module SPARC.CodeGen.Base (




import GhcPrelude

import SPARC.Instr
import SPARC.Cond
import SPARC.AddrMode
import SPARC.Regs
import Format
import Reg

import GHC.Platform.Regs
import DynFlags
import Cmm
import PprCmmExpr () -- For Outputable instances
import GHC.Platform

import Outputable
import OrdList

-- | 'InstrBlock's are the insn sequences generated by the insn selectors.
--      They are really trees of insns to facilitate fast appending, where a
--      left-to-right traversal yields the insns in the correct order.
type InstrBlock
        = OrdList Instr

-- | Condition codes passed up the tree.
data CondCode
        = CondCode Bool Cond InstrBlock

-- | a.k.a "Register64"
--      Reg is the lower 32-bit temporary which contains the result.
--      Use getHiVRegFromLo to find the other VRegUnique.
--      Rules of this simplified insn selection game are therefore that
--      the returned Reg may be modified
data ChildCode64
   = ChildCode64

-- | Holds code that references a memory address.
data Amode
        = Amode
                -- the AddrMode we can use in the instruction
                --      that does the real load\/store.

                -- other setup code we have to run first before we can use the
                --      above AddrMode.

-- | Code to produce a result into a register.
--      If the result must go in a specific register, it comes out as Fixed.
--      Otherwise, the parent can decide which register to put it in.
data Register
        = Fixed Format Reg InstrBlock
        | Any   Format (Reg -> InstrBlock)

-- | Change the format field in a Register.
        :: Register -> Format -> Register

setFormatOfRegister reg format
 = case reg of
        Fixed _ reg code        -> Fixed format reg code
        Any _ codefn            -> Any   format codefn

-- | Grab the Reg for a CmmReg
getRegisterReg :: Platform -> CmmReg -> Reg

getRegisterReg _ (CmmLocal (LocalReg u pk))
        = RegVirtual $ mkVirtualReg u (cmmTypeFormat pk)

getRegisterReg platform (CmmGlobal mid)
  = case globalRegMaybe platform mid of
        Just reg -> RegReal reg
        Nothing  -> pprPanic
                        "SPARC.CodeGen.Base.getRegisterReg: global is in memory"
                        (ppr $ CmmGlobal mid)

-- Expand CmmRegOff.  ToDo: should we do it this way around, or convert
-- CmmExprs into CmmRegOff?
mangleIndexTree :: DynFlags -> CmmExpr -> CmmExpr

mangleIndexTree dflags (CmmRegOff reg off)
        = CmmMachOp (MO_Add width) [CmmReg reg, CmmLit (CmmInt (fromIntegral off) width)]
        where width = typeWidth (cmmRegType dflags reg)

mangleIndexTree _ _
        = panic "SPARC.CodeGen.Base.mangleIndexTree: no match"