Join points

This major patch implements Join Points, as described in
https://ghc.haskell.org/trac/ghc/wiki/SequentCore.  You have
to read that page, and especially the paper it links to, to
understand what's going on; but it is very cool.

It's Luke Maurer's work, but done in close collaboration with Simon PJ.

This Phab is a squash-merge of wip/join-points branch of
http://github.com/lukemaurer/ghc. There are many, many interdependent
changes.

Reviewers: goldfire, mpickering, bgamari, simonmar, dfeuer, austin

Subscribers: simonpj, dfeuer, mpickering, Mikolaj, thomie

Differential Revision: https://phabricator.haskell.org/D2853

1 files changed, 15 insertions, 14 deletions

diff --git a/testsuite/tests/simplCore/should_compile/spec-inline.stderr b/testsuite/tests/simplCore/should_compile/spec-inline.stderr
index 0de46d181d..dda28c8926 100644
--- a/testsuite/tests/simplCore/should_compile/spec-inline.stderr
+++ b/testsuite/tests/simplCore/should_compile/spec-inline.stderr
@@ -1,8 +1,9 @@
 
 ==================== Tidy Core ====================
-Result size of Tidy Core = {terms: 178, types: 68, coercions: 0}
+Result size of Tidy Core
+  = {terms: 178, types: 68, coercions: 0, joins: 0/2}
 
--- RHS size: {terms: 1, types: 0, coercions: 0}
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 Roman.$trModule4 :: GHC.Prim.Addr#
 [GblId,
  Caf=NoCafRefs,
@@ -10,7 +11,7 @@ Roman.$trModule4 :: GHC.Prim.Addr#
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
 Roman.$trModule4 = "main"#
 
--- RHS size: {terms: 2, types: 0, coercions: 0}
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 Roman.$trModule3 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
@@ -19,7 +20,7 @@ Roman.$trModule3 :: GHC.Types.TrName
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
 Roman.$trModule3 = GHC.Types.TrNameS Roman.$trModule4
 
--- RHS size: {terms: 1, types: 0, coercions: 0}
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 Roman.$trModule2 :: GHC.Prim.Addr#
 [GblId,
  Caf=NoCafRefs,
@@ -27,7 +28,7 @@ Roman.$trModule2 :: GHC.Prim.Addr#
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
 Roman.$trModule2 = "Roman"#
 
--- RHS size: {terms: 2, types: 0, coercions: 0}
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 Roman.$trModule1 :: GHC.Types.TrName
 [GblId,
  Caf=NoCafRefs,
@@ -36,7 +37,7 @@ Roman.$trModule1 :: GHC.Types.TrName
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
 Roman.$trModule1 = GHC.Types.TrNameS Roman.$trModule2
 
--- RHS size: {terms: 3, types: 0, coercions: 0}
+-- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
 Roman.$trModule :: GHC.Types.Module
 [GblId,
  Caf=NoCafRefs,
@@ -46,19 +47,19 @@ Roman.$trModule :: GHC.Types.Module
 Roman.$trModule =
   GHC.Types.Module Roman.$trModule3 Roman.$trModule1
 
--- RHS size: {terms: 1, types: 0, coercions: 0}
+-- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 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}
+-- RHS size: {terms: 2, types: 2, coercions: 0, joins: 0/0}
 Roman.foo3 :: Int
 [GblId, Str=x]
 Roman.foo3 =
   Control.Exception.Base.patError @ 'GHC.Types.LiftedRep @ Int lvl
 
 Rec {
--- RHS size: {terms: 55, types: 9, coercions: 0}
+-- RHS size: {terms: 55, types: 9, coercions: 0, joins: 0/1}
 Roman.foo_$s$wgo [Occ=LoopBreaker]
   :: GHC.Prim.Int# -> GHC.Prim.Int# -> GHC.Prim.Int#
 [GblId, Arity=2, Caf=NoCafRefs, Str=<S,U><S,U>]
@@ -88,7 +89,7 @@ Roman.foo_$s$wgo =
     }
 end Rec }
 
--- RHS size: {terms: 74, types: 22, coercions: 0}
+-- RHS size: {terms: 74, types: 22, coercions: 0, joins: 0/1}
 Roman.$wgo [InlPrag=[0]] :: Maybe Int -> Maybe Int -> GHC.Prim.Int#
 [GblId,
  Arity=2,
@@ -132,7 +133,7 @@ Roman.$wgo =
         }
     }
 
--- RHS size: {terms: 9, types: 5, coercions: 0}
+-- RHS size: {terms: 9, types: 5, coercions: 0, joins: 0/0}
 Roman.foo_go [InlPrag=INLINE[0]] :: Maybe Int -> Maybe Int -> Int
 [GblId,
  Arity=2,
@@ -146,7 +147,7 @@ Roman.foo_go =
   \ (w :: Maybe Int) (w1 :: Maybe Int) ->
     case Roman.$wgo w w1 of ww { __DEFAULT -> GHC.Types.I# ww }
 
--- RHS size: {terms: 2, types: 0, coercions: 0}
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 Roman.foo2 :: Int
 [GblId,
  Caf=NoCafRefs,
@@ -155,7 +156,7 @@ Roman.foo2 :: Int
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
 Roman.foo2 = GHC.Types.I# 6#
 
--- RHS size: {terms: 2, types: 1, coercions: 0}
+-- RHS size: {terms: 2, types: 1, coercions: 0, joins: 0/0}
 Roman.foo1 :: Maybe Int
 [GblId,
  Caf=NoCafRefs,
@@ -164,7 +165,7 @@ Roman.foo1 :: Maybe Int
          WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 20}]
 Roman.foo1 = GHC.Base.Just @ Int Roman.foo2
 
--- RHS size: {terms: 11, types: 4, coercions: 0}
+-- RHS size: {terms: 11, types: 4, coercions: 0, joins: 0/0}
 foo :: Int -> Int
 [GblId,
  Arity=1,