Cmm jumps always have live register information.

Jumps now always have live register information attached, so drop Maybes.

compiler/cmm/CmmCvt.hs

@@ -109,7 +109,7 @@ ofZgraph g = Old.ListGraph $ mapMaybe convert_block $ postorderDfs g
                               | otherwise -> [Old.CmmCondBranch expr tid, Old.CmmBranch fid]
                             CmmSwitch arg ids -> [Old.CmmSwitch arg ids]
                             -- ToDo: STG Live
-                            CmmCall e _ r _ _ _ -> [Old.CmmJump e (Just r)]
+                            CmmCall e _ r _ _ _ -> [Old.CmmJump e r]
                             CmmForeignCall {} -> panic "ofZgraph: CmmForeignCall"
                           tail_of bid = case foldBlockNodesB3 (first, middle, last) block () of
                                           Old.BasicBlock _ stmts -> stmts

compiler/cmm/OldCmm.hs

@@ -156,7 +156,7 @@ data CmmStmt
 
   | CmmJump                       -- Jump to another C-- function,
       CmmExpr                       -- Target
-      (Maybe [GlobalReg])           -- Live registers at call site;
+      [GlobalReg]                   -- Live registers at call site;
                                     --      Nothing -> no information, assume
                                     --                 all live
                                     --      Just .. -> info on liveness, []

compiler/cmm/OldPprCmm.hs

@@ -161,7 +161,7 @@ genCondBranch expr ident =
 --
 --     jump foo(a, b, c);
 --
-genJump :: CmmExpr -> Maybe [GlobalReg] -> SDoc
+genJump :: CmmExpr -> [GlobalReg] -> SDoc
 genJump expr live =
     hcat [ ptext (sLit "jump")
          , space
@@ -171,7 +171,7 @@ genJump expr live =
                     CmmLoad (CmmReg _) _ -> pprExpr expr
                     _                    -> parens (pprExpr expr)
          , semi <+> ptext (sLit "// ")
-         , maybe empty ppr live]
+         , ppr live]
 
 -- --------------------------------------------------------------------------
 -- Return from a function. [1], Section 6.8.2 of version 1.128

compiler/llvmGen/LlvmCodeGen/CodeGen.hs

@@ -510,7 +510,7 @@ cmmPrimOpFunctions env mop
                           ++ " not supported here")
 
 -- | Tail function calls
-genJump :: LlvmEnv -> CmmExpr -> Maybe [GlobalReg] -> UniqSM StmtData
+genJump :: LlvmEnv -> CmmExpr -> [GlobalReg] -> UniqSM StmtData
 
 -- Call to known function
 genJump env (CmmLit (CmmLabel lbl)) live = do
@@ -1258,10 +1258,10 @@ funPrologue dflags = concat $ map getReg $ activeStgRegs platform
 
 -- | Function epilogue. Load STG variables to use as argument for call.
 -- STG Liveness optimisation done here.
-funEpilogue :: LlvmEnv -> Maybe [GlobalReg] -> UniqSM ([LlvmVar], LlvmStatements)
+funEpilogue :: LlvmEnv -> [GlobalReg] -> UniqSM ([LlvmVar], LlvmStatements)
 
 -- Have information and liveness optimisation is enabled
-funEpilogue env (Just live) | gopt Opt_RegLiveness dflags = do
+funEpilogue env live | gopt Opt_RegLiveness dflags = do
     loads <- mapM loadExpr (activeStgRegs platform)
     let (vars, stmts) = unzip loads
     return (vars, concatOL stmts)

compiler/nativeGen/X86/CodeGen.hs

@@ -173,9 +173,8 @@ stmtToInstrs stmt = do
       panic "stmtToInstrs: return statement should have been cps'd away"
 
 
-jumpRegs :: DynFlags -> Maybe [GlobalReg] -> [Reg]
-jumpRegs dflags Nothing      = allHaskellArgRegs dflags
-jumpRegs dflags (Just gregs) = [ RegReal r | Just r <- map (globalRegMaybe platform) gregs ]
+jumpRegs :: DynFlags -> [GlobalReg] -> [Reg]
+jumpRegs dflags gregs = [ RegReal r | Just r <- map (globalRegMaybe platform) gregs ]
     where platform = targetPlatform dflags
 
 --------------------------------------------------------------------------------