--
-- Code generator utilities; mostly monadic
--
--- (c) The University of Glasgow 2004
+-- (c) The University of Glasgow 2004-2006
--
-----------------------------------------------------------------------------
addToMem, addToMemE,
mkWordCLit,
- mkStringCLit,
+ mkStringCLit, mkByteStringCLit,
packHalfWordsCLit,
blankWord
) where
#include "HsVersions.h"
import CgMonad
-import TyCon ( TyCon, tyConName )
-import Id ( Id )
-import Constants ( wORD_SIZE )
-import SMRep ( CgRep, StgWord, hALF_WORD_SIZE_IN_BITS, ByteOff,
- WordOff, idCgRep )
+import TyCon
+import Id
+import Constants
+import SMRep
import PprCmm ( {- instances -} )
import Cmm
import CLabel
import CmmUtils
-import MachOp ( MachRep(..), wordRep, MachOp(..), MachHint(..),
- mo_wordOr, mo_wordAnd, mo_wordNe, mo_wordEq,
- mo_wordULt, mo_wordUGt, mo_wordUGe, machRepByteWidth )
-import ForeignCall ( CCallConv(..) )
-import Literal ( Literal(..) )
-import CLabel ( CLabel, mkStringLitLabel )
-import Digraph ( SCC(..), stronglyConnComp )
-import ListSetOps ( assocDefault )
-import Util ( filterOut, sortLe )
-import DynFlags ( DynFlags(..), HscTarget(..) )
-import Packages ( HomeModules )
-import FastString ( LitString, FastString, bytesFS )
+import MachOp
+import ForeignCall
+import Literal
+import Digraph
+import ListSetOps
+import Util
+import DynFlags
+import FastString
+import PackageConfig
import Outputable
-import Char ( ord )
-import DATA_BITS
-import DATA_WORD ( Word8 )
-import Maybe ( isNothing )
+import Data.Char
+import Data.Bits
+import Data.Word
+import Data.Maybe
-------------------------------------------------------------------------
--
--
-------------------------------------------------------------------------
-tagToClosure :: HomeModules -> TyCon -> CmmExpr -> CmmExpr
-tagToClosure hmods tycon tag
+tagToClosure :: PackageId -> TyCon -> CmmExpr -> CmmExpr
+tagToClosure this_pkg tycon tag
= CmmLoad (cmmOffsetExprW closure_tbl tag) wordRep
where closure_tbl = CmmLit (CmmLabel lbl)
- lbl = mkClosureTableLabel hmods (tyConName tycon)
+ lbl = mkClosureTableLabel this_pkg (tyConName tycon)
-------------------------------------------------------------------------
--
where
use_switch = {- pprTrace "mk_switch" (
ppr tag_expr <+> text "n_tags:" <+> int n_tags <+>
+ text "branches:" <+> ppr (map fst branches) <+>
text "n_branches:" <+> int n_branches <+>
- text "lo_tag: " <+> int lo_tag <+>
- text "hi_tag: " <+> int hi_tag <+>
- text "real_lo_tag: " <+> int real_lo_tag <+>
- text "real_hi_tag: " <+> int real_hi_tag) $ -}
+ text "lo_tag:" <+> int lo_tag <+>
+ text "hi_tag:" <+> int hi_tag <+>
+ text "real_lo_tag:" <+> int real_lo_tag <+>
+ text "real_hi_tag:" <+> int real_hi_tag) $ -}
ASSERT( n_branches > 1 && n_tags > 1 )
- n_tags > 2 && (small || dense || via_C)
- -- a 2-branch switch always turns into an if.
- small = n_tags <= 4
+ n_tags > 2 && (via_C || (dense && big_enough))
+ -- up to 4 branches we use a decision tree, otherwise
+ -- a switch (== jump table in the NCG). This seems to be
+ -- optimal, and corresponds with what gcc does.
+ big_enough = n_branches > 4
dense = n_branches > (n_tags `div` 2)
- exhaustive = n_tags == n_branches
n_branches = length branches
-- ignore default slots at each end of the range if there's