nativeGen/X86/Ppr.hs

    {-# LANGUAGE CPP #-}

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

    {-# OPTIONS_GHC -fno-warn-orphans #-}
    module X86.Ppr (
            pprNatCmmDecl,
            pprData,
            pprInstr,
            pprFormat,
            pprImm,
            pprDataItem,
    )

    where

    #include "HsVersions.h"
    #include "nativeGen/NCG.h"

    import X86.Regs
    import X86.Instr
    import X86.Cond
    import Instruction
    import Format
    import Reg
    import PprBase

    import Hoopl
    import BasicTypes       (Alignment)
    import DynFlags
    import Cmm              hiding (topInfoTable)
    import CLabel
    import Unique           ( pprUniqueAlways, Uniquable(..) )
    import Platform
    import FastString
    import Outputable

    import Data.Word

    import Data.Char

    import Data.Bits

    -- -----------------------------------------------------------------------------
    -- Printing this stuff out
    --
    --
    -- Note [Subsections Via Symbols]
    --
    -- 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).
    --
    -- The LLVM code gen already creates `iTableSuf` symbols, where
    -- the X86 would generate the DeadStripPreventer (_dsp) symbol.
    -- Therefore all that is left for llvm code gen, is to ensure
    -- that all the `iTableSuf` symbols are marked as used.
    -- As of this writing the documentation regarding the
    -- .subsections_via_symbols and -dead_strip can be found at
    -- <https://developer.apple.com/library/mac/documentation/DeveloperTools/Reference/Assembler/040-Assembler_Directives/asm_directives.html#//apple_ref/doc/uid/TP30000823-TPXREF101>

    pprNatCmmDecl :: NatCmmDecl (Alignment, CmmStatics) Instr -> SDoc
    pprNatCmmDecl (CmmData section dats) =
      pprSectionAlign section $$ pprDatas dats

    pprNatCmmDecl proc@(CmmProc top_info lbl _ (ListGraph blocks)) =
      sdocWithDynFlags $ \dflags ->
      case topInfoTable proc of
        Nothing ->
           case blocks of
             []     -> -- special case for split markers:
               pprLabel lbl
             blocks -> -- special case for code without info table:
               pprSectionAlign (Section Text lbl) $$
               pprLabel lbl $$ -- blocks guaranteed not null, so label needed
               vcat (map (pprBasicBlock top_info) blocks) $$
               (if debugLevel dflags > 0
                then ppr (mkAsmTempEndLabel lbl) <> char ':' else empty) $$
               pprSizeDecl lbl

        Just (Statics info_lbl _) ->
          sdocWithPlatform $ \platform ->
          pprSectionAlign (Section Text info_lbl) $$
          (if platformHasSubsectionsViaSymbols platform
              then ppr (mkDeadStripPreventer info_lbl) <> char ':'
              else empty) $$
          vcat (map (pprBasicBlock top_info) blocks) $$
          -- above: Even the first block gets a label, because with branch-chain
          -- elimination, it might be the target of a goto.
          (if platformHasSubsectionsViaSymbols platform
           then -- See Note [Subsections Via Symbols]
                    text "\t.long "
                <+> ppr info_lbl
                <+> char '-'
                <+> ppr (mkDeadStripPreventer info_lbl)
           else empty) $$
          (if debugLevel dflags > 0
           then ppr (mkAsmTempEndLabel info_lbl) <> char ':' else empty) $$
          pprSizeDecl info_lbl

    -- | Output the ELF .size directive.
    pprSizeDecl :: CLabel -> SDoc
    pprSizeDecl lbl
     = sdocWithPlatform $ \platform ->
       if osElfTarget (platformOS platform)
       then text "\t.size" <+> ppr lbl <> ptext (sLit ", .-") <> ppr lbl
       else empty

    pprBasicBlock :: LabelMap CmmStatics -> NatBasicBlock Instr -> SDoc
    pprBasicBlock info_env (BasicBlock blockid instrs)
      = sdocWithDynFlags $ \dflags ->
        maybe_infotable $$
        pprLabel asmLbl $$
        vcat (map pprInstr instrs) $$
        (if debugLevel dflags > 0
         then ppr (mkAsmTempEndLabel asmLbl) <> char ':' else empty)
      where
        asmLbl = mkAsmTempLabel (getUnique blockid)
        maybe_infotable = case mapLookup blockid info_env of
           Nothing   -> empty
           Just (Statics info_lbl info) ->
               pprAlignForSection Text $$
               infoTableLoc $$
               vcat (map pprData info) $$
               pprLabel info_lbl
        -- Make sure the info table has the right .loc for the block
        -- coming right after it. See [Note: Info Offset]
        infoTableLoc = case instrs of
          (l@LOCATION{} : _) -> pprInstr l
          _other             -> empty

    pprDatas :: (Alignment, CmmStatics) -> SDoc
    pprDatas (align, (Statics lbl dats))
     = vcat (pprAlign align : pprLabel lbl : map pprData dats)

    pprData :: CmmStatic -> SDoc
    pprData (CmmString str)
     = ptext (sLit "\t.asciz ") <> doubleQuotes (pprASCII str)

    pprData (CmmUninitialised bytes)
     = sdocWithPlatform $ \platform ->
       if platformOS platform == OSDarwin then text ".space " <> int bytes
                                          else text ".skip "  <> int bytes

    pprData (CmmStaticLit lit) = pprDataItem lit

    pprGloblDecl :: CLabel -> SDoc
    pprGloblDecl lbl
      | not (externallyVisibleCLabel lbl) = empty
      | otherwise = text ".globl " <> ppr lbl

    pprTypeAndSizeDecl :: CLabel -> SDoc
    pprTypeAndSizeDecl lbl
        = sdocWithPlatform $ \platform ->
          if osElfTarget (platformOS platform) && externallyVisibleCLabel lbl
          then text ".type " <> ppr lbl <> ptext (sLit ", @object")
          else empty

    pprLabel :: CLabel -> SDoc
    pprLabel lbl = pprGloblDecl lbl
                $$ pprTypeAndSizeDecl lbl
                $$ (ppr lbl <> char ':')

    pprASCII :: [Word8] -> SDoc
    pprASCII str
      = hcat (map (do1 . fromIntegral) str)
        where
           do1 :: Int -> SDoc
           do1 w | '\t' <- chr w = ptext (sLit "\\t")
           do1 w | '\n' <- chr w = ptext (sLit "\\n")
           do1 w | '"'  <- chr w = ptext (sLit "\\\"")
           do1 w | '\\' <- chr w = ptext (sLit "\\\\")
           do1 w | isPrint (chr w) = char (chr w)
           do1 w | otherwise = char '\\' <> octal w

           octal :: Int -> SDoc
           octal w = int ((w `div` 64) `mod` 8)
                      <> int ((w `div` 8) `mod` 8)
                      <> int (w `mod` 8)

    pprAlign :: Int -> SDoc
    pprAlign bytes
            = sdocWithPlatform $ \platform ->
              text ".align " <> int (alignment platform)
      where
            alignment platform = if platformOS platform == OSDarwin
                                 then log2 bytes
                                 else      bytes

            log2 :: Int -> Int  -- cache the common ones
            log2 1 = 0
            log2 2 = 1
            log2 4 = 2
            log2 8 = 3
            log2 n = 1 + log2 (n `quot` 2)

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

    instance Outputable Instr where
        ppr instr = pprInstr instr

    pprReg :: Format -> Reg -> SDoc
    pprReg f r
      = case r of
          RegReal    (RealRegSingle i) ->
              sdocWithPlatform $ \platform ->
              if target32Bit platform then ppr32_reg_no f i
                                      else ppr64_reg_no f i
          RegReal    (RealRegPair _ _) -> panic "X86.Ppr: no reg pairs on this arch"
          RegVirtual (VirtualRegI  u)  -> text "%vI_"   <> pprUniqueAlways u
          RegVirtual (VirtualRegHi u)  -> text "%vHi_"  <> pprUniqueAlways u
          RegVirtual (VirtualRegF  u)  -> text "%vF_"   <> pprUniqueAlways u
          RegVirtual (VirtualRegD  u)  -> text "%vD_"   <> pprUniqueAlways u
          RegVirtual (VirtualRegSSE u) -> text "%vSSE_" <> pprUniqueAlways u
      where
        ppr32_reg_no :: Format -> Int -> SDoc
        ppr32_reg_no II8   = ppr32_reg_byte
        ppr32_reg_no II16  = ppr32_reg_word
        ppr32_reg_no _     = ppr32_reg_long

        ppr32_reg_byte i = ptext
          (case i of {
             0 -> sLit "%al";     1 -> sLit "%bl";
             2 -> sLit "%cl";     3 -> sLit "%dl";
            _  -> sLit "very naughty I386 byte register"
          })

        ppr32_reg_word i = ptext
          (case i of {
             0 -> sLit "%ax";     1 -> sLit "%bx";
             2 -> sLit "%cx";     3 -> sLit "%dx";
             4 -> sLit "%si";     5 -> sLit "%di";
             6 -> sLit "%bp";     7 -> sLit "%sp";
            _  -> sLit "very naughty I386 word register"
          })

        ppr32_reg_long i = ptext
          (case i of {
             0 -> sLit "%eax";    1 -> sLit "%ebx";
             2 -> sLit "%ecx";    3 -> sLit "%edx";
             4 -> sLit "%esi";    5 -> sLit "%edi";
             6 -> sLit "%ebp";    7 -> sLit "%esp";
             _  -> ppr_reg_float i
          })

        ppr64_reg_no :: Format -> Int -> SDoc
        ppr64_reg_no II8   = ppr64_reg_byte
        ppr64_reg_no II16  = ppr64_reg_word
        ppr64_reg_no II32  = ppr64_reg_long
        ppr64_reg_no _     = ppr64_reg_quad

        ppr64_reg_byte i = ptext
          (case i of {
             0 -> sLit "%al";     1 -> sLit "%bl";
             2 -> sLit "%cl";     3 -> sLit "%dl";
             4 -> sLit "%sil";    5 -> sLit "%dil"; -- new 8-bit regs!
             6 -> sLit "%bpl";    7 -> sLit "%spl";
             8 -> sLit "%r8b";    9  -> sLit "%r9b";
            10 -> sLit "%r10b";   11 -> sLit "%r11b";
            12 -> sLit "%r12b";   13 -> sLit "%r13b";
            14 -> sLit "%r14b";   15 -> sLit "%r15b";
            _  -> sLit "very naughty x86_64 byte register"
          })

        ppr64_reg_word i = ptext
          (case i of {
             0 -> sLit "%ax";     1 -> sLit "%bx";
             2 -> sLit "%cx";     3 -> sLit "%dx";
             4 -> sLit "%si";     5 -> sLit "%di";
             6 -> sLit "%bp";     7 -> sLit "%sp";
             8 -> sLit "%r8w";    9  -> sLit "%r9w";
            10 -> sLit "%r10w";   11 -> sLit "%r11w";
            12 -> sLit "%r12w";   13 -> sLit "%r13w";
            14 -> sLit "%r14w";   15 -> sLit "%r15w";
            _  -> sLit "very naughty x86_64 word register"
          })

        ppr64_reg_long i = ptext
          (case i of {
             0 -> sLit "%eax";    1  -> sLit "%ebx";
             2 -> sLit "%ecx";    3  -> sLit "%edx";
             4 -> sLit "%esi";    5  -> sLit "%edi";
             6 -> sLit "%ebp";    7  -> sLit "%esp";
             8 -> sLit "%r8d";    9  -> sLit "%r9d";
            10 -> sLit "%r10d";   11 -> sLit "%r11d";
            12 -> sLit "%r12d";   13 -> sLit "%r13d";
            14 -> sLit "%r14d";   15 -> sLit "%r15d";
            _  -> sLit "very naughty x86_64 register"
          })

        ppr64_reg_quad i = ptext
          (case i of {
             0 -> sLit "%rax";      1 -> sLit "%rbx";
             2 -> sLit "%rcx";      3 -> sLit "%rdx";
             4 -> sLit "%rsi";      5 -> sLit "%rdi";
             6 -> sLit "%rbp";      7 -> sLit "%rsp";
             8 -> sLit "%r8";       9 -> sLit "%r9";
            10 -> sLit "%r10";    11 -> sLit "%r11";
            12 -> sLit "%r12";    13 -> sLit "%r13";
            14 -> sLit "%r14";    15 -> sLit "%r15";
            _  -> ppr_reg_float i
          })

    ppr_reg_float :: Int -> LitString
    ppr_reg_float i = case i of
            16 -> sLit "%fake0";  17 -> sLit "%fake1"
            18 -> sLit "%fake2";  19 -> sLit "%fake3"
            20 -> sLit "%fake4";  21 -> sLit "%fake5"
            24 -> sLit "%xmm0";   25 -> sLit "%xmm1"
            26 -> sLit "%xmm2";   27 -> sLit "%xmm3"
            28 -> sLit "%xmm4";   29 -> sLit "%xmm5"
            30 -> sLit "%xmm6";   31 -> sLit "%xmm7"
            32 -> sLit "%xmm8";   33 -> sLit "%xmm9"
            34 -> sLit "%xmm10";  35 -> sLit "%xmm11"
            36 -> sLit "%xmm12";  37 -> sLit "%xmm13"
            38 -> sLit "%xmm14";  39 -> sLit "%xmm15"
            _  -> sLit "very naughty x86 register"

    pprFormat :: Format -> SDoc
    pprFormat x
     = ptext (case x of
                    II8   -> sLit "b"
                    II16  -> sLit "w"
                    II32  -> sLit "l"
                    II64  -> sLit "q"
                    FF32  -> sLit "ss"      -- "scalar single-precision float" (SSE2)
                    FF64  -> sLit "sd"      -- "scalar double-precision float" (SSE2)
                    FF80  -> sLit "t"
                    )

    pprFormat_x87 :: Format -> SDoc
    pprFormat_x87 x
      = ptext $ case x of
                    FF32  -> sLit "s"
                    FF64  -> sLit "l"
                    FF80  -> sLit "t"
                    _     -> panic "X86.Ppr.pprFormat_x87"

    pprCond :: Cond -> SDoc
    pprCond c
     = ptext (case c of {
                    GEU     -> sLit "ae";   LU    -> sLit "b";
                    EQQ     -> sLit "e";    GTT   -> sLit "g";
                    GE      -> sLit "ge";   GU    -> sLit "a";
                    LTT     -> sLit "l";    LE    -> sLit "le";
                    LEU     -> sLit "be";   NE    -> sLit "ne";
                    NEG     -> sLit "s";    POS   -> sLit "ns";
                    CARRY   -> sLit "c";   OFLO  -> sLit "o";
                    PARITY  -> sLit "p";   NOTPARITY -> sLit "np";
                    ALWAYS  -> sLit "mp"})

    pprImm :: Imm -> SDoc
    pprImm (ImmInt i)     = int i
    pprImm (ImmInteger i) = integer i
    pprImm (ImmCLbl l)    = ppr l
    pprImm (ImmIndex l i) = ppr l <> char '+' <> int i
    pprImm (ImmLit s)     = s

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

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

    pprAddr :: AddrMode -> SDoc
    pprAddr (ImmAddr imm off)
      = let pp_imm = pprImm imm
        in
        if (off == 0) then
            pp_imm
        else if (off < 0) then
            pp_imm <> int off
        else
            pp_imm <> char '+' <> int off

    pprAddr (AddrBaseIndex base index displacement)
      = sdocWithPlatform $ \platform ->
        let
            pp_disp  = ppr_disp displacement
            pp_off p = pp_disp <> char '(' <> p <> char ')'
            pp_reg r = pprReg (archWordFormat (target32Bit platform)) r
        in
        case (base, index) of
          (EABaseNone,  EAIndexNone) -> pp_disp
          (EABaseReg b, EAIndexNone) -> pp_off (pp_reg b)
          (EABaseRip,   EAIndexNone) -> pp_off (text "%rip")
          (EABaseNone,  EAIndex r i) -> pp_off (comma <> pp_reg r <> comma <> int i)
          (EABaseReg b, EAIndex r i) -> pp_off (pp_reg b <> comma <> pp_reg r
                                           <> comma <> int i)
          _                         -> panic "X86.Ppr.pprAddr: no match"

      where
        ppr_disp (ImmInt 0) = empty
        ppr_disp imm        = pprImm imm

    -- | Print section header and appropriate alignment for that section.
    pprSectionAlign :: Section -> SDoc
    pprSectionAlign (Section (OtherSection _) _) =
         panic "X86.Ppr.pprSectionAlign: unknown section"
    pprSectionAlign sec@(Section seg _) =
      sdocWithPlatform $ \platform ->
        pprSectionHeader platform sec $$
        pprAlignForSection seg

    -- | Print appropriate alignment for the given section type.
    pprAlignForSection :: SectionType -> SDoc
    pprAlignForSection seg =
      sdocWithPlatform $ \platform ->
        text ".align " <>
        case platformOS platform of
          -- Darwin: alignments are given as shifts.
          OSDarwin
           | target32Bit platform ->
              case seg of
               ReadOnlyData16    -> int 4
               CString           -> int 1
               _                 -> int 2
           | otherwise ->
              case seg of
               ReadOnlyData16    -> int 4
               CString           -> int 1
               _                 -> int 3
          -- Other: alignments are given as bytes.
          _
           | target32Bit platform ->
              case seg of
               Text              -> text "4,0x90"
               ReadOnlyData16    -> int 16
               CString           -> int 1
               _                 -> int 4
           | otherwise ->
              case seg of
               ReadOnlyData16    -> int 16
               CString           -> int 1
               _                 -> int 8

    pprDataItem :: CmmLit -> SDoc
    pprDataItem lit = sdocWithDynFlags $ \dflags -> pprDataItem' dflags lit

    pprDataItem' :: DynFlags -> CmmLit -> SDoc
    pprDataItem' dflags lit
      = vcat (ppr_item (cmmTypeFormat $ cmmLitType dflags lit) lit)
        where
            platform = targetPlatform dflags
            imm = litToImm lit

            -- These seem to be common:
            ppr_item II8   _ = [text "\t.byte\t" <> pprImm imm]
            ppr_item II16  _ = [text "\t.word\t" <> pprImm imm]
            ppr_item II32  _ = [text "\t.long\t" <> pprImm imm]

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

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

            ppr_item II64 _
                = case platformOS platform of
                  OSDarwin
                   | target32Bit platform ->
                      case lit of
                      CmmInt x _ ->
                          [text "\t.long\t"
                              <> int (fromIntegral (fromIntegral x :: Word32)),
                           text "\t.long\t"
                              <> int (fromIntegral
                                  (fromIntegral (x `shiftR` 32) :: Word32))]
                      _ -> panic "X86.Ppr.ppr_item: no match for II64"
                   | otherwise ->
                      [text "\t.quad\t" <> pprImm imm]
                  _
                   | target32Bit platform ->
                      [text "\t.quad\t" <> pprImm imm]
                   | otherwise ->
                      -- x86_64: binutils can't handle the R_X86_64_PC64
                      -- relocation type, which means we can't do
                      -- pc-relative 64-bit addresses. Fortunately we're
                      -- assuming the small memory model, in which all such
                      -- offsets will fit into 32 bits, so we have to stick
                      -- to 32-bit offset fields and modify the RTS
                      -- appropriately
                      --
                      -- See Note [x86-64-relative] in includes/rts/storage/InfoTables.h
                      --
                      case lit of
                      -- A relative relocation:
                      CmmLabelDiffOff _ _ _ ->
                          [text "\t.long\t" <> pprImm imm,
                           text "\t.long\t0"]
                      _ ->
                          [text "\t.quad\t" <> pprImm imm]

            ppr_item _ _
                    = panic "X86.Ppr.ppr_item: no match"

    asmComment :: SDoc -> SDoc
    asmComment c = ifPprDebug $ text "# " <> c

    pprInstr :: Instr -> SDoc

    pprInstr (COMMENT s)
       = asmComment (ftext s)

    pprInstr (LOCATION file line col _name)
       = text "\t.loc " <> ppr file <+> ppr line <+> ppr col

    pprInstr (DELTA d)
       = asmComment $ text ("\tdelta = " ++ show d)

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

    pprInstr (UNWIND lbl d)
       = asmComment (text "\tunwind = " <> ppr d)
         $$ ppr lbl <> colon

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

    {-
    pprInstr (SPILL reg slot)
       = hcat [
            text "\tSPILL",
            char ' ',
            pprUserReg reg,
            comma,
            text "SLOT" <> parens (int slot)]

    pprInstr (RELOAD slot reg)
       = hcat [
            text "\tRELOAD",
            char ' ',
            text "SLOT" <> parens (int slot),
            comma,
            pprUserReg reg]
    -}

    -- Replace 'mov $0x0,%reg' by 'xor %reg,%reg', which is smaller and cheaper.
    -- The code generator catches most of these already, but not all.
    pprInstr (MOV format (OpImm (ImmInt 0)) dst@(OpReg _))
      = pprInstr (XOR format' dst dst)
      where format' = case format of
              II64 -> II32          -- 32-bit version is equivalent, and smaller
              _    -> format
    pprInstr (MOV format src dst)
      = pprFormatOpOp (sLit "mov") format src dst

    pprInstr (CMOV cc format src dst)
      = pprCondOpReg (sLit "cmov") format cc src dst

    pprInstr (MOVZxL II32 src dst) = pprFormatOpOp (sLit "mov") II32 src dst
            -- 32-to-64 bit zero extension on x86_64 is accomplished by a simple
            -- movl.  But we represent it as a MOVZxL instruction, because
            -- the reg alloc would tend to throw away a plain reg-to-reg
            -- move, and we still want it to do that.

    pprInstr (MOVZxL formats src dst)
      = pprFormatOpOpCoerce (sLit "movz") formats II32 src dst
            -- zero-extension only needs to extend to 32 bits: on x86_64,
            -- the remaining zero-extension to 64 bits is automatic, and the 32-bit
            -- instruction is shorter.

    pprInstr (MOVSxL formats src dst)
      = sdocWithPlatform $ \platform ->
        pprFormatOpOpCoerce (sLit "movs") formats (archWordFormat (target32Bit platform)) src dst

    -- here we do some patching, since the physical registers are only set late
    -- in the code generation.
    pprInstr (LEA format (OpAddr (AddrBaseIndex (EABaseReg reg1) (EAIndex reg2 1) (ImmInt 0))) dst@(OpReg reg3))
      | reg1 == reg3
      = pprFormatOpOp (sLit "add") format (OpReg reg2) dst

    pprInstr (LEA format (OpAddr (AddrBaseIndex (EABaseReg reg1) (EAIndex reg2 1) (ImmInt 0))) dst@(OpReg reg3))
      | reg2 == reg3
      = pprFormatOpOp (sLit "add") format (OpReg reg1) dst

    pprInstr (LEA format (OpAddr (AddrBaseIndex (EABaseReg reg1) EAIndexNone displ)) dst@(OpReg reg3))
      | reg1 == reg3
      = pprInstr (ADD format (OpImm displ) dst)

    pprInstr (LEA format src dst) = pprFormatOpOp (sLit "lea") format src dst

    pprInstr (ADD format (OpImm (ImmInt (-1))) dst)
      = pprFormatOp (sLit "dec") format dst
    pprInstr (ADD format (OpImm (ImmInt 1)) dst)
      = pprFormatOp (sLit "inc") format dst
    pprInstr (ADD format src dst) = pprFormatOpOp (sLit "add") format src dst
    pprInstr (ADC format src dst) = pprFormatOpOp (sLit "adc") format src dst
    pprInstr (SUB format src dst) = pprFormatOpOp (sLit "sub") format src dst
    pprInstr (SBB format src dst) = pprFormatOpOp (sLit "sbb") format src dst
    pprInstr (IMUL format op1 op2) = pprFormatOpOp (sLit "imul") format op1 op2

    pprInstr (ADD_CC format src dst)
      = pprFormatOpOp (sLit "add") format src dst
    pprInstr (SUB_CC format src dst)
      = pprFormatOpOp (sLit "sub") format src dst

    {- A hack.  The Intel documentation says that "The two and three
       operand forms [of IMUL] may also be used with unsigned operands
       because the lower half of the product is the same regardless if
       (sic) the operands are signed or unsigned.  The CF and OF flags,
       however, cannot be used to determine if the upper half of the
       result is non-zero."  So there.
    -}

    -- Use a 32-bit instruction when possible as it saves a byte.
    -- Notably, extracting the tag bits of a pointer has this form.
    -- TODO: we could save a byte in a subsequent CMP instruction too,
    -- but need something like a peephole pass for this
    pprInstr (AND II64 src@(OpImm (ImmInteger mask)) dst)
      | 0 <= mask && mask < 0xffffffff
        = pprInstr (AND II32 src dst)
    pprInstr (AND FF32 src dst) = pprOpOp (sLit "andps") FF32 src dst
    pprInstr (AND FF64 src dst) = pprOpOp (sLit "andpd") FF64 src dst
    pprInstr (AND format src dst) = pprFormatOpOp (sLit "and") format src dst
    pprInstr (OR  format src dst) = pprFormatOpOp (sLit "or")  format src dst

    pprInstr (XOR FF32 src dst) = pprOpOp (sLit "xorps") FF32 src dst
    pprInstr (XOR FF64 src dst) = pprOpOp (sLit "xorpd") FF64 src dst
    pprInstr (XOR format src dst) = pprFormatOpOp (sLit "xor")  format src dst

    pprInstr (POPCNT format src dst) = pprOpOp (sLit "popcnt") format src (OpReg dst)
    pprInstr (BSF format src dst)    = pprOpOp (sLit "bsf")    format src (OpReg dst)
    pprInstr (BSR format src dst)    = pprOpOp (sLit "bsr")    format src (OpReg dst)

    pprInstr (PREFETCH NTA format src ) = pprFormatOp_ (sLit "prefetchnta") format src
    pprInstr (PREFETCH Lvl0 format src) = pprFormatOp_ (sLit "prefetcht0") format src
    pprInstr (PREFETCH Lvl1 format src) = pprFormatOp_ (sLit "prefetcht1") format src
    pprInstr (PREFETCH Lvl2 format src) = pprFormatOp_ (sLit "prefetcht2") format src

    pprInstr (NOT format op) = pprFormatOp (sLit "not") format op
    pprInstr (BSWAP format op) = pprFormatOp (sLit "bswap") format (OpReg op)
    pprInstr (NEGI format op) = pprFormatOp (sLit "neg") format op

    pprInstr (SHL format src dst) = pprShift (sLit "shl") format src dst
    pprInstr (SAR format src dst) = pprShift (sLit "sar") format src dst
    pprInstr (SHR format src dst) = pprShift (sLit "shr") format src dst

    pprInstr (BT  format imm src) = pprFormatImmOp (sLit "bt") format imm src

    pprInstr (CMP format src dst)
      | isFloatFormat format =  pprFormatOpOp (sLit "ucomi") format src dst -- SSE2
      | otherwise     =  pprFormatOpOp (sLit "cmp")   format src dst

    pprInstr (TEST format src dst) = sdocWithPlatform $ \platform ->
      let format' = case (src,dst) of
            -- Match instructions like 'test $0x3,%esi' or 'test $0x7,%rbx'.
            -- We can replace them by equivalent, but smaller instructions
            -- by reducing the size of the immediate operand as far as possible.
            -- (We could handle masks larger than a single byte too,
            -- but it would complicate the code considerably
            -- and tag checks are by far the most common case.)
            -- The mask must have the high bit clear for this smaller encoding
            -- to be completely equivalent to the original; in particular so
            -- that the signed comparison condition bits are the same as they
            -- would be if doing a full word comparison. See Trac #13425.
            (OpImm (ImmInteger mask), OpReg dstReg)
              | 0 <= mask && mask < 128 -> minSizeOfReg platform dstReg
            _ -> format
      in pprFormatOpOp (sLit "test") format' src dst
      where
        minSizeOfReg platform (RegReal (RealRegSingle i))
          | target32Bit platform && i <= 3        = II8  -- al, bl, cl, dl
          | target32Bit platform && i <= 7        = II16 -- si, di, bp, sp
          | not (target32Bit platform) && i <= 15 = II8  -- al .. r15b
        minSizeOfReg _ _ = format                 -- other

    pprInstr (PUSH format op) = pprFormatOp (sLit "push") format op
    pprInstr (POP format op) = pprFormatOp (sLit "pop") format op

    -- both unused (SDM):
    -- pprInstr PUSHA = text "\tpushal"
    -- pprInstr POPA = text "\tpopal"

    pprInstr NOP = text "\tnop"
    pprInstr (CLTD II32) = text "\tcltd"
    pprInstr (CLTD II64) = text "\tcqto"

    pprInstr (SETCC cond op) = pprCondInstr (sLit "set") cond (pprOperand II8 op)

    pprInstr (JXX cond blockid)
      = pprCondInstr (sLit "j") cond (ppr lab)
      where lab = mkAsmTempLabel (getUnique blockid)

    pprInstr        (JXX_GBL cond imm) = pprCondInstr (sLit "j") cond (pprImm imm)

    pprInstr        (JMP (OpImm imm) _) = text "\tjmp " <> pprImm imm
    pprInstr (JMP op _)          = sdocWithPlatform $ \platform ->
                                   text "\tjmp *"
                                       <> pprOperand (archWordFormat (target32Bit platform)) op
    pprInstr (JMP_TBL op _ _ _)  = pprInstr (JMP op [])
    pprInstr        (CALL (Left imm) _)    = text "\tcall " <> pprImm imm
    pprInstr (CALL (Right reg) _)   = sdocWithPlatform $ \platform ->
                                      text "\tcall *"
                                          <> pprReg (archWordFormat (target32Bit platform)) reg

    pprInstr (IDIV fmt op)   = pprFormatOp (sLit "idiv") fmt op
    pprInstr (DIV fmt op)    = pprFormatOp (sLit "div")  fmt op
    pprInstr (IMUL2 fmt op)  = pprFormatOp (sLit "imul") fmt op

    -- x86_64 only
    pprInstr (MUL format op1 op2) = pprFormatOpOp (sLit "mul") format op1 op2
    pprInstr (MUL2 format op) = pprFormatOp (sLit "mul") format op

    pprInstr (FDIV format op1 op2) = pprFormatOpOp (sLit "div") format op1 op2

    pprInstr (CVTSS2SD from to)      = pprRegReg (sLit "cvtss2sd") from to
    pprInstr (CVTSD2SS from to)      = pprRegReg (sLit "cvtsd2ss") from to
    pprInstr (CVTTSS2SIQ fmt from to) = pprFormatFormatOpReg (sLit "cvttss2si") FF32 fmt from to
    pprInstr (CVTTSD2SIQ fmt from to) = pprFormatFormatOpReg (sLit "cvttsd2si") FF64 fmt from to
    pprInstr (CVTSI2SS fmt from to)   = pprFormatOpReg (sLit "cvtsi2ss") fmt from to
    pprInstr (CVTSI2SD fmt from to)   = pprFormatOpReg (sLit "cvtsi2sd") fmt from to

        -- FETCHGOT for PIC on ELF platforms
    pprInstr (FETCHGOT reg)
       = vcat [ text "\tcall 1f",
                hcat [ text "1:\tpopl\t", pprReg II32 reg ],
                hcat [ text "\taddl\t$_GLOBAL_OFFSET_TABLE_+(.-1b), ",
                       pprReg II32 reg ]
              ]

        -- FETCHPC for PIC on Darwin/x86
        -- get the instruction pointer into a register
        -- (Terminology note: the IP is called Program Counter on PPC,
        --  and it's a good thing to use the same name on both platforms)
    pprInstr (FETCHPC reg)
       = vcat [ text "\tcall 1f",
                hcat [ text "1:\tpopl\t", pprReg II32 reg ]
              ]

    -- -----------------------------------------------------------------------------
    -- i386 floating-point

    -- Simulating a flat register set on the x86 FP stack is tricky.
    -- you have to free %st(7) before pushing anything on the FP reg stack
    -- so as to preclude the possibility of a FP stack overflow exception.
    pprInstr g@(GMOV src dst)
       | src == dst
       = empty
       | otherwise
       = pprG g (hcat [gtab, gpush src 0, gsemi, gpop dst 1])

    -- GLD fmt addr dst ==> FLDsz addr ; FSTP (dst+1)
    pprInstr g@(GLD fmt addr dst)
     = pprG g (hcat [gtab, text "fld", pprFormat_x87 fmt, gsp,
                     pprAddr addr, gsemi, gpop dst 1])

    -- GST fmt src addr ==> FLD dst ; FSTPsz addr
    pprInstr g@(GST fmt src addr)
     | src == fake0 && fmt /= FF80 -- fstt instruction doesn't exist
     = pprG g (hcat [gtab,
                     text "fst", pprFormat_x87 fmt, gsp, pprAddr addr])
     | otherwise
     = pprG g (hcat [gtab, gpush src 0, gsemi,
                     text "fstp", pprFormat_x87 fmt, gsp, pprAddr addr])

    pprInstr g@(GLDZ dst)
     = pprG g (hcat [gtab, text "fldz ; ", gpop dst 1])
    pprInstr g@(GLD1 dst)
     = pprG g (hcat [gtab, text "fld1 ; ", gpop dst 1])

    pprInstr (GFTOI src dst)
       = pprInstr (GDTOI src dst)

    pprInstr g@(GDTOI src dst)
       = pprG g (vcat [
             hcat [gtab, text "subl $8, %esp ; fnstcw 4(%esp)"],
             hcat [gtab, gpush src 0],
             hcat [gtab, text "movzwl 4(%esp), ", reg,
                         text " ; orl $0xC00, ", reg],
             hcat [gtab, text "movl ", reg, text ", 0(%esp) ; fldcw 0(%esp)"],
             hcat [gtab, text "fistpl 0(%esp)"],
             hcat [gtab, text "fldcw 4(%esp) ; movl 0(%esp), ", reg],
             hcat [gtab, text "addl $8, %esp"]
         ])
       where
         reg = pprReg II32 dst

    pprInstr (GITOF src dst)
       = pprInstr (GITOD src dst)

    pprInstr g@(GITOD src dst)
       = pprG g (hcat [gtab, text "pushl ", pprReg II32 src,
                       text " ; fildl (%esp) ; ",
                       gpop dst 1, text " ; addl $4,%esp"])

    pprInstr g@(GDTOF src dst)
      = pprG g (vcat [gtab <> gpush src 0,
                      gtab <> text "subl $4,%esp ; fstps (%esp) ; flds (%esp) ; addl $4,%esp ;",
                      gtab <> gpop dst 1])

    {- Gruesome swamp follows.  If you're unfortunate enough to have ventured
       this far into the jungle AND you give a Rat's Ass (tm) what's going
       on, here's the deal.  Generate code to do a floating point comparison
       of src1 and src2, of kind cond, and set the Zero flag if true.

       The complications are to do with handling NaNs correctly.  We want the
       property that if either argument is NaN, then the result of the
       comparison is False ... except if we're comparing for inequality,
       in which case the answer is True.

       Here's how the general (non-inequality) case works.  As an
       example, consider generating the an equality test:

         pushl %eax         -- we need to mess with this
         <get src1 to top of FPU stack>
         fcomp <src2 location in FPU stack> and pop pushed src1
                    -- Result of comparison is in FPU Status Register bits
                    -- C3 C2 and C0
         fstsw %ax  -- Move FPU Status Reg to %ax
         sahf       -- move C3 C2 C0 from %ax to integer flag reg
         -- now the serious magic begins
         setpo %ah     -- %ah = if comparable(neither arg was NaN) then 1 else 0
         sete  %al     -- %al = if arg1 == arg2 then 1 else 0
         andb %ah,%al  -- %al &= %ah
                       -- so %al == 1 iff (comparable && same); else it holds 0
         decb %al      -- %al == 0, ZeroFlag=1  iff (comparable && same);
                          else %al == 0xFF, ZeroFlag=0
         -- the zero flag is now set as we desire.
         popl %eax

       The special case of inequality differs thusly:

         setpe %ah     -- %ah = if incomparable(either arg was NaN) then 1 else 0
         setne %al     -- %al = if arg1 /= arg2 then 1 else 0
         orb %ah,%al   -- %al = if (incomparable || different) then 1 else 0
         decb %al      -- if (incomparable || different) then (%al == 0, ZF=1)
                                                         else (%al == 0xFF, ZF=0)
    -}
    pprInstr g@(GCMP cond src1 src2)
       | case cond of { NE -> True; _ -> False }
       = pprG g (vcat [
            hcat [gtab, text "pushl %eax ; ",gpush src1 0],
            hcat [gtab, text "fcomp ", greg src2 1,
                        text "; fstsw %ax ; sahf ;  setpe %ah"],
            hcat [gtab, text "setne %al ;  ",
                  text "orb %ah,%al ;  decb %al ;  popl %eax"]
        ])
       | otherwise
       = pprG g (vcat [
            hcat [gtab, text "pushl %eax ; ",gpush src1 0],
            hcat [gtab, text "fcomp ", greg src2 1,
                        text "; fstsw %ax ; sahf ;  setpo %ah"],
            hcat [gtab, text "set", pprCond (fix_FP_cond cond), text " %al ;  ",
                  text "andb %ah,%al ;  decb %al ;  popl %eax"]
        ])
        where
            {- On the 486, the flags set by FP compare are the unsigned ones!
               (This looks like a HACK to me.  WDP 96/03)
            -}
            fix_FP_cond :: Cond -> Cond
            fix_FP_cond GE   = GEU
            fix_FP_cond GTT  = GU
            fix_FP_cond LTT  = LU
            fix_FP_cond LE   = LEU
            fix_FP_cond EQQ  = EQQ
            fix_FP_cond NE   = NE
            fix_FP_cond _    = panic "X86.Ppr.fix_FP_cond: no match"
            -- there should be no others

    pprInstr g@(GABS _ src dst)
       = pprG g (hcat [gtab, gpush src 0, text " ; fabs ; ", gpop dst 1])

    pprInstr g@(GNEG _ src dst)
       = pprG g (hcat [gtab, gpush src 0, text " ; fchs ; ", gpop dst 1])

    pprInstr g@(GSQRT fmt src dst)
       = pprG g (hcat [gtab, gpush src 0, text " ; fsqrt"] $$
                 hcat [gtab, gcoerceto fmt, gpop dst 1])

    pprInstr g@(GSIN fmt l1 l2 src dst)
       = pprG g (pprTrigOp "fsin" False l1 l2 src dst fmt)

    pprInstr g@(GCOS fmt l1 l2 src dst)
       = pprG g (pprTrigOp "fcos" False l1 l2 src dst fmt)

    pprInstr g@(GTAN fmt l1 l2 src dst)
       = pprG g (pprTrigOp "fptan" True l1 l2 src dst fmt)

    -- In the translations for GADD, GMUL, GSUB and GDIV,
    -- the first two cases are mere optimisations.  The otherwise clause
    -- generates correct code under all circumstances.

    pprInstr g@(GADD _ src1 src2 dst)
       | src1 == dst
       = pprG g (text "\t#GADD-xxxcase1" $$
                 hcat [gtab, gpush src2 0,
                       text " ; faddp %st(0),", greg src1 1])
       | src2 == dst
       = pprG g (text "\t#GADD-xxxcase2" $$
                 hcat [gtab, gpush src1 0,
                       text " ; faddp %st(0),", greg src2 1])
       | otherwise
       = pprG g (hcat [gtab, gpush src1 0,
                       text " ; fadd ", greg src2 1, text ",%st(0)",
                       gsemi, gpop dst 1])

    pprInstr g@(GMUL _ src1 src2 dst)
       | src1 == dst
       = pprG g (text "\t#GMUL-xxxcase1" $$
                 hcat [gtab, gpush src2 0,
                       text " ; fmulp %st(0),", greg src1 1])
       | src2 == dst
       = pprG g (text "\t#GMUL-xxxcase2" $$
                 hcat [gtab, gpush src1 0,
                       text " ; fmulp %st(0),", greg src2 1])
       | otherwise
       = pprG g (hcat [gtab, gpush src1 0,
                 text " ; fmul ", greg src2 1, text ",%st(0)",
                 gsemi, gpop dst 1])

    pprInstr g@(GSUB _ src1 src2 dst)
       | src1 == dst
       = pprG g (text "\t#GSUB-xxxcase1" $$
                 hcat [gtab, gpush src2 0,
                       text " ; fsubrp %st(0),", greg src1 1])
       | src2 == dst
       = pprG g (text "\t#GSUB-xxxcase2" $$
                 hcat [gtab, gpush src1 0,
                       text " ; fsubp %st(0),", greg src2 1])
       | otherwise
       = pprG g (hcat [gtab, gpush src1 0,
                       text " ; fsub ", greg src2 1, text ",%st(0)",
                       gsemi, gpop dst 1])

    pprInstr g@(GDIV _ src1 src2 dst)
       | src1 == dst
       = pprG g (text "\t#GDIV-xxxcase1" $$
                 hcat [gtab, gpush src2 0,
                       text " ; fdivrp %st(0),", greg src1 1])
       | src2 == dst
       = pprG g (text "\t#GDIV-xxxcase2" $$
                 hcat [gtab, gpush src1 0,
                       text " ; fdivp %st(0),", greg src2 1])
       | otherwise
       = pprG g (hcat [gtab, gpush src1 0,
                       text " ; fdiv ", greg src2 1, text ",%st(0)",
                       gsemi, gpop dst 1])

    pprInstr GFREE
       = vcat [ text "\tffree %st(0) ;ffree %st(1) ;ffree %st(2) ;ffree %st(3)",
                text "\tffree %st(4) ;ffree %st(5)"
              ]

    -- Atomics

    pprInstr (LOCK i) = text "\tlock" $$ pprInstr i

    pprInstr MFENCE = text "\tmfence"

    pprInstr (XADD format src dst) = pprFormatOpOp (sLit "xadd") format src dst

    pprInstr (CMPXCHG format src dst)
       = pprFormatOpOp (sLit "cmpxchg") format src dst

    pprInstr _
            = panic "X86.Ppr.pprInstr: no match"

    pprTrigOp :: String -> Bool -> CLabel -> CLabel
              -> Reg -> Reg -> Format -> SDoc
    pprTrigOp op -- fsin, fcos or fptan
              isTan -- we need a couple of extra steps if we're doing tan
              l1 l2 -- internal labels for us to use
              src dst fmt
        = -- We'll be needing %eax later on
          hcat [gtab, text "pushl %eax;"] $$
          -- tan is going to use an extra space on the FP stack
          (if isTan then hcat [gtab, text "ffree %st(6)"] else empty) $$
          -- First put the value in %st(0) and try to apply the op to it
          hcat [gpush src 0, text ("; " ++ op)] $$
          -- Now look to see if C2 was set (overflow, |value| >= 2^63)
          hcat [gtab, text "fnstsw %ax"] $$
          hcat [gtab, text "test   $0x400,%eax"] $$
          -- If we were in bounds then jump to the end
          hcat [gtab, text "je     " <> ppr l1] $$
          -- Otherwise we need to shrink the value. Start by
          -- loading pi, doubleing it (by adding it to itself),
          -- and then swapping pi with the value, so the value we
          -- want to apply op to is in %st(0) again
          hcat [gtab, text "ffree %st(7); fldpi"] $$
          hcat [gtab, text "fadd   %st(0),%st"] $$
          hcat [gtab, text "fxch   %st(1)"] $$
          -- Now we have a loop in which we make the value smaller,
          -- see if it's small enough, and loop if not
          (ppr l2 <> char ':') $$
          hcat [gtab, text "fprem1"] $$
          -- My Debian libc uses fstsw here for the tan code, but I can't
          -- see any reason why it should need to be different for tan.
          hcat [gtab, text "fnstsw %ax"] $$
          hcat [gtab, text "test   $0x400,%eax"] $$
          hcat [gtab, text "jne    " <> ppr l2] $$
          hcat [gtab, text "fstp   %st(1)"] $$
          hcat [gtab, text op] $$
          (ppr l1 <> char ':') $$
          -- Pop the 1.0 tan gave us
          (if isTan then hcat [gtab, text "fstp %st(0)"] else empty) $$
          -- Restore %eax
          hcat [gtab, text "popl %eax;"] $$
          -- And finally make the result the right size
          hcat [gtab, gcoerceto fmt, gpop dst 1]

    --------------------------

    -- coerce %st(0) to the specified size
    gcoerceto :: Format -> SDoc
    gcoerceto FF64 = empty
    gcoerceto FF32 = empty --text "subl $4,%esp ; fstps (%esp) ; flds (%esp) ; addl $4,%esp ; "
    gcoerceto _    = panic "X86.Ppr.gcoerceto: no match"

    gpush :: Reg -> RegNo -> SDoc
    gpush reg offset
       = hcat [text "fld ", greg reg offset]

    gpop :: Reg -> RegNo -> SDoc
    gpop reg offset
       = hcat [text "fstp ", greg reg offset]

    greg :: Reg -> RegNo -> SDoc
    greg reg offset = text "%st(" <> int (gregno reg - firstfake+offset) <> char ')'

    gsemi :: SDoc
    gsemi = text " ; "

    gtab :: SDoc
    gtab  = char '\t'

    gsp :: SDoc
    gsp   = char ' '

    gregno :: Reg -> RegNo
    gregno (RegReal (RealRegSingle i)) = i
    gregno _           = --pprPanic "gregno" (ppr other)
                         999   -- bogus; only needed for debug printing

    pprG :: Instr -> SDoc -> SDoc
    pprG fake actual
       = (char '#' <> pprGInstr fake) $$ actual

    pprGInstr :: Instr -> SDoc
    pprGInstr (GMOV src dst)   = pprFormatRegReg (sLit "gmov") FF64 src dst
    pprGInstr (GLD fmt src dst) = pprFormatAddrReg (sLit "gld") fmt src dst
    pprGInstr (GST fmt src dst) = pprFormatRegAddr (sLit "gst") fmt src dst

    pprGInstr (GLDZ dst) = pprFormatReg (sLit "gldz") FF64 dst
    pprGInstr (GLD1 dst) = pprFormatReg (sLit "gld1") FF64 dst

    pprGInstr (GFTOI src dst) = pprFormatFormatRegReg (sLit "gftoi") FF32 II32 src dst
    pprGInstr (GDTOI src dst) = pprFormatFormatRegReg (sLit "gdtoi") FF64 II32 src dst

    pprGInstr (GITOF src dst) = pprFormatFormatRegReg (sLit "gitof") II32 FF32 src dst
    pprGInstr (GITOD src dst) = pprFormatFormatRegReg (sLit "gitod") II32 FF64 src dst
    pprGInstr (GDTOF src dst) = pprFormatFormatRegReg (sLit "gdtof") FF64 FF32 src dst

    pprGInstr (GCMP co src dst) = pprCondRegReg (sLit "gcmp_") FF64 co src dst
    pprGInstr (GABS fmt src dst) = pprFormatRegReg (sLit "gabs") fmt src dst
    pprGInstr (GNEG fmt src dst) = pprFormatRegReg (sLit "gneg") fmt src dst
    pprGInstr (GSQRT fmt src dst) = pprFormatRegReg (sLit "gsqrt") fmt src dst
    pprGInstr (GSIN fmt _ _ src dst) = pprFormatRegReg (sLit "gsin") fmt src dst
    pprGInstr (GCOS fmt _ _ src dst) = pprFormatRegReg (sLit "gcos") fmt src dst
    pprGInstr (GTAN fmt _ _ src dst) = pprFormatRegReg (sLit "gtan") fmt src dst

    pprGInstr (GADD fmt src1 src2 dst) = pprFormatRegRegReg (sLit "gadd") fmt src1 src2 dst
    pprGInstr (GSUB fmt src1 src2 dst) = pprFormatRegRegReg (sLit "gsub") fmt src1 src2 dst
    pprGInstr (GMUL fmt src1 src2 dst) = pprFormatRegRegReg (sLit "gmul") fmt src1 src2 dst
    pprGInstr (GDIV fmt src1 src2 dst) = pprFormatRegRegReg (sLit "gdiv") fmt src1 src2 dst

    pprGInstr _ = panic "X86.Ppr.pprGInstr: no match"

    pprDollImm :: Imm -> SDoc
    pprDollImm i = text "$" <> pprImm i

    pprOperand :: Format -> Operand -> SDoc
    pprOperand f (OpReg r)   = pprReg f r
    pprOperand _ (OpImm i)   = pprDollImm i
    pprOperand _ (OpAddr ea) = pprAddr ea

    pprMnemonic_  :: LitString -> SDoc
    pprMnemonic_ name =
       char '\t' <> ptext name <> space

    pprMnemonic  :: LitString -> Format -> SDoc
    pprMnemonic name format =
       char '\t' <> ptext name <> pprFormat format <> space

    pprFormatImmOp :: LitString -> Format -> Imm -> Operand -> SDoc
    pprFormatImmOp name format imm op1
      = hcat [
            pprMnemonic name format,
            char '$',
            pprImm imm,
            comma,
            pprOperand format op1
        ]

    pprFormatOp_ :: LitString -> Format -> Operand -> SDoc
    pprFormatOp_ name format op1
      = hcat [
            pprMnemonic_ name ,
            pprOperand format op1
        ]

    pprFormatOp :: LitString -> Format -> Operand -> SDoc
    pprFormatOp name format op1
      = hcat [
            pprMnemonic name format,
            pprOperand format op1
        ]

    pprFormatOpOp :: LitString -> Format -> Operand -> Operand -> SDoc
    pprFormatOpOp name format op1 op2
      = hcat [
            pprMnemonic name format,
            pprOperand format op1,
            comma,
            pprOperand format op2
        ]

    pprOpOp :: LitString -> Format -> Operand -> Operand -> SDoc
    pprOpOp name format op1 op2
      = hcat [
            pprMnemonic_ name,
            pprOperand format op1,
            comma,
            pprOperand format op2
        ]

    pprFormatReg :: LitString -> Format -> Reg -> SDoc
    pprFormatReg name format reg1
      = hcat [
            pprMnemonic name format,
            pprReg format reg1
        ]

    pprFormatRegReg :: LitString -> Format -> Reg -> Reg -> SDoc
    pprFormatRegReg name format reg1 reg2
      = hcat [
            pprMnemonic name format,
            pprReg format reg1,
            comma,
            pprReg format reg2
        ]

    pprRegReg :: LitString -> Reg -> Reg -> SDoc
    pprRegReg name reg1 reg2
      = sdocWithPlatform $ \platform ->
        hcat [
            pprMnemonic_ name,
            pprReg (archWordFormat (target32Bit platform)) reg1,
            comma,
            pprReg (archWordFormat (target32Bit platform)) reg2
        ]

    pprFormatOpReg :: LitString -> Format -> Operand -> Reg -> SDoc
    pprFormatOpReg name format op1 reg2
      = sdocWithPlatform $ \platform ->
        hcat [
            pprMnemonic name format,
            pprOperand format op1,
            comma,
            pprReg (archWordFormat (target32Bit platform)) reg2
        ]

    pprCondOpReg :: LitString -> Format -> Cond -> Operand -> Reg -> SDoc
    pprCondOpReg name format cond op1 reg2
      = hcat [
            char '\t',
            ptext name,
            pprCond cond,
            space,
            pprOperand format op1,
            comma,
            pprReg format reg2
        ]

    pprCondRegReg :: LitString -> Format -> Cond -> Reg -> Reg -> SDoc
    pprCondRegReg name format cond reg1 reg2
      = hcat [
            char '\t',
            ptext name,
            pprCond cond,
            space,
            pprReg format reg1,
            comma,
            pprReg format reg2
        ]

    pprFormatFormatRegReg :: LitString -> Format -> Format -> Reg -> Reg -> SDoc
    pprFormatFormatRegReg name format1 format2 reg1 reg2
      = hcat [
            char '\t',
            ptext name,
            pprFormat format1,
            pprFormat format2,
            space,
            pprReg format1 reg1,
            comma,
            pprReg format2 reg2
        ]

    pprFormatFormatOpReg :: LitString -> Format -> Format -> Operand -> Reg -> SDoc
    pprFormatFormatOpReg name format1 format2 op1 reg2
      = hcat [
            pprMnemonic name format2,
            pprOperand format1 op1,
            comma,
            pprReg format2 reg2
        ]

    pprFormatRegRegReg :: LitString -> Format -> Reg -> Reg -> Reg -> SDoc
    pprFormatRegRegReg name format reg1 reg2 reg3
      = hcat [
            pprMnemonic name format,
            pprReg format reg1,
            comma,
            pprReg format reg2,
            comma,
            pprReg format reg3
        ]

    pprFormatAddrReg :: LitString -> Format -> AddrMode -> Reg -> SDoc
    pprFormatAddrReg name format op dst
      = hcat [
            pprMnemonic name format,
            pprAddr op,
            comma,
            pprReg format dst
        ]

    pprFormatRegAddr :: LitString -> Format -> Reg -> AddrMode -> SDoc
    pprFormatRegAddr name format src op
      = hcat [
            pprMnemonic name format,
            pprReg format src,
            comma,
            pprAddr op
        ]

    pprShift :: LitString -> Format -> Operand -> Operand -> SDoc
    pprShift name format src dest
      = hcat [
            pprMnemonic name format,
            pprOperand II8 src,  -- src is 8-bit sized
            comma,
            pprOperand format dest
        ]

    pprFormatOpOpCoerce :: LitString -> Format -> Format -> Operand -> Operand -> SDoc
    pprFormatOpOpCoerce name format1 format2 op1 op2
      = hcat [ char '\t', ptext name, pprFormat format1, pprFormat format2, space,
            pprOperand format1 op1,
            comma,
            pprOperand format2 op2
        ]

    pprCondInstr :: LitString -> Cond -> SDoc -> SDoc
    pprCondInstr name cond arg
      = hcat [ char '\t', ptext name, pprCond cond, space, arg]