X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FcodeGen%2FCgUtils.hs;h=c8cae4b6cf056cb866d37355444ebe1b040a53dc;hb=90334ab3c0c841d466671a416763989d169d4877;hp=414e90a91adf290ad230576199d306c1709f8418;hpb=a609df425d10b6d5e87cf43d01b4c2cd83551fbb;p=ghc-hetmet.git

diff --git a/ghc/compiler/codeGen/CgUtils.hs b/ghc/compiler/codeGen/CgUtils.hs
index 414e90a..c8cae4b 100644
--- a/ghc/compiler/codeGen/CgUtils.hs
+++ b/ghc/compiler/codeGen/CgUtils.hs
@@ -52,7 +52,7 @@ import CLabel		( CLabel, mkStringLitLabel )
 import Digraph		( SCC(..), stronglyConnComp )
 import ListSetOps	( assocDefault )
 import Util		( filterOut, sortLe )
-import CmdLineOpts	( DynFlags )
+import CmdLineOpts	( DynFlags(..), HscTarget(..) )
 import FastString	( LitString, FastString, unpackFS )
 import Outputable
 
@@ -60,9 +60,6 @@ import Char		( ord )
 import DATA_BITS
 import Maybe		( isNothing )
 
-#include "../includes/ghcconfig.h"
-	-- For WORDS_BIGENDIAN
-
 -------------------------------------------------------------------------
 --
 --	Random small functions
@@ -299,7 +296,12 @@ emitDataLits lbl lits
 emitRODataLits :: CLabel -> [CmmLit] -> Code
 -- Emit a read-only data block
 emitRODataLits lbl lits
-  = emitData ReadOnlyData (CmmDataLabel lbl : map CmmStaticLit lits)
+  = emitData section (CmmDataLabel lbl : map CmmStaticLit lits)
+  where section | any needsRelocation lits = RelocatableReadOnlyData
+                | otherwise                = ReadOnlyData
+        needsRelocation (CmmLabel _)      = True
+        needsRelocation (CmmLabelOff _ _) = True
+        needsRelocation _                 = False
 
 mkStringCLit :: String -> FCode CmmLit
 -- Make a global definition for the string,
@@ -356,8 +358,12 @@ emitSwitch tag_expr branches mb_deflt lo_tag hi_tag
 		  Nothing    -> return Nothing
 		  Just stmts -> do id <- forkCgStmts stmts; return (Just id)
 
+	; dflags <- getDynFlags
+	; let via_C | HscC <- hscTarget dflags = True
+		    | otherwise                = False
+
 	; stmts <- mk_switch tag_expr (sortLe le branches) 
-			mb_deflt_id lo_tag hi_tag
+			mb_deflt_id lo_tag hi_tag via_C
 	; emitCgStmts stmts
 	}
   where
@@ -365,17 +371,17 @@ emitSwitch tag_expr branches mb_deflt lo_tag hi_tag
 
 
 mk_switch :: CmmExpr -> [(ConTagZ, CgStmts)]
-	  -> Maybe BlockId -> ConTagZ -> ConTagZ
+	  -> Maybe BlockId -> ConTagZ -> ConTagZ -> Bool
 	  -> FCode CgStmts
 
 -- SINGLETON TAG RANGE: no case analysis to do
-mk_switch tag_expr [(tag,stmts)] _ lo_tag hi_tag
+mk_switch tag_expr [(tag,stmts)] _ lo_tag hi_tag via_C
   | lo_tag == hi_tag
   = ASSERT( tag == lo_tag )
     return stmts
 
 -- SINGLETON BRANCH, NO DEFUALT: no case analysis to do
-mk_switch tag_expr [(tag,stmts)] Nothing lo_tag hi_tag
+mk_switch tag_expr [(tag,stmts)] Nothing lo_tag hi_tag via_C
   = return stmts
 	-- The simplifier might have eliminated a case
 	-- 	 so we may have e.g. case xs of 
@@ -384,7 +390,7 @@ mk_switch tag_expr [(tag,stmts)] Nothing lo_tag hi_tag
 	-- can't happen, so no need to test
 
 -- SINGLETON BRANCH: one equality check to do
-mk_switch tag_expr [(tag,stmts)] (Just deflt) lo_tag hi_tag
+mk_switch tag_expr [(tag,stmts)] (Just deflt) lo_tag hi_tag via_C
   = return (CmmCondBranch cond deflt `consCgStmt` stmts)
   where
     cond  =  cmmNeWord tag_expr (CmmLit (mkIntCLit tag))
@@ -395,9 +401,17 @@ mk_switch tag_expr [(tag,stmts)] (Just deflt) lo_tag hi_tag
 -- the branches is the tag 0, because comparing '== 0' is likely to be
 -- more efficient than other kinds of comparison.
 
--- DENSE TAG RANGE: use a switch statment
-mk_switch tag_expr branches mb_deflt lo_tag hi_tag
-  | use_switch 	-- Use a switch
+-- DENSE TAG RANGE: use a switch statment.
+--
+-- We also use a switch uncoditionally when compiling via C, because
+-- this will get emitted as a C switch statement and the C compiler
+-- should do a good job of optimising it.  Also, older GCC versions
+-- (2.95 in particular) have problems compiling the complicated
+-- if-trees generated by this code, so compiling to a switch every
+-- time works around that problem.
+--
+mk_switch tag_expr branches mb_deflt lo_tag hi_tag via_C
+  | use_switch || via_C 	-- Use a switch
   = do	{ branch_ids <- mapM forkCgStmts (map snd branches)
 	; let 
 		tagged_blk_ids = zip (map fst branches) (map Just branch_ids)
@@ -421,7 +435,8 @@ mk_switch tag_expr branches mb_deflt lo_tag hi_tag
   = do { (assign_tag, tag_expr') <- assignTemp' tag_expr
        ; let cond = cmmULtWord tag_expr' (CmmLit (mkIntCLit lowest_branch))
 	     branch = CmmCondBranch cond deflt
-       ; stmts <- mk_switch tag_expr' branches mb_deflt lowest_branch hi_tag
+       ; stmts <- mk_switch tag_expr' branches mb_deflt 
+			lowest_branch hi_tag via_C
        ; return (assign_tag `consCgStmt` (branch `consCgStmt` stmts))
        }
 
@@ -429,15 +444,18 @@ mk_switch tag_expr branches mb_deflt lo_tag hi_tag
   = do { (assign_tag, tag_expr') <- assignTemp' tag_expr
        ; let cond = cmmUGtWord tag_expr' (CmmLit (mkIntCLit highest_branch))
 	     branch = CmmCondBranch cond deflt
-       ; stmts <- mk_switch tag_expr' branches mb_deflt lo_tag highest_branch
+       ; stmts <- mk_switch tag_expr' branches mb_deflt 
+			lo_tag highest_branch via_C
        ; return (assign_tag `consCgStmt` (branch `consCgStmt` stmts))
        }
 
   | otherwise	-- Use an if-tree
   = do	{ (assign_tag, tag_expr') <- assignTemp' tag_expr
 		-- To avoid duplication
-	; lo_stmts <- mk_switch tag_expr' lo_branches mb_deflt lo_tag (mid_tag-1)
-	; hi_stmts <- mk_switch tag_expr' hi_branches mb_deflt mid_tag hi_tag
+	; lo_stmts <- mk_switch tag_expr' lo_branches mb_deflt 
+				lo_tag (mid_tag-1) via_C
+	; hi_stmts <- mk_switch tag_expr' hi_branches mb_deflt 
+				mid_tag hi_tag via_C
 	; lo_id <- forkCgStmts lo_stmts
 	; let cond = cmmULtWord tag_expr' (CmmLit (mkIntCLit mid_tag))
 	      branch_stmt = CmmCondBranch cond lo_id