    module SPARC.CodeGen.Amode (
            getAmode
    )

    where

    import GhcPrelude

    import {-# SOURCE #-} SPARC.CodeGen.Gen32
    import SPARC.CodeGen.Base
    import SPARC.AddrMode
    import SPARC.Imm
    import SPARC.Instr
    import SPARC.Regs
    import SPARC.Base
    import NCGMonad
    import Format

    import Cmm

    import OrdList

    -- | Generate code to reference a memory address.
    getAmode
            :: CmmExpr      -- ^ expr producing an address
            -> NatM Amode

    getAmode tree@(CmmRegOff _ _)
        = do dflags <- getDynFlags
             getAmode (mangleIndexTree dflags tree)

    getAmode (CmmMachOp (MO_Sub _) [x, CmmLit (CmmInt i _)])
      | fits13Bits (-i)
      = do
           (reg, code) <- getSomeReg x
           let
             off  = ImmInt (-(fromInteger i))
           return (Amode (AddrRegImm reg off) code)

    getAmode (CmmMachOp (MO_Add _) [x, CmmLit (CmmInt i _)])
      | fits13Bits i
      = do
           (reg, code) <- getSomeReg x
           let
             off  = ImmInt (fromInteger i)
           return (Amode (AddrRegImm reg off) code)

    getAmode (CmmMachOp (MO_Add _) [x, y])
      = do
        (regX, codeX) <- getSomeReg x
        (regY, codeY) <- getSomeReg y
        let
            code = codeX `appOL` codeY
        return (Amode (AddrRegReg regX regY) code)

    getAmode (CmmLit lit)
      = do
            let imm__2      = litToImm lit
            tmp1    <- getNewRegNat II32
            tmp2    <- getNewRegNat II32

            let code = toOL [ SETHI (HI imm__2) tmp1
                            , OR    False tmp1 (RIImm (LO imm__2)) tmp2]

            return (Amode (AddrRegReg tmp2 g0) code)

    getAmode other
      = do
           (reg, code) <- getSomeReg other
           let
                off  = ImmInt 0
           return (Amode (AddrRegImm reg off) code)