Give manifestSP better information about the actual SP location.

This patch fixes silliness where the SP pointer is continually
bumped up and down.
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>

compiler/cmm/CmmCPS.hs

@@ -112,12 +112,13 @@ cpsTop hsc_env (CmmProc h@(TopInfo {stack_info=StackInfo {arg_space=entry_off}})
 
        --------------- Stack layout ----------------
        slotEnv <- run $ liveSlotAnal g
+       let spEntryMap = getSpEntryMap entry_off g
        mbpprTrace "live slot analysis results: " (ppr slotEnv) $ return ()
-       let areaMap = layout procPoints slotEnv entry_off g
+       let areaMap = layout procPoints spEntryMap slotEnv entry_off g
        mbpprTrace "areaMap" (ppr areaMap) $ return ()
 
        ------------  Manifest the stack pointer --------
-       g  <- run $ manifestSP areaMap entry_off g
+       g  <- run $ manifestSP spEntryMap areaMap entry_off g
        dump Opt_D_dump_cmmz "after manifestSP" g
        -- UGH... manifestSP can require updates to the procPointMap.
        -- We can probably do something quicker here for the update...

compiler/cmm/CmmProcPoint.hs

@@ -378,6 +378,8 @@ add_CopyOuts protos procPoints g = foldGraphBlocks mb_copy_out (return mapEmpty)
 -- 4. build info tables for the procedures -- and update the info table for
 --    the SRTs in the entry procedure as well.
 -- Input invariant: A block should only be reachable from a single ProcPoint.
+-- ToDo: use the _ret naming convention that the old code generator
+-- used. -- EZY
 splitAtProcPoints :: CLabel -> ProcPointSet-> ProcPointSet -> BlockEnv Status ->
                      CmmTop -> FuelUniqSM [CmmTop]
 splitAtProcPoints entry_label callPPs procPoints procMap