Produce new-style Cmm from the Cmm parser

The main change here is that the Cmm parser now allows high-level cmm
code with argument-passing and function calls.  For example:

foo ( gcptr a, bits32 b )
{
  if (b > 0) {
     // we can make tail calls passing arguments:
     jump stg_ap_0_fast(a);
  }

  return (x,y);
}

More details on the new cmm syntax are in Note [Syntax of .cmm files]
in CmmParse.y.

The old syntax is still more-or-less supported for those occasional
code fragments that really need to explicitly manipulate the stack.
However there are a couple of differences: it is now obligatory to
give a list of live GlobalRegs on every jump, e.g.

  jump %ENTRY_CODE(Sp(0)) [R1];

Again, more details in Note [Syntax of .cmm files].

I have rewritten most of the .cmm files in the RTS into the new
syntax, except for AutoApply.cmm which is generated by the genapply
program: this file could be generated in the new syntax instead and
would probably be better off for it, but I ran out of enthusiasm.

Some other changes in this batch:

 - The PrimOp calling convention is gone, primops now use the ordinary
   NativeNodeCall convention.  This means that primops and "foreign
   import prim" code must be written in high-level cmm, but they can
   now take more than 10 arguments.

 - CmmSink now does constant-folding (should fix #7219)

 - .cmm files now go through the cmmPipeline, and as a result we
   generate better code in many cases.  All the object files generated
   for the RTS .cmm files are now smaller.  Performance should be
   better too, but I haven't measured it yet.

 - RET_DYN frames are removed from the RTS, lots of code goes away

 - we now have some more canned GC points to cover unboxed-tuples with
   2-4 pointers, which will reduce code size a little.

1 files changed, 9 insertions, 35 deletions

diff --git a/compiler/codeGen/StgCmmLayout.hs b/compiler/codeGen/StgCmmLayout.hs
index 75d8d1c38f..4742332107 100644
--- a/compiler/codeGen/StgCmmLayout.hs
+++ b/compiler/codeGen/StgCmmLayout.hs
@@ -111,7 +111,7 @@ emitCall convs fun args
 --
 emitCallWithExtraStack
    :: (Convention, Convention) -> CmmExpr -> [CmmExpr]
-   -> (ByteOff, [(CmmExpr,ByteOff)]) -> FCode ReturnKind
+   -> [CmmExpr] -> FCode ReturnKind
 emitCallWithExtraStack (callConv, retConv) fun args extra_stack
   = do	{ dflags <- getDynFlags
         ; adjustHpBackwards
@@ -124,7 +124,7 @@ emitCallWithExtraStack (callConv, retConv) fun args extra_stack
             AssignTo res_regs _ -> do
               k <- newLabelC
               let area = Young k
-                  (off, copyin) = copyInOflow dflags retConv area res_regs
+                  (off, copyin) = copyInOflow dflags retConv area res_regs []
                   copyout = mkCallReturnsTo dflags fun callConv args k off updfr_off
                                    extra_stack
               emit (copyout <*> mkLabel k <*> copyin)
@@ -222,7 +222,7 @@ direct_call caller call_conv lbl arity args
        emitCallWithExtraStack (call_conv, NativeReturn)
                               target
                               (nonVArgs fast_args)
-                              (mkStkOffsets dflags (stack_args dflags))
+                              (nonVArgs (stack_args dflags))
   where
     target = CmmLit (CmmLabel lbl)
     (fast_args, rest_args) = splitAt real_arity args
@@ -326,32 +326,7 @@ slowCallPattern []		      = (fsLit "stg_ap_0", 0)
 
 
 -------------------------------------------------------------------------
--- Fix the byte-offsets of a bunch of things to push on the stack
-
--- This is used for pushing slow-call continuations.
--- See Note [over-saturated calls].
-
-mkStkOffsets
-  :: DynFlags
-  -> [(ArgRep, Maybe CmmExpr)]    -- things to make offsets for
-  -> ( ByteOff                    -- OUTPUTS: Topmost allocated word
-     , [(CmmExpr, ByteOff)] )     -- things with offsets (voids filtered out)
-mkStkOffsets dflags things
-    = loop 0 [] (reverse things)
-  where
-    loop offset offs [] = (offset,offs)
-    loop offset offs ((_,Nothing):things) = loop offset offs things
-	-- ignore Void arguments
-    loop offset offs ((rep,Just thing):things)
-        = loop thing_off ((thing, thing_off):offs) things
-	where
-          thing_off = offset + argRepSizeW dflags rep * wORD_SIZE dflags
-	    -- offset of thing is offset+size, because we're 
-	    -- growing the stack *downwards* as the offsets increase.
-
-
--------------------------------------------------------------------------
---	Classifying arguments: ArgRep
+--      Classifying arguments: ArgRep
 -------------------------------------------------------------------------
 
 -- ArgRep is not exported (even abstractly)
@@ -472,7 +447,7 @@ mkArgDescr _nm args
        let arg_bits = argBits dflags arg_reps
            arg_reps = filter isNonV (map idArgRep args)
            -- Getting rid of voids eases matching of standard patterns
-       case stdPattern dflags arg_reps of
+       case stdPattern arg_reps of
            Just spec_id -> return (ArgSpec spec_id)
            Nothing      -> return (ArgGen arg_bits)
 
@@ -483,10 +458,9 @@ argBits dflags (arg : args) = take (argRepSizeW dflags arg) (repeat True)
                     ++ argBits dflags args
 
 ----------------------
-stdPattern :: DynFlags -> [ArgRep] -> Maybe StgHalfWord
-stdPattern dflags reps
-  = fmap (toStgHalfWord dflags)
-  $ case reps of
+stdPattern :: [ArgRep] -> Maybe Int
+stdPattern reps
+  = case reps of
 	[]  -> Just ARG_NONE	-- just void args, probably
 	[N] -> Just ARG_N
 	[P] -> Just ARG_P
@@ -545,7 +519,7 @@ emitClosureProcAndInfoTable top_lvl bndr lf_info info_tbl args body
         ; let args' = if node_points then (node : arg_regs) else arg_regs
               conv  = if nodeMustPointToIt dflags lf_info then NativeNodeCall
                                                           else NativeDirectCall
-              (offset, _) = mkCallEntry dflags conv args'
+              (offset, _) = mkCallEntry dflags conv args' []
         ; emitClosureAndInfoTable info_tbl conv args' $ body (offset, node, arg_regs)
         }