never executed always true always false

    1 module GHC.CmmToAsm.SPARC.Imm (
    2         -- immediate values
    3         Imm(..),
    4         strImmLit,
    5         litToImm
    6 )
    7 
    8 where
    9 
   10 import GHC.Prelude
   11 
   12 import GHC.Cmm
   13 import GHC.Cmm.CLabel
   14 
   15 import GHC.Utils.Outputable
   16 import GHC.Utils.Panic
   17 
   18 -- | An immediate value.
   19 --      Not all of these are directly representable by the machine.
   20 --      Things like ImmLit are slurped out and put in a data segment instead.
   21 --
   22 data Imm
   23         = ImmInt        Int
   24 
   25         -- Sigh.
   26         | ImmInteger    Integer
   27 
   28         -- AbstractC Label (with baggage)
   29         | ImmCLbl       CLabel
   30 
   31         -- Simple string
   32         | ImmLit        SDoc
   33         | ImmIndex      CLabel Int
   34         | ImmFloat      Rational
   35         | ImmDouble     Rational
   36 
   37         | ImmConstantSum  Imm Imm
   38         | ImmConstantDiff Imm Imm
   39 
   40         | LO    Imm
   41         | HI    Imm
   42 
   43 
   44 -- | Create a ImmLit containing this string.
   45 strImmLit :: String -> Imm
   46 strImmLit s = ImmLit (text s)
   47 
   48 
   49 -- | Convert a CmmLit to an Imm.
   50 --      Narrow to the width: a CmmInt might be out of
   51 --      range, but we assume that ImmInteger only contains
   52 --      in-range values.  A signed value should be fine here.
   53 --
   54 litToImm :: CmmLit -> Imm
   55 litToImm lit
   56  = case lit of
   57         CmmInt i w              -> ImmInteger (narrowS w i)
   58         CmmFloat f W32          -> ImmFloat f
   59         CmmFloat f W64          -> ImmDouble f
   60         CmmLabel l              -> ImmCLbl l
   61         CmmLabelOff l off       -> ImmIndex l off
   62 
   63         CmmLabelDiffOff l1 l2 off _
   64          -> ImmConstantSum
   65                 (ImmConstantDiff (ImmCLbl l1) (ImmCLbl l2))
   66                 (ImmInt off)
   67 
   68         _               -> panic "SPARC.Regs.litToImm: no match"