Merge branch 'wip/T14951' into wip/T14068wip/T14068

8 files changed, 22 insertions, 41 deletions

diff --git a/compiler/codeGen/CgUtils.hs b/compiler/codeGen/CgUtils.hs
index c20f1fd1d0..6a2840294a 100644
--- a/compiler/codeGen/CgUtils.hs
+++ b/compiler/codeGen/CgUtils.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, GADTs #-}
+{-# LANGUAGE GADTs #-}
 
 -----------------------------------------------------------------------------
 --
@@ -10,8 +10,6 @@
 
 module CgUtils ( fixStgRegisters ) where
 
-#include "HsVersions.h"
-
 import GhcPrelude
 
 import CodeGen.Platform
diff --git a/compiler/codeGen/StgCmmBind.hs b/compiler/codeGen/StgCmmBind.hs
index 9ef552d336..b29394da6f 100644
--- a/compiler/codeGen/StgCmmBind.hs
+++ b/compiler/codeGen/StgCmmBind.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE CPP #-}
-
 -----------------------------------------------------------------------------
 --
 -- Stg to C-- code generation: bindings
@@ -15,8 +13,6 @@ module StgCmmBind (
         pushUpdateFrame, emitUpdateFrame
   ) where
 
-#include "HsVersions.h"
-
 import GhcPrelude hiding ((<*>))
 
 import StgCmmExpr
diff --git a/compiler/codeGen/StgCmmExpr.hs b/compiler/codeGen/StgCmmExpr.hs
index 3fcc935121..22fcfaf412 100644
--- a/compiler/codeGen/StgCmmExpr.hs
+++ b/compiler/codeGen/StgCmmExpr.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE CPP #-}
-{-# OPTIONS_GHC -fno-warn-unused-do-bind #-}
 
 -----------------------------------------------------------------------------
 --
@@ -61,7 +60,8 @@ cgExpr  :: StgExpr -> FCode ReturnKind
 
 cgExpr (StgApp fun args)     = cgIdApp fun args
 
-{- seq# a s ==> a -}
+-- seq# a s ==> a
+-- See Note [seq# magic] in PrelRules
 cgExpr (StgOpApp (StgPrimOp SeqOp) [StgVarArg a, _] _res_ty) =
   cgIdApp a []
 
@@ -409,7 +409,8 @@ cgCase (StgApp v []) bndr alt_type@(PrimAlt _) alts
        ; v_info <- getCgIdInfo v
        ; emitAssign (CmmLocal (idToReg dflags (NonVoid bndr)))
                     (idInfoToAmode v_info)
-       ; bindArgToReg (NonVoid bndr)
+       -- Add bndr to the environment
+       ; _ <- bindArgToReg (NonVoid bndr)
        ; cgAlts (NoGcInAlts,AssignedDirectly) (NonVoid bndr) alt_type alts }
   where
     reps_compatible = ((==) `on` (primRepSlot . idPrimRep)) v bndr
@@ -435,7 +436,8 @@ it would be better to invoke some kind of panic function here.
 cgCase scrut@(StgApp v []) _ (PrimAlt _) _
   = do { dflags <- getDynFlags
        ; mb_cc <- maybeSaveCostCentre True
-       ; withSequel (AssignTo [idToReg dflags (NonVoid v)] False) (cgExpr scrut)
+       ; _ <- withSequel
+                  (AssignTo [idToReg dflags (NonVoid v)] False) (cgExpr scrut)
        ; restoreCurrentCostCentre mb_cc
        ; emitComment $ mkFastString "should be unreachable code"
        ; l <- newBlockId
@@ -446,13 +448,14 @@ cgCase scrut@(StgApp v []) _ (PrimAlt _) _
 
 {- Note [Handle seq#]
 ~~~~~~~~~~~~~~~~~~~~~
-case seq# a s of v
-  (# s', a' #) -> e
+See Note [seq# magic] in PrelRules.
+The special case for seq# in cgCase does this:
 
+  case seq# a s of v
+    (# s', a' #) -> e
 ==>
-
-case a of v
-  (# s', a' #) -> e
+  case a of v
+    (# s', a' #) -> e
 
 (taking advantage of the fact that the return convention for (# State#, a #)
 is the same as the return convention for just 'a')
@@ -460,6 +463,7 @@ is the same as the return convention for just 'a')
 
 cgCase (StgOpApp (StgPrimOp SeqOp) [StgVarArg a, _] _) bndr alt_type alts
   = -- Note [Handle seq#]
+    -- And see Note [seq# magic] in PrelRules
     -- Use the same return convention as vanilla 'a'.
     cgCase (StgApp a []) bndr alt_type alts
 
diff --git a/compiler/codeGen/StgCmmForeign.hs b/compiler/codeGen/StgCmmForeign.hs
index d0ad17f59b..c1103e7d77 100644
--- a/compiler/codeGen/StgCmmForeign.hs
+++ b/compiler/codeGen/StgCmmForeign.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE CPP #-}
-
 -----------------------------------------------------------------------------
 --
 -- Code generation for foreign calls.
@@ -20,8 +18,6 @@ module StgCmmForeign (
   emitCloseNursery,
  ) where
 
-#include "HsVersions.h"
-
 import GhcPrelude hiding( succ, (<*>) )
 
 import StgSyn
@@ -408,8 +404,8 @@ Opening the nursery corresponds to the following code:
 @
    tso = CurrentTSO;
    cn = CurrentNursery;
-   bdfree = CurrentNuresry->free;
-   bdstart = CurrentNuresry->start;
+   bdfree = CurrentNursery->free;
+   bdstart = CurrentNursery->start;
 
    // We *add* the currently occupied portion of the nursery block to
    // the allocation limit, because we will subtract it again in
diff --git a/compiler/codeGen/StgCmmHeap.hs b/compiler/codeGen/StgCmmHeap.hs
index 07633ed4ae..3be35b35fa 100644
--- a/compiler/codeGen/StgCmmHeap.hs
+++ b/compiler/codeGen/StgCmmHeap.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE CPP #-}
-
 -----------------------------------------------------------------------------
 --
 -- Stg to C--: heap management functions
@@ -22,8 +20,6 @@ module StgCmmHeap (
         emitSetDynHdr
     ) where
 
-#include "HsVersions.h"
-
 import GhcPrelude hiding ((<*>))
 
 import StgSyn
diff --git a/compiler/codeGen/StgCmmMonad.hs b/compiler/codeGen/StgCmmMonad.hs
index 7c3864296c..cc941a2e57 100644
--- a/compiler/codeGen/StgCmmMonad.hs
+++ b/compiler/codeGen/StgCmmMonad.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, GADTs, UnboxedTuples #-}
+{-# LANGUAGE GADTs, UnboxedTuples #-}
 
 -----------------------------------------------------------------------------
 --
@@ -58,8 +58,6 @@ module StgCmmMonad (
         CgInfoDownwards(..), CgState(..)        -- non-abstract
     ) where
 
-#include "HsVersions.h"
-
 import GhcPrelude hiding( sequence, succ )
 
 import Cmm
@@ -79,6 +77,7 @@ import Unique
 import UniqSupply
 import FastString
 import Outputable
+import Util
 
 import Control.Monad
 import Data.List
@@ -696,11 +695,9 @@ emitLabel id = do tscope <- getTickScope
                   emitCgStmt (CgLabel id tscope)
 
 emitComment :: FastString -> FCode ()
-#if 0 /* def DEBUG */
-emitComment s = emitCgStmt (CgStmt (CmmComment s))
-#else
-emitComment _ = return ()
-#endif
+emitComment s
+  | debugIsOn = emitCgStmt (CgStmt (CmmComment s))
+  | otherwise = return ()
 
 emitTick :: CmmTickish -> FCode ()
 emitTick = emitCgStmt . CgStmt . CmmTick
diff --git a/compiler/codeGen/StgCmmProf.hs b/compiler/codeGen/StgCmmProf.hs
index a0bca5d661..15c31ca59c 100644
--- a/compiler/codeGen/StgCmmProf.hs
+++ b/compiler/codeGen/StgCmmProf.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE CPP #-}
-
 -----------------------------------------------------------------------------
 --
 -- Code generation for profiling
@@ -25,8 +23,6 @@ module StgCmmProf (
         ldvEnter, ldvEnterClosure, ldvRecordCreate
   ) where
 
-#include "HsVersions.h"
-
 import GhcPrelude
 
 import StgCmmClosure
diff --git a/compiler/codeGen/StgCmmTicky.hs b/compiler/codeGen/StgCmmTicky.hs
index a7d158ce3a..8f3074856a 100644
--- a/compiler/codeGen/StgCmmTicky.hs
+++ b/compiler/codeGen/StgCmmTicky.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE BangPatterns, CPP #-}
+{-# LANGUAGE BangPatterns #-}
 
 -----------------------------------------------------------------------------
 --
@@ -104,8 +104,6 @@ module StgCmmTicky (
   tickySlowCall, tickySlowCallPat,
   ) where
 
-#include "HsVersions.h"
-
 import GhcPrelude
 
 import StgCmmArgRep    ( slowCallPattern , toArgRep , argRepString )