types.TrNameS $trModule1
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$trModule3 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs]
+$trModule3 = "Roles13"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0}
+$trModule4 :: GHC.Types.TrName
+[GblId, Caf=NoCafRefs]
+$trModule4 = GHC.Types.TrNameS $trModule3
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 Roles13.$trModule :: GHC.Types.Module
 [GblId, Caf=NoCafRefs]
-Roles13.$trModule = GHC.Types.Module $trModule1 $trModule2
+Roles13.$trModule = GHC.Types.Module $trModule2 $trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$tc'MkAge1 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs]
+$tc'MkAge1 = "'MkAge"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-$tc'MkAge1 :: GHC.Types.TrName
+$tc'MkAge2 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs]
-$tc'MkAge1 = GHC.Types.TrNameS "'MkAge"#
+$tc'MkAge2 = GHC.Types.TrNameS $tc'MkAge1
 
 -- RHS size: {terms: 5, types: 0, coercions: 0}
 Roles13.$tc'MkAge :: GHC.Types.TyCon
@@ -43,12 +58,17 @@ Roles13.$tc'MkAge =
     1226019810264079099##
     12180888342844277416##
     Roles13.$trModule
-    $tc'MkAge1
+    $tc'MkAge2
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$tcAge1 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs]
+$tcAge1 = "Age"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-$tcAge1 :: GHC.Types.TrName
+$tcAge2 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs]
-$tcAge1 = GHC.Types.TrNameS "Age"#
+$tcAge2 = GHC.Types.TrNameS $tcAge1
 
 -- RHS size: {terms: 5, types: 0, coercions: 0}
 Roles13.$tcAge :: GHC.Types.TyCon
@@ -58,12 +78,17 @@ Roles13.$tcAge =
     18304088376370610314##
     1954648846714895105##
     Roles13.$trModule
-    $tcAge1
+    $tcAge2
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$tc'MkWrap1 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs]
+$tc'MkWrap1 = "'MkWrap"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-$tc'MkWrap1 :: GHC.Types.TrName
+$tc'MkWrap2 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs]
-$tc'MkWrap1 = GHC.Types.TrNameS "'MkWrap"#
+$tc'MkWrap2 = GHC.Types.TrNameS $tc'MkWrap1
 
 -- RHS size: {terms: 5, types: 0, coercions: 0}
 Roles13.$tc'MkWrap :: GHC.Types.TyCon
@@ -73,12 +98,17 @@ Roles13.$tc'MkWrap =
     12402878715225676312##
     13345418993613492500##
     Roles13.$trModule
-    $tc'MkWrap1
+    $tc'MkWrap2
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$tcWrap1 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs]
+$tcWrap1 = "Wrap"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-$tcWrap1 :: GHC.Types.TrName
+$tcWrap2 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs]
-$tcWrap1 = GHC.Types.TrNameS "Wrap"#
+$tcWrap2 = GHC.Types.TrNameS $tcWrap1
 
 -- RHS size: {terms: 5, types: 0, coercions: 0}
 Roles13.$tcWrap :: GHC.Types.TyCon
@@ -88,7 +118,7 @@ Roles13.$tcWrap =
     5278920226786541118##
     14554440859491798587##
     Roles13.$trModule
-    $tcWrap1
+    $tcWrap2
 
 
 
diff --git a/testsuite/tests/simplCore/should_compile/Makefile b/testsuite/tests/simplCore/should_compile/Makefile
index 224e84c825..5a465d9818 100644
--- a/testsuite/tests/simplCore/should_compile/Makefile
+++ b/testsuite/tests/simplCore/should_compile/Makefile
@@ -185,3 +185,8 @@ T13025:
 	'$(TEST_HC)' $(TEST_HC_OPTS) -c -O T13025a.hs
 	-'$(TEST_HC)' $(TEST_HC_OPTS) -c -O T13025.hs -ddump-simpl | grep -c HEq_sc
 	# No lines should match 'HEq_sc' so wc should output zeros
+
+.PHONY: str-rules
+str-rules:
+	$(RM) -f str-rules.hi str-rules.o
+	'$(TEST_HC)' $(TEST_HC_OPTS) -c -O str-rules.hs -ddump-simpl | grep -o '"@@@[^"].*"#' | sort
diff --git a/testsuite/tests/simplCore/should_compile/T3234.stderr b/testsuite/tests/simplCore/should_compile/T3234.stderr
index da96b43d9d..9d87b3ecc1 100644
--- a/testsuite/tests/simplCore/should_compile/T3234.stderr
+++ b/testsuite/tests/simplCore/should_compile/T3234.stderr
@@ -1,6 +1,6 @@
 
 ==================== FloatOut stats: ====================
-1 Lets floated to top level; 0 Lets floated elsewhere; from 1 Lambda groups
+2 Lets floated to top level; 0 Lets floated elsewhere; from 1 Lambda groups
 
 
 
@@ -10,9 +10,9 @@
 
 
 ==================== Grand total simplifier statistics ====================
-Total ticks:     51
+Total ticks:     54
 
-14 PreInlineUnconditionally
+15 PreInlineUnconditionally
   1 n
   1 g
   1 a
@@ -27,6 +27,7 @@ Total ticks:     51
   1 a
   1 lvl
   1 lvl
+  1 lvl
 4 PostInlineUnconditionally
   1 c
   1 n
@@ -39,7 +40,7 @@ Total ticks:     51
   1 fold/build
   1 unpack
   1 unpack-list
-2 LetFloatFromLet 2
+4 LetFloatFromLet 4
 25 BetaReduction
   1 a
   1 c
diff --git a/testsuite/tests/simplCore/should_compile/T3717.stderr b/testsuite/tests/simplCore/should_compile/T3717.stderr
index a7c1e55c52..f9adeb28da 100644
--- a/testsuite/tests/simplCore/should_compile/T3717.stderr
+++ b/testsuite/tests/simplCore/should_compile/T3717.stderr
@@ -1,15 +1,31 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 32, types: 13, coercions: 0}
+Result size of Tidy Core = {terms: 36, types: 15, coercions: 0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T3717.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+T3717.$trModule4 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-T3717.$trModule2 :: GHC.Types.TrName
+T3717.$trModule3 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 20}]
-T3717.$trModule2 = GHC.Types.TrNameS "main"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T3717.$trModule3 = GHC.Types.TrNameS T3717.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T3717.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+T3717.$trModule2 = "T3717"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 T3717.$trModule1 :: GHC.Types.TrName
@@ -17,8 +33,8 @@ T3717.$trModule1 :: GHC.Types.TrName
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 20}]
-T3717.$trModule1 = GHC.Types.TrNameS "T3717"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T3717.$trModule1 = GHC.Types.TrNameS T3717.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 T3717.$trModule :: GHC.Types.Module
@@ -28,7 +44,7 @@ T3717.$trModule :: GHC.Types.Module
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 30}]
 T3717.$trModule =
-  GHC.Types.Module T3717.$trModule2 T3717.$trModule1
+  GHC.Types.Module T3717.$trModule3 T3717.$trModule1
 
 Rec {
 -- RHS size: {terms: 10, types: 2, coercions: 0}
diff --git a/testsuite/tests/simplCore/should_compile/T3772.stdout b/testsuite/tests/simplCore/should_compile/T3772.stdout
index d70c0eee55..76936e336f 100644
--- a/testsuite/tests/simplCore/should_compile/T3772.stdout
+++ b/testsuite/tests/simplCore/should_compile/T3772.stdout
@@ -1,6 +1,6 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 36, types: 14, coercions: 0}
+Result size of Tidy Core = {terms: 40, types: 16, coercions: 0}
 
 Rec {
 -- RHS size: {terms: 10, types: 2, coercions: 0}
@@ -26,23 +26,39 @@ foo =
     }
     }
 
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T3772.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+T3772.$trModule2 = "T3772"#
+
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 T3772.$trModule1 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 20}]
-T3772.$trModule1 = GHC.Types.TrNameS "T3772"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T3772.$trModule1 = GHC.Types.TrNameS T3772.$trModule2
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T3772.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+T3772.$trModule4 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-T3772.$trModule2 :: GHC.Types.TrName
+T3772.$trModule3 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 20}]
-T3772.$trModule2 = GHC.Types.TrNameS "main"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T3772.$trModule3 = GHC.Types.TrNameS T3772.$trModule4
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 T3772.$trModule :: GHC.Types.Module
@@ -52,7 +68,7 @@ T3772.$trModule :: GHC.Types.Module
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 30}]
 T3772.$trModule =
-  GHC.Types.Module T3772.$trModule2 T3772.$trModule1
+  GHC.Types.Module T3772.$trModule3 T3772.$trModule1
 
 
 
diff --git a/testsuite/tests/simplCore/should_compile/T4908.stderr b/testsuite/tests/simplCore/should_compile/T4908.stderr
index 7136bd1f51..e9957bf9de 100644
--- a/testsuite/tests/simplCore/should_compile/T4908.stderr
+++ b/testsuite/tests/simplCore/should_compile/T4908.stderr
@@ -1,15 +1,31 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 64, types: 41, coercions: 0}
+Result size of Tidy Core = {terms: 68, types: 43, coercions: 0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T4908.$trModule4 :: Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+T4908.$trModule4 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-T4908.$trModule2 :: TrName
+T4908.$trModule3 :: TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 20}]
-T4908.$trModule2 = GHC.Types.TrNameS "main"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T4908.$trModule3 = GHC.Types.TrNameS T4908.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T4908.$trModule2 :: Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+T4908.$trModule2 = "T4908"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 T4908.$trModule1 :: TrName
@@ -17,8 +33,8 @@ T4908.$trModule1 :: TrName
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 20}]
-T4908.$trModule1 = GHC.Types.TrNameS "T4908"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T4908.$trModule1 = GHC.Types.TrNameS T4908.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 T4908.$trModule :: Module
@@ -28,7 +44,7 @@ T4908.$trModule :: Module
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 30}]
 T4908.$trModule =
-  GHC.Types.Module T4908.$trModule2 T4908.$trModule1
+  GHC.Types.Module T4908.$trModule3 T4908.$trModule1
 
 Rec {
 -- RHS size: {terms: 19, types: 5, coercions: 0}
diff --git a/testsuite/tests/simplCore/should_compile/T4930.stderr b/testsuite/tests/simplCore/should_compile/T4930.stderr
index 7e51aa68be..365584d3d0 100644
--- a/testsuite/tests/simplCore/should_compile/T4930.stderr
+++ b/testsuite/tests/simplCore/should_compile/T4930.stderr
@@ -1,15 +1,31 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 45, types: 17, coercions: 0}
+Result size of Tidy Core = {terms: 49, types: 19, coercions: 0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T4930.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+T4930.$trModule4 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-T4930.$trModule2 :: GHC.Types.TrName
+T4930.$trModule3 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 20}]
-T4930.$trModule2 = GHC.Types.TrNameS "main"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T4930.$trModule3 = GHC.Types.TrNameS T4930.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T4930.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+T4930.$trModule2 = "T4930"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 T4930.$trModule1 :: GHC.Types.TrName
@@ -17,8 +33,8 @@ T4930.$trModule1 :: GHC.Types.TrName
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 20}]
-T4930.$trModule1 = GHC.Types.TrNameS "T4930"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T4930.$trModule1 = GHC.Types.TrNameS T4930.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 T4930.$trModule :: GHC.Types.Module
@@ -28,7 +44,7 @@ T4930.$trModule :: GHC.Types.Module
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 30}]
 T4930.$trModule =
-  GHC.Types.Module T4930.$trModule2 T4930.$trModule1
+  GHC.Types.Module T4930.$trModule3 T4930.$trModule1
 
 Rec {
 -- RHS size: {terms: 23, types: 6, coercions: 0}
diff --git a/testsuite/tests/simplCore/should_compile/T7360.stderr b/testsuite/tests/simplCore/should_compile/T7360.stderr
index 2b0984c8d5..2e387b27bc 100644
--- a/testsuite/tests/simplCore/should_compile/T7360.stderr
+++ b/testsuite/tests/simplCore/should_compile/T7360.stderr
@@ -1,6 +1,6 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 82, types: 42, coercions: 0}
+Result size of Tidy Core = {terms: 94, types: 48, coercions: 0}
 
 -- RHS size: {terms: 6, types: 3, coercions: 0}
 T7360.$WFoo3 [InlPrag=INLINE] :: Int -> Foo
@@ -66,14 +66,30 @@ fun2 =
          }
      })
 
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T7360.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+T7360.$trModule4 = "main"#
+
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-T7360.$trModule2 :: GHC.Types.TrName
+T7360.$trModule3 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 20}]
-T7360.$trModule2 = GHC.Types.TrNameS "main"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T7360.$trModule3 = GHC.Types.TrNameS T7360.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T7360.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+T7360.$trModule2 = "T7360"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 T7360.$trModule1 :: GHC.Types.TrName
@@ -81,8 +97,8 @@ T7360.$trModule1 :: GHC.Types.TrName
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 20}]
-T7360.$trModule1 = GHC.Types.TrNameS "T7360"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T7360.$trModule1 = GHC.Types.TrNameS T7360.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 T7360.$trModule :: GHC.Types.Module
@@ -92,16 +108,24 @@ T7360.$trModule :: GHC.Types.Module
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 30}]
 T7360.$trModule =
-  GHC.Types.Module T7360.$trModule2 T7360.$trModule1
+  GHC.Types.Module T7360.$trModule3 T7360.$trModule1
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T7360.$tc'Foo9 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+T7360.$tc'Foo9 = "'Foo3"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-T7360.$tc'Foo6 :: GHC.Types.TrName
+T7360.$tc'Foo8 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 20}]
-T7360.$tc'Foo6 = GHC.Types.TrNameS "'Foo3"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T7360.$tc'Foo8 = GHC.Types.TrNameS T7360.$tc'Foo9
 
 -- RHS size: {terms: 5, types: 0, coercions: 0}
 T7360.$tc'Foo3 :: GHC.Types.TyCon
@@ -115,16 +139,24 @@ T7360.$tc'Foo3 =
     10507205234936349519##
     8302184214013227554##
     T7360.$trModule
-    T7360.$tc'Foo6
+    T7360.$tc'Foo8
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T7360.$tc'Foo7 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+T7360.$tc'Foo7 = "'Foo2"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-T7360.$tc'Foo5 :: GHC.Types.TrName
+T7360.$tc'Foo6 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 20}]
-T7360.$tc'Foo5 = GHC.Types.TrNameS "'Foo2"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T7360.$tc'Foo6 = GHC.Types.TrNameS T7360.$tc'Foo7
 
 -- RHS size: {terms: 5, types: 0, coercions: 0}
 T7360.$tc'Foo2 :: GHC.Types.TyCon
@@ -138,7 +170,15 @@ T7360.$tc'Foo2 =
     9825259700232563546##
     11056638024476048052##
     T7360.$trModule
-    T7360.$tc'Foo5
+    T7360.$tc'Foo6
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T7360.$tc'Foo5 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+T7360.$tc'Foo5 = "'Foo1"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 T7360.$tc'Foo4 :: GHC.Types.TrName
@@ -146,8 +186,8 @@ T7360.$tc'Foo4 :: GHC.Types.TrName
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 20}]
-T7360.$tc'Foo4 = GHC.Types.TrNameS "'Foo1"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T7360.$tc'Foo4 = GHC.Types.TrNameS T7360.$tc'Foo5
 
 -- RHS size: {terms: 5, types: 0, coercions: 0}
 T7360.$tc'Foo1 :: GHC.Types.TyCon
@@ -163,14 +203,22 @@ T7360.$tc'Foo1 =
     T7360.$trModule
     T7360.$tc'Foo4
 
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+T7360.$tcFoo2 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+T7360.$tcFoo2 = "Foo"#
+
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 T7360.$tcFoo1 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 20}]
-T7360.$tcFoo1 = GHC.Types.TrNameS "Foo"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+T7360.$tcFoo1 = GHC.Types.TrNameS T7360.$tcFoo2
 
 -- RHS size: {terms: 5, types: 0, coercions: 0}
 T7360.$tcFoo :: GHC.Types.TyCon
diff --git a/testsuite/tests/simplCore/should_compile/T8274.stdout b/testsuite/tests/simplCore/should_compile/T8274.stdout
index 43830c7135..df8253f510 100644
--- a/testsuite/tests/simplCore/should_compile/T8274.stdout
+++ b/testsuite/tests/simplCore/should_compile/T8274.stdout
@@ -1,12 +1,18 @@
 p = T8274.Positives 42# 4.23# 4.23## '4'# 4##
 n = T8274.Negatives -4# -4.0# -4.0##
-T8274.$trModule2 = GHC.Types.TrNameS "main"#
-T8274.$trModule1 = GHC.Types.TrNameS "T8274"#
-T8274.$tc'Positives1 = GHC.Types.TrNameS "'Positives"#
+T8274.$trModule4 :: Addr#
+T8274.$trModule4 = "main"#
+T8274.$trModule2 :: Addr#
+T8274.$trModule2 = "T8274"#
+T8274.$tc'Positives2 :: Addr#
+T8274.$tc'Positives2 = "'Positives"#
 T8274.$tc'Positives = GHC.Types.TyCon 14732531009298850569## 4925356269917933860## T8274.$trModule T8274.$tc'Positives1
-T8274.$tcP1 = GHC.Types.TrNameS "P"#
+T8274.$tcP2 :: Addr#
+T8274.$tcP2 = "P"#
 T8274.$tcP = GHC.Types.TyCon 11095028091707994303## 9476557054198009608## T8274.$trModule T8274.$tcP1
-T8274.$tc'Negatives1 = GHC.Types.TrNameS "'Negatives"#
+T8274.$tc'Negatives2 :: Addr#
+T8274.$tc'Negatives2 = "'Negatives"#
 T8274.$tc'Negatives = GHC.Types.TyCon 15950179315687996644## 11481167534507418130## T8274.$trModule T8274.$tc'Negatives1
-T8274.$tcN1 = GHC.Types.TrNameS "N"#
+T8274.$tcN2 :: Addr#
+T8274.$tcN2 = "N"#
 T8274.$tcN = GHC.Types.TyCon 7479687563082171902## 17616649989360543185## T8274.$trModule T8274.$tcN1
diff --git a/testsuite/tests/simplCore/should_compile/T9400.stderr b/testsuite/tests/simplCore/should_compile/T9400.stderr
index bab1751a86..92979b36b1 100644
--- a/testsuite/tests/simplCore/should_compile/T9400.stderr
+++ b/testsuite/tests/simplCore/should_compile/T9400.stderr
@@ -1,21 +1,31 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 33, types: 20, coercions: 0}
+Result size of Tidy Core = {terms: 37, types: 22, coercions: 0}
 
--- RHS size: {terms: 2, types: 0, coercions: 0}
-$trModule1 :: TrName
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$trModule1 :: Addr#
 [GblId, Caf=NoCafRefs]
-$trModule1 = GHC.Types.TrNameS "main"#
+$trModule1 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 $trModule2 :: TrName
 [GblId, Caf=NoCafRefs]
-$trModule2 = GHC.Types.TrNameS "T9400"#
+$trModule2 = GHC.Types.TrNameS $trModule1
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+$trModule3 :: Addr#
+[GblId, Caf=NoCafRefs]
+$trModule3 = "T9400"#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0}
+$trModule4 :: TrName
+[GblId, Caf=NoCafRefs]
+$trModule4 = GHC.Types.TrNameS $trModule3
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 T9400.$trModule :: Module
 [GblId, Caf=NoCafRefs]
-T9400.$trModule = GHC.Types.Module $trModule1 $trModule2
+T9400.$trModule = GHC.Types.Module $trModule2 $trModule4
 
 -- RHS size: {terms: 22, types: 15, coercions: 0}
 main :: IO ()
diff --git a/testsuite/tests/simplCore/should_compile/all.T b/testsuite/tests/simplCore/should_compile/all.T
index 19e9f1d3a4..2ede2468ee 100644
--- a/testsuite/tests/simplCore/should_compile/all.T
+++ b/testsuite/tests/simplCore/should_compile/all.T
@@ -263,3 +263,7 @@ test('T13025',
      ['$MAKE -s --no-print-directory T13025'])
 test('T13156', normal, run_command, ['$MAKE -s --no-print-directory T13156'])
 test('T11444', normal, compile, [''])
+test('str-rules',
+     normal,
+     run_command,
+     ['$MAKE -s --no-print-directory str-rules'])
diff --git a/testsuite/tests/simplCore/should_compile/noinline01.stderr b/testsuite/tests/simplCore/should_compile/noinline01.stderr
index b100172381..1bb98e57b4 100644
--- a/testsuite/tests/simplCore/should_compile/noinline01.stderr
+++ b/testsuite/tests/simplCore/should_compile/noinline01.stderr
@@ -9,17 +9,25 @@ Noinline01.g :: GHC.Types.Bool
 [GblId] =
     \u [] Noinline01.f GHC.Types.False;
 
-Noinline01.$trModule2 :: GHC.Types.TrName
+Noinline01.$trModule4 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs, Unf=OtherCon []] =
+    "main"#;
+
+Noinline01.$trModule3 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs, Str=m1, Unf=OtherCon []] =
-    NO_CCS GHC.Types.TrNameS! ["main"#];
+    NO_CCS GHC.Types.TrNameS! [Noinline01.$trModule4];
+
+Noinline01.$trModule2 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs, Unf=OtherCon []] =
+    "Noinline01"#;
 
 Noinline01.$trModule1 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs, Str=m1, Unf=OtherCon []] =
-    NO_CCS GHC.Types.TrNameS! ["Noinline01"#];
+    NO_CCS GHC.Types.TrNameS! [Noinline01.$trModule2];
 
 Noinline01.$trModule :: GHC.Types.Module
 [GblId, Caf=NoCafRefs, Str=m, Unf=OtherCon []] =
-    NO_CCS GHC.Types.Module! [Noinline01.$trModule2
+    NO_CCS GHC.Types.Module! [Noinline01.$trModule3
                               Noinline01.$trModule1];
 
 
@@ -34,17 +42,25 @@ Noinline01.g :: GHC.Types.Bool
 [GblId] =
     \u [] Noinline01.f GHC.Types.False;
 
-Noinline01.$trModule2 :: GHC.Types.TrName
+Noinline01.$trModule4 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs, Unf=OtherCon []] =
+    "main"#;
+
+Noinline01.$trModule3 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs, Str=m1, Unf=OtherCon []] =
-    NO_CCS GHC.Types.TrNameS! ["main"#];
+    NO_CCS GHC.Types.TrNameS! [Noinline01.$trModule4];
+
+Noinline01.$trModule2 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs, Unf=OtherCon []] =
+    "Noinline01"#;
 
 Noinline01.$trModule1 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs, Str=m1, Unf=OtherCon []] =
-    NO_CCS GHC.Types.TrNameS! ["Noinline01"#];
+    NO_CCS GHC.Types.TrNameS! [Noinline01.$trModule2];
 
 Noinline01.$trModule :: GHC.Types.Module
 [GblId, Caf=NoCafRefs, Str=m, Unf=OtherCon []] =
-    NO_CCS GHC.Types.Module! [Noinline01.$trModule2
+    NO_CCS GHC.Types.Module! [Noinline01.$trModule3
                               Noinline01.$trModule1];
 
 
diff --git a/testsuite/tests/simplCore/should_compile/par01.stderr b/testsuite/tests/simplCore/should_compile/par01.stderr
index 90d467f71c..4ccb9d892b 100644
--- a/testsuite/tests/simplCore/should_compile/par01.stderr
+++ b/testsuite/tests/simplCore/should_compile/par01.stderr
@@ -1,6 +1,6 @@
 
 ==================== CorePrep ====================
-Result size of CorePrep = {terms: 18, types: 8, coercions: 0}
+Result size of CorePrep = {terms: 22, types: 10, coercions: 0}
 
 Rec {
 -- RHS size: {terms: 7, types: 3, coercions: 0}
@@ -13,21 +13,31 @@ Par01.depth =
     }
 end Rec }
 
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+Par01.$trModule4 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs, Unf=OtherCon []]
+Par01.$trModule4 = "main"#
+
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-Par01.$trModule2 :: GHC.Types.TrName
+Par01.$trModule3 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs, Str=m1, Unf=OtherCon []]
-Par01.$trModule2 = GHC.Types.TrNameS "main"#
+Par01.$trModule3 = GHC.Types.TrNameS Par01.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+Par01.$trModule2 :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs, Unf=OtherCon []]
+Par01.$trModule2 = "Par01"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 Par01.$trModule1 :: GHC.Types.TrName
 [GblId, Caf=NoCafRefs, Str=m1, Unf=OtherCon []]
-Par01.$trModule1 = GHC.Types.TrNameS "Par01"#
+Par01.$trModule1 = GHC.Types.TrNameS Par01.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 Par01.$trModule :: GHC.Types.Module
 [GblId, Caf=NoCafRefs, Str=m, Unf=OtherCon []]
 Par01.$trModule =
-  GHC.Types.Module Par01.$trModule2 Par01.$trModule1
+  GHC.Types.Module Par01.$trModule3 Par01.$trModule1
 
 
 
diff --git a/testsuite/tests/simplCore/should_compile/rule2.stderr b/testsuite/tests/simplCore/should_compile/rule2.stderr
index 844afc63d6..572fac36a8 100644
--- a/testsuite/tests/simplCore/should_compile/rule2.stderr
+++ b/testsuite/tests/simplCore/should_compile/rule2.stderr
@@ -10,14 +10,14 @@
 
 
 ==================== Grand total simplifier statistics ====================
-Total ticks:     13
+Total ticks:     15
 
 2 PreInlineUnconditionally
   1 f
   1 lvl
 1 UnfoldingDone 1 Roman.bar
 1 RuleFired 1 foo/bar
-1 LetFloatFromLet 1
+3 LetFloatFromLet 3
 1 EtaReduction 1 ds
 7 BetaReduction
   1 f
diff --git a/testsuite/tests/simplCore/should_compile/spec-inline.stderr b/testsuite/tests/simplCore/should_compile/spec-inline.stderr
index e7fc531a43..0de46d181d 100644
--- a/testsuite/tests/simplCore/should_compile/spec-inline.stderr
+++ b/testsuite/tests/simplCore/should_compile/spec-inline.stderr
@@ -1,15 +1,31 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 172, types: 65, coercions: 0}
+Result size of Tidy Core = {terms: 178, types: 68, coercions: 0}
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+Roman.$trModule4 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+Roman.$trModule4 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
-Roman.$trModule2 :: GHC.Types.TrName
+Roman.$trModule3 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 20}]
-Roman.$trModule2 = GHC.Types.TrNameS "main"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+Roman.$trModule3 = GHC.Types.TrNameS Roman.$trModule4
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+Roman.$trModule2 :: GHC.Prim.Addr#
+[GblId,
+ Caf=NoCafRefs,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+Roman.$trModule2 = "Roman"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0}
 Roman.$trModule1 :: GHC.Types.TrName
@@ -17,8 +33,8 @@ Roman.$trModule1 :: GHC.Types.TrName
  Caf=NoCafRefs,
  Str=m1,
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 40 20}]
-Roman.$trModule1 = GHC.Types.TrNameS "Roman"#
+         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
+Roman.$trModule1 = GHC.Types.TrNameS Roman.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0}
 Roman.$trModule :: GHC.Types.Module
@@ -28,16 +44,18 @@ Roman.$trModule :: GHC.Types.Module
  Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 30}]
 Roman.$trModule =
-  GHC.Types.Module Roman.$trModule2 Roman.$trModule1
+  GHC.Types.Module Roman.$trModule3 Roman.$trModule1
+
+-- RHS size: {terms: 1, types: 0, coercions: 0}
+lvl :: GHC.Prim.Addr#
+[GblId, Caf=NoCafRefs]
+lvl = "spec-inline.hs:(19,5)-(29,25)|function go"#
 
 -- RHS size: {terms: 2, types: 2, coercions: 0}
 Roman.foo3 :: Int
 [GblId, Str=x]
 Roman.foo3 =
-  Control.Exception.Base.patError
-    @ 'GHC.Types.LiftedRep
-    @ Int
-    "spec-inline.hs:(19,5)-(29,25)|function go"#
+  Control.Exception.Base.patError @ 'GHC.Types.LiftedRep @ Int lvl
 
 Rec {
 -- RHS size: {terms: 55, types: 9, coercions: 0}
diff --git a/testsuite/tests/simplCore/should_compile/str-rules.hs b/testsuite/tests/simplCore/should_compile/str-rules.hs
new file mode 100644
index 0000000000..a94df9958c
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/str-rules.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE MagicHash #-}
+import GHC.CString (unpackFoldrCString#, unpackCString#)
+import GHC.Base (eqString)
+main :: IO ()
+main = do
+  let mix c n = fromEnum c + n
+  n <- readLn
+
+  print $
+    -- We expect the two literals to be concatenated, resulting in "@@@ ab"
+    unpackFoldrCString# "@@@ a"# mix
+      (unpackFoldrCString# "b"# mix n)
+
+  if eqString (unpackCString# "x"#) (unpackCString# "y"#)
+    then putStrLn $ unpackCString# "@@@ c"# -- this should be optimized out
+    else putStrLn $ unpackCString# "@@@ d"#
+
+  if eqString (unpackCString# "foo"#) (unpackCString# "foo"#)
+    then putStrLn $ unpackCString# "@@@ e"#
+    else putStrLn $ unpackCString# "@@@ f"# -- this should be optimized out
diff --git a/testsuite/tests/simplCore/should_compile/str-rules.stdout b/testsuite/tests/simplCore/should_compile/str-rules.stdout
new file mode 100644
index 0000000000..a3f3ae899d
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/str-rules.stdout
@@ -0,0 +1,3 @@
+"@@@ ab"#
+"@@@ d"#
+"@@@ e"#