path: root/compiler/nativeGen/PPC/Ppr.hs

-----------------------------------------------------------------------------
--
-- Pretty-printing assembly language
--
-- (c) The University of Glasgow 1993-2005
--
-----------------------------------------------------------------------------

{-# OPTIONS -fno-warn-tabs #-}
-- The above warning supression flag is a temporary kludge.
-- While working on this module you are encouraged to remove it and
-- detab the module (please do the detabbing in a separate patch). See
--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
-- for details

module PPC.Ppr (
	pprNatCmmDecl,
	pprBasicBlock,
	pprSectionHeader,
	pprData,
	pprInstr,
	pprSize,
	pprImm,
	pprDataItem,
)

where

import PPC.Regs
import PPC.Instr
import PPC.Cond
import PprBase
import Instruction
import Size
import Reg
import RegClass
import TargetReg

import OldCmm

import CLabel

import Unique		( pprUnique, Uniquable(..) )
import Platform
import Pretty
import FastString
import qualified Outputable
import Outputable ( PlatformOutputable, panic )

import Data.Word
import Data.Bits


-- -----------------------------------------------------------------------------
-- Printing this stuff out

pprNatCmmDecl :: Platform -> NatCmmDecl CmmStatics Instr -> Doc
pprNatCmmDecl platform (CmmData section dats) =
  pprSectionHeader platform section $$ pprDatas platform dats

 -- special case for split markers:
pprNatCmmDecl platform (CmmProc Nothing lbl (ListGraph []))
    = pprLabel platform lbl

 -- special case for code without an info table:
pprNatCmmDecl platform (CmmProc Nothing lbl (ListGraph blocks)) =
  pprSectionHeader platform Text $$
  pprLabel platform lbl $$ -- blocks guaranteed not null, so label needed
  vcat (map (pprBasicBlock platform) blocks)

pprNatCmmDecl platform (CmmProc (Just (Statics info_lbl info)) _entry_lbl (ListGraph blocks)) =
  pprSectionHeader platform Text $$
  (
       (if platformHasSubsectionsViaSymbols platform
        then pprCLabel_asm platform (mkDeadStripPreventer info_lbl) <> char ':'
        else empty) $$
       vcat (map (pprData platform) info) $$
       pprLabel platform info_lbl
  ) $$
  vcat (map (pprBasicBlock platform) blocks) $$
     -- above: Even the first block gets a label, because with branch-chain
     -- elimination, it might be the target of a goto.
        (if platformHasSubsectionsViaSymbols platform
         then
         -- If we are using the .subsections_via_symbols directive
         -- (available on recent versions of Darwin),
         -- we have to make sure that there is some kind of reference
         -- from the entry code to a label on the _top_ of of the info table,
         -- so that the linker will not think it is unreferenced and dead-strip
         -- it. That's why the label is called a DeadStripPreventer (_dsp).
                  text "\t.long "
              <+> pprCLabel_asm platform info_lbl
              <+> char '-'
              <+> pprCLabel_asm platform (mkDeadStripPreventer info_lbl)
         else empty)


pprBasicBlock :: Platform -> NatBasicBlock Instr -> Doc
pprBasicBlock platform (BasicBlock blockid instrs) =
  pprLabel platform (mkAsmTempLabel (getUnique blockid)) $$
  vcat (map (pprInstr platform) instrs)



pprDatas :: Platform -> CmmStatics -> Doc
pprDatas platform (Statics lbl dats) = vcat (pprLabel platform lbl : map (pprData platform) dats)

pprData :: Platform -> CmmStatic -> Doc
pprData _ (CmmString str)          = pprASCII str
pprData platform (CmmUninitialised bytes) = ptext (sLit keyword) <> int bytes
    where keyword = case platformOS platform of
                    OSDarwin -> ".space "
                    _        -> ".skip "
pprData platform (CmmStaticLit lit)       = pprDataItem platform lit

pprGloblDecl :: Platform -> CLabel -> Doc
pprGloblDecl platform lbl
  | not (externallyVisibleCLabel lbl) = empty
  | otherwise = ptext (sLit ".globl ") <> pprCLabel_asm platform lbl

pprTypeAndSizeDecl :: Platform -> CLabel -> Doc
pprTypeAndSizeDecl platform lbl
  | platformOS platform == OSLinux && externallyVisibleCLabel lbl
    = ptext (sLit ".type ") <>
      pprCLabel_asm platform lbl <> ptext (sLit ", @object")
pprTypeAndSizeDecl _ _
  = empty

pprLabel :: Platform -> CLabel -> Doc
pprLabel platform lbl = pprGloblDecl platform lbl
                     $$ pprTypeAndSizeDecl platform lbl
                     $$ (pprCLabel_asm platform lbl <> char ':')


pprASCII :: [Word8] -> Doc
pprASCII str
  = vcat (map do1 str) $$ do1 0
    where
       do1 :: Word8 -> Doc
       do1 w = ptext (sLit "\t.byte\t") <> int (fromIntegral w)


-- -----------------------------------------------------------------------------
-- pprInstr: print an 'Instr'

instance PlatformOutputable Instr where
    pprPlatform platform instr = Outputable.docToSDoc $ pprInstr platform instr


pprReg :: Platform -> Reg -> Doc

pprReg platform r
  = case r of
      RegReal    (RealRegSingle i) -> ppr_reg_no i
      RegReal    (RealRegPair{})   -> panic "PPC.pprReg: no reg pairs on this arch"
      RegVirtual (VirtualRegI  u)  -> text "%vI_" <> asmSDoc (pprUnique u)
      RegVirtual (VirtualRegHi u)  -> text "%vHi_" <> asmSDoc (pprUnique u)
      RegVirtual (VirtualRegF  u)  -> text "%vF_" <> asmSDoc (pprUnique u)
      RegVirtual (VirtualRegD  u)  -> text "%vD_" <> asmSDoc (pprUnique u)
      RegVirtual (VirtualRegSSE  u) -> text "%vSSE_" <> asmSDoc (pprUnique u)
  where
    ppr_reg_no :: Int -> Doc
    ppr_reg_no i =
        case platformOS platform of
        OSDarwin ->
            ptext
                (case i of {
                 0 -> sLit "r0";   1 -> sLit "r1";
                 2 -> sLit "r2";   3 -> sLit "r3";
                 4 -> sLit "r4";   5 -> sLit "r5";
                 6 -> sLit "r6";   7 -> sLit "r7";
                 8 -> sLit "r8";   9 -> sLit "r9";
                10 -> sLit "r10";  11 -> sLit "r11";
                12 -> sLit "r12";  13 -> sLit "r13";
                14 -> sLit "r14";  15 -> sLit "r15";
                16 -> sLit "r16";  17 -> sLit "r17";
                18 -> sLit "r18";  19 -> sLit "r19";
                20 -> sLit "r20";  21 -> sLit "r21";
                22 -> sLit "r22";  23 -> sLit "r23";
                24 -> sLit "r24";  25 -> sLit "r25";
                26 -> sLit "r26";  27 -> sLit "r27";
                28 -> sLit "r28";  29 -> sLit "r29";
                30 -> sLit "r30";  31 -> sLit "r31";
                32 -> sLit "f0";  33 -> sLit "f1";
                34 -> sLit "f2";  35 -> sLit "f3";
                36 -> sLit "f4";  37 -> sLit "f5";
                38 -> sLit "f6";  39 -> sLit "f7";
                40 -> sLit "f8";  41 -> sLit "f9";
                42 -> sLit "f10"; 43 -> sLit "f11";
                44 -> sLit "f12"; 45 -> sLit "f13";
                46 -> sLit "f14"; 47 -> sLit "f15";
                48 -> sLit "f16"; 49 -> sLit "f17";
                50 -> sLit "f18"; 51 -> sLit "f19";
                52 -> sLit "f20"; 53 -> sLit "f21";
                54 -> sLit "f22"; 55 -> sLit "f23";
                56 -> sLit "f24"; 57 -> sLit "f25";
                58 -> sLit "f26"; 59 -> sLit "f27";
                60 -> sLit "f28"; 61 -> sLit "f29";
                62 -> sLit "f30"; 63 -> sLit "f31";
                _  -> sLit "very naughty powerpc register"
              })
        _
         | i <= 31   -> int i      -- GPRs
         | i <= 63   -> int (i-32) -- FPRs
         | otherwise -> ptext (sLit "very naughty powerpc register")



pprSize :: Size -> Doc
pprSize x 
 = ptext (case x of
		II8	-> sLit "b"
	        II16	-> sLit "h"
		II32	-> sLit "w"
		FF32	-> sLit "fs"
		FF64	-> sLit "fd"
		_	-> panic "PPC.Ppr.pprSize: no match")
		
		
pprCond :: Cond -> Doc
pprCond c 
 = ptext (case c of {
		ALWAYS  -> sLit "";
		EQQ	-> sLit "eq";	NE    -> sLit "ne";
		LTT     -> sLit "lt";  GE    -> sLit "ge";
		GTT     -> sLit "gt";  LE    -> sLit "le";
		LU      -> sLit "lt";  GEU   -> sLit "ge";
		GU      -> sLit "gt";  LEU   -> sLit "le"; })


pprImm :: Platform -> Imm -> Doc

pprImm _        (ImmInt i)     = int i
pprImm _        (ImmInteger i) = integer i
pprImm platform (ImmCLbl l)    = pprCLabel_asm platform l
pprImm platform (ImmIndex l i) = pprCLabel_asm platform l <> char '+' <> int i
pprImm _        (ImmLit s)     = s

pprImm _        (ImmFloat _)  = ptext (sLit "naughty float immediate")
pprImm _        (ImmDouble _) = ptext (sLit "naughty double immediate")

pprImm platform (ImmConstantSum a b) = pprImm platform a <> char '+' <> pprImm platform b
pprImm platform (ImmConstantDiff a b) = pprImm platform a <> char '-'
                            <> lparen <> pprImm platform b <> rparen

pprImm platform (LO i)
  = if platformOS platform == OSDarwin
    then hcat [ text "lo16(", pprImm platform i, rparen ]
    else pprImm platform i <> text "@l"

pprImm platform (HI i)
  = if platformOS platform == OSDarwin
    then hcat [ text "hi16(", pprImm platform i, rparen ]
    else pprImm platform i <> text "@h"

pprImm platform (HA i)
  = if platformOS platform == OSDarwin
    then hcat [ text "ha16(", pprImm platform i, rparen ]
    else pprImm platform i <> text "@ha"


pprAddr :: Platform -> AddrMode -> Doc
pprAddr platform (AddrRegReg r1 r2)
  = pprReg platform r1 <+> ptext (sLit ", ") <+> pprReg platform r2

pprAddr platform (AddrRegImm r1 (ImmInt i)) = hcat [ int i, char '(', pprReg platform r1, char ')' ]
pprAddr platform (AddrRegImm r1 (ImmInteger i)) = hcat [ integer i, char '(', pprReg platform r1, char ')' ]
pprAddr platform (AddrRegImm r1 imm) = hcat [ pprImm platform imm, char '(', pprReg platform r1, char ')' ]


pprSectionHeader :: Platform -> Section -> Doc
pprSectionHeader platform seg
 = case seg of
        Text                    -> ptext (sLit ".text\n.align 2")
        Data                    -> ptext (sLit ".data\n.align 2")
        ReadOnlyData
         | osDarwin             -> ptext (sLit ".const\n.align 2")
         | otherwise            -> ptext (sLit ".section .rodata\n\t.align 2")
        RelocatableReadOnlyData
         | osDarwin             -> ptext (sLit ".const_data\n.align 2")
         | otherwise            -> ptext (sLit ".data\n\t.align 2")
        UninitialisedData
         | osDarwin             -> ptext (sLit ".const_data\n.align 2")
         | otherwise            -> ptext (sLit ".section .bss\n\t.align 2")
        ReadOnlyData16
         | osDarwin             -> ptext (sLit ".const\n.align 4")
         | otherwise            -> ptext (sLit ".section .rodata\n\t.align 4")
        OtherSection _          ->
            panic "PprMach.pprSectionHeader: unknown section"
    where osDarwin = platformOS platform == OSDarwin


pprDataItem :: Platform -> CmmLit -> Doc
pprDataItem platform lit
  = vcat (ppr_item (cmmTypeSize $ cmmLitType lit) lit)
    where
	imm = litToImm lit

	ppr_item II8   _ = [ptext (sLit "\t.byte\t") <> pprImm platform imm]

	ppr_item II32  _ = [ptext (sLit "\t.long\t") <> pprImm platform imm]

	ppr_item FF32 (CmmFloat r _)
           = let bs = floatToBytes (fromRational r)
             in  map (\b -> ptext (sLit "\t.byte\t") <> pprImm platform (ImmInt b)) bs

    	ppr_item FF64 (CmmFloat r _)
           = let bs = doubleToBytes (fromRational r)
             in  map (\b -> ptext (sLit "\t.byte\t") <> pprImm platform (ImmInt b)) bs

	ppr_item II16 _	= [ptext (sLit "\t.short\t") <> pprImm platform imm]

        ppr_item II64 (CmmInt x _)  =
                [ptext (sLit "\t.long\t")
                    <> int (fromIntegral 
                        (fromIntegral (x `shiftR` 32) :: Word32)),
                 ptext (sLit "\t.long\t")
                    <> int (fromIntegral (fromIntegral x :: Word32))]

	ppr_item _ _
		= panic "PPC.Ppr.pprDataItem: no match"


pprInstr :: Platform -> Instr -> Doc

pprInstr _ (COMMENT _) = empty -- nuke 'em
{-
pprInstr platform (COMMENT s) =
     if platformOS platform == OSLinux
     then ptext (sLit "# ") <> ftext s
     else ptext (sLit "; ") <> ftext s
-}
pprInstr platform (DELTA d)
   = pprInstr platform (COMMENT (mkFastString ("\tdelta = " ++ show d)))

pprInstr _ (NEWBLOCK _)
   = panic "PprMach.pprInstr: NEWBLOCK"

pprInstr _ (LDATA _ _)
   = panic "PprMach.pprInstr: LDATA"

{-
pprInstr _ (SPILL reg slot)
   = hcat [
   	ptext (sLit "\tSPILL"),
	char '\t',
	pprReg platform reg,
	comma,
	ptext (sLit "SLOT") <> parens (int slot)]

pprInstr _ (RELOAD slot reg)
   = hcat [
   	ptext (sLit "\tRELOAD"),
	char '\t',
	ptext (sLit "SLOT") <> parens (int slot),
	comma,
	pprReg platform reg]
-}

pprInstr platform (LD sz reg addr) = hcat [
	char '\t',
	ptext (sLit "l"),
	ptext (case sz of
	    II8  -> sLit "bz"
	    II16 -> sLit "hz"
	    II32 -> sLit "wz"
	    FF32 -> sLit "fs"
	    FF64 -> sLit "fd"
	    _	 -> panic "PPC.Ppr.pprInstr: no match"
	    ),
        case addr of AddrRegImm _ _ -> empty
                     AddrRegReg _ _ -> char 'x',
	char '\t',
	pprReg platform reg,
	ptext (sLit ", "),
	pprAddr platform addr
    ]
pprInstr platform (LA sz reg addr) = hcat [
	char '\t',
	ptext (sLit "l"),
	ptext (case sz of
	    II8  -> sLit "ba"
	    II16 -> sLit "ha"
	    II32 -> sLit "wa"
	    FF32 -> sLit "fs"
	    FF64 -> sLit "fd"
	    _	 -> panic "PPC.Ppr.pprInstr: no match"
	    ),
        case addr of AddrRegImm _ _ -> empty
                     AddrRegReg _ _ -> char 'x',
	char '\t',
	pprReg platform reg,
	ptext (sLit ", "),
	pprAddr platform addr
    ]
pprInstr platform (ST sz reg addr) = hcat [
	char '\t',
	ptext (sLit "st"),
	pprSize sz,
        case addr of AddrRegImm _ _ -> empty
                     AddrRegReg _ _ -> char 'x',
	char '\t',
	pprReg platform reg,
	ptext (sLit ", "),
	pprAddr platform addr
    ]
pprInstr platform (STU sz reg addr) = hcat [
	char '\t',
	ptext (sLit "st"),
	pprSize sz,
	ptext (sLit "u\t"),
        case addr of AddrRegImm _ _ -> empty
                     AddrRegReg _ _ -> char 'x',
	pprReg platform reg,
	ptext (sLit ", "),
	pprAddr platform addr
    ]
pprInstr platform (LIS reg imm) = hcat [
	char '\t',
	ptext (sLit "lis"),
	char '\t',
	pprReg platform reg,
	ptext (sLit ", "),
	pprImm platform imm
    ]
pprInstr platform (LI reg imm) = hcat [
	char '\t',
	ptext (sLit "li"),
	char '\t',
	pprReg platform reg,
	ptext (sLit ", "),
	pprImm platform imm
    ]
pprInstr platform (MR reg1 reg2) 
    | reg1 == reg2 = empty
    | otherwise = hcat [
	char '\t',
	case targetClassOfReg platform reg1 of
	    RcInteger -> ptext (sLit "mr")
	    _ -> ptext (sLit "fmr"),
	char '\t',
	pprReg platform reg1,
	ptext (sLit ", "),
	pprReg platform reg2
    ]
pprInstr platform (CMP sz reg ri) = hcat [
	char '\t',
	op,
	char '\t',
	pprReg platform reg,
	ptext (sLit ", "),
	pprRI platform ri
    ]
    where
	op = hcat [
		ptext (sLit "cmp"),
		pprSize sz,
		case ri of
		    RIReg _ -> empty
		    RIImm _ -> char 'i'
	    ]
pprInstr platform (CMPL sz reg ri) = hcat [
	char '\t',
	op,
	char '\t',
	pprReg platform reg,
	ptext (sLit ", "),
	pprRI platform ri
    ]
    where
	op = hcat [
		ptext (sLit "cmpl"),
		pprSize sz,
		case ri of
		    RIReg _ -> empty
		    RIImm _ -> char 'i'
	    ]
pprInstr platform (BCC cond blockid) = hcat [
	char '\t',
	ptext (sLit "b"),
	pprCond cond,
	char '\t',
	pprCLabel_asm platform lbl
    ]
    where lbl = mkAsmTempLabel (getUnique blockid)

pprInstr platform (BCCFAR cond blockid) = vcat [
        hcat [
            ptext (sLit "\tb"),
            pprCond (condNegate cond),
            ptext (sLit "\t$+8")
        ],
        hcat [
            ptext (sLit "\tb\t"),
            pprCLabel_asm platform lbl
        ]
    ]
    where lbl = mkAsmTempLabel (getUnique blockid)

pprInstr platform (JMP lbl) = hcat [ -- an alias for b that takes a CLabel
	char '\t',
	ptext (sLit "b"),
	char '\t',
	pprCLabel_asm platform lbl
    ]

pprInstr platform (MTCTR reg) = hcat [
	char '\t',
	ptext (sLit "mtctr"),
	char '\t',
	pprReg platform reg
    ]
pprInstr _ (BCTR _ _) = hcat [
	char '\t',
	ptext (sLit "bctr")
    ]
pprInstr platform (BL lbl _) = hcat [
	ptext (sLit "\tbl\t"),
        pprCLabel_asm platform lbl
    ]
pprInstr _ (BCTRL _) = hcat [
	char '\t',
	ptext (sLit "bctrl")
    ]
pprInstr platform (ADD reg1 reg2 ri) = pprLogic platform (sLit "add") reg1 reg2 ri
pprInstr platform (ADDIS reg1 reg2 imm) = hcat [
	char '\t',
	ptext (sLit "addis"),
	char '\t',
	pprReg platform reg1,
	ptext (sLit ", "),
	pprReg platform reg2,
	ptext (sLit ", "),
	pprImm platform imm
    ]

pprInstr platform (ADDC reg1 reg2 reg3) = pprLogic platform (sLit "addc") reg1 reg2 (RIReg reg3)
pprInstr platform (ADDE reg1 reg2 reg3) = pprLogic platform (sLit "adde") reg1 reg2 (RIReg reg3)
pprInstr platform (SUBF reg1 reg2 reg3) = pprLogic platform (sLit "subf") reg1 reg2 (RIReg reg3)
pprInstr platform (MULLW reg1 reg2 ri@(RIReg _)) = pprLogic platform (sLit "mullw") reg1 reg2 ri
pprInstr platform (MULLW reg1 reg2 ri@(RIImm _)) = pprLogic platform (sLit "mull") reg1 reg2 ri
pprInstr platform (DIVW reg1 reg2 reg3) = pprLogic platform (sLit "divw") reg1 reg2 (RIReg reg3)
pprInstr platform (DIVWU reg1 reg2 reg3) = pprLogic platform (sLit "divwu") reg1 reg2 (RIReg reg3)

pprInstr platform (MULLW_MayOflo reg1 reg2 reg3) = vcat [
         hcat [ ptext (sLit "\tmullwo\t"), pprReg platform reg1, ptext (sLit ", "),
                                          pprReg platform reg2, ptext (sLit ", "),
                                          pprReg platform reg3 ],
         hcat [ ptext (sLit "\tmfxer\t"),  pprReg platform reg1 ],
         hcat [ ptext (sLit "\trlwinm\t"), pprReg platform reg1, ptext (sLit ", "),
                                          pprReg platform reg1, ptext (sLit ", "),
                                          ptext (sLit "2, 31, 31") ]
    ]

    	-- for some reason, "andi" doesn't exist.
	-- we'll use "andi." instead.
pprInstr platform (AND reg1 reg2 (RIImm imm)) = hcat [
	char '\t',
	ptext (sLit "andi."),
	char '\t',
	pprReg platform reg1,
	ptext (sLit ", "),
	pprReg platform reg2,
	ptext (sLit ", "),
	pprImm platform imm
    ]
pprInstr platform (AND reg1 reg2 ri) = pprLogic platform (sLit "and") reg1 reg2 ri

pprInstr platform (OR reg1 reg2 ri) = pprLogic platform (sLit "or") reg1 reg2 ri
pprInstr platform (XOR reg1 reg2 ri) = pprLogic platform (sLit "xor") reg1 reg2 ri

pprInstr platform (XORIS reg1 reg2 imm) = hcat [
	char '\t',
	ptext (sLit "xoris"),
	char '\t',
	pprReg platform reg1,
	ptext (sLit ", "),
	pprReg platform reg2,
	ptext (sLit ", "),
	pprImm platform imm
    ]

pprInstr platform (EXTS sz reg1 reg2) = hcat [
	char '\t',
	ptext (sLit "exts"),
	pprSize sz,
	char '\t',
	pprReg platform reg1,
	ptext (sLit ", "),
	pprReg platform reg2
    ]

pprInstr platform (NEG reg1 reg2) = pprUnary platform (sLit "neg") reg1 reg2
pprInstr platform (NOT reg1 reg2) = pprUnary platform (sLit "not") reg1 reg2

pprInstr platform (SLW reg1 reg2 ri) = pprLogic platform (sLit "slw") reg1 reg2 (limitShiftRI ri)
pprInstr platform (SRW reg1 reg2 ri) = pprLogic platform (sLit "srw") reg1 reg2 (limitShiftRI ri)
pprInstr platform (SRAW reg1 reg2 ri) = pprLogic platform (sLit "sraw") reg1 reg2 (limitShiftRI ri)
pprInstr platform (RLWINM reg1 reg2 sh mb me) = hcat [
        ptext (sLit "\trlwinm\t"),
        pprReg platform reg1,
        ptext (sLit ", "),
        pprReg platform reg2,
        ptext (sLit ", "),
        int sh,
        ptext (sLit ", "),
        int mb,
        ptext (sLit ", "),
        int me
    ]
    
pprInstr platform (FADD sz reg1 reg2 reg3) = pprBinaryF platform (sLit "fadd") sz reg1 reg2 reg3
pprInstr platform (FSUB sz reg1 reg2 reg3) = pprBinaryF platform (sLit "fsub") sz reg1 reg2 reg3
pprInstr platform (FMUL sz reg1 reg2 reg3) = pprBinaryF platform (sLit "fmul") sz reg1 reg2 reg3
pprInstr platform (FDIV sz reg1 reg2 reg3) = pprBinaryF platform (sLit "fdiv") sz reg1 reg2 reg3
pprInstr platform (FNEG reg1 reg2) = pprUnary platform (sLit "fneg") reg1 reg2

pprInstr platform (FCMP reg1 reg2) = hcat [
	char '\t',
	ptext (sLit "fcmpu\tcr0, "),
	    -- Note: we're using fcmpu, not fcmpo
	    -- The difference is with fcmpo, compare with NaN is an invalid operation.
	    -- We don't handle invalid fp ops, so we don't care
	pprReg platform reg1,
	ptext (sLit ", "),
	pprReg platform reg2
    ]

pprInstr platform (FCTIWZ reg1 reg2) = pprUnary platform (sLit "fctiwz") reg1 reg2
pprInstr platform (FRSP reg1 reg2) = pprUnary platform (sLit "frsp") reg1 reg2

pprInstr _ (CRNOR dst src1 src2) = hcat [
        ptext (sLit "\tcrnor\t"),
        int dst,
        ptext (sLit ", "),
        int src1,
        ptext (sLit ", "),
        int src2
    ]

pprInstr platform (MFCR reg) = hcat [
	char '\t',
	ptext (sLit "mfcr"),
	char '\t',
	pprReg platform reg
    ]

pprInstr platform (MFLR reg) = hcat [
	char '\t',
	ptext (sLit "mflr"),
	char '\t',
	pprReg platform reg
    ]

pprInstr platform (FETCHPC reg) = vcat [
        ptext (sLit "\tbcl\t20,31,1f"),
        hcat [ ptext (sLit "1:\tmflr\t"), pprReg platform reg ]
    ]

pprInstr _ LWSYNC = ptext (sLit "\tlwsync")

-- pprInstr _ _ = panic "pprInstr (ppc)"


pprLogic :: Platform -> LitString -> Reg -> Reg -> RI -> Doc
pprLogic platform op reg1 reg2 ri = hcat [
	char '\t',
	ptext op,
	case ri of
	    RIReg _ -> empty
	    RIImm _ -> char 'i',
	char '\t',
	pprReg platform reg1,
	ptext (sLit ", "),
	pprReg platform reg2,
	ptext (sLit ", "),
	pprRI platform ri
    ]


pprUnary :: Platform -> LitString -> Reg -> Reg -> Doc
pprUnary platform op reg1 reg2 = hcat [
	char '\t',
	ptext op,
	char '\t',
	pprReg platform reg1,
	ptext (sLit ", "),
	pprReg platform reg2
    ]
    
    
pprBinaryF :: Platform -> LitString -> Size -> Reg -> Reg -> Reg -> Doc
pprBinaryF platform op sz reg1 reg2 reg3 = hcat [
	char '\t',
	ptext op,
	pprFSize sz,
	char '\t',
	pprReg platform reg1,
	ptext (sLit ", "),
	pprReg platform reg2,
	ptext (sLit ", "),
	pprReg platform reg3
    ]
    
pprRI :: Platform -> RI -> Doc
pprRI platform (RIReg r) = pprReg platform r
pprRI platform (RIImm r) = pprImm platform r


pprFSize :: Size -> Doc
pprFSize FF64	= empty
pprFSize FF32	= char 's'
pprFSize _	= panic "PPC.Ppr.pprFSize: no match"

    -- limit immediate argument for shift instruction to range 0..32
    -- (yes, the maximum is really 32, not 31)
limitShiftRI :: RI -> RI
limitShiftRI (RIImm (ImmInt i)) | i > 32 || i < 0 = RIImm (ImmInt 32)
limitShiftRI x = x