never executed always true always false

    1 module GHC.CmmToAsm.Reg.Linear.FreeRegs (
    2     FR(..),
    3     maxSpillSlots
    4 )
    5 where
    6 
    7 import GHC.Prelude
    8 
    9 import GHC.Platform.Reg
   10 import GHC.Platform.Reg.Class
   11 
   12 import GHC.CmmToAsm.Config
   13 import GHC.Utils.Panic
   14 import GHC.Platform
   15 
   16 -- -----------------------------------------------------------------------------
   17 -- The free register set
   18 -- This needs to be *efficient*
   19 -- Here's an inefficient 'executable specification' of the FreeRegs data type:
   20 --
   21 --      type FreeRegs = [RegNo]
   22 --      noFreeRegs = 0
   23 --      releaseReg n f = if n `elem` f then f else (n : f)
   24 --      initFreeRegs = allocatableRegs
   25 --      getFreeRegs cls f = filter ( (==cls) . regClass . RealReg ) f
   26 --      allocateReg f r = filter (/= r) f
   27 
   28 import qualified GHC.CmmToAsm.Reg.Linear.PPC     as PPC
   29 import qualified GHC.CmmToAsm.Reg.Linear.SPARC   as SPARC
   30 import qualified GHC.CmmToAsm.Reg.Linear.X86     as X86
   31 import qualified GHC.CmmToAsm.Reg.Linear.X86_64  as X86_64
   32 import qualified GHC.CmmToAsm.Reg.Linear.AArch64 as AArch64
   33 
   34 import qualified GHC.CmmToAsm.PPC.Instr     as PPC.Instr
   35 import qualified GHC.CmmToAsm.SPARC.Instr   as SPARC.Instr
   36 import qualified GHC.CmmToAsm.X86.Instr     as X86.Instr
   37 import qualified GHC.CmmToAsm.AArch64.Instr as AArch64.Instr
   38 
   39 class Show freeRegs => FR freeRegs where
   40     frAllocateReg :: Platform -> RealReg -> freeRegs -> freeRegs
   41     frGetFreeRegs :: Platform -> RegClass -> freeRegs -> [RealReg]
   42     frInitFreeRegs :: Platform -> freeRegs
   43     frReleaseReg :: Platform -> RealReg -> freeRegs -> freeRegs
   44 
   45 instance FR X86.FreeRegs where
   46     frAllocateReg  = \_ -> X86.allocateReg
   47     frGetFreeRegs  = X86.getFreeRegs
   48     frInitFreeRegs = X86.initFreeRegs
   49     frReleaseReg   = \_ -> X86.releaseReg
   50 
   51 instance FR X86_64.FreeRegs where
   52     frAllocateReg  = \_ -> X86_64.allocateReg
   53     frGetFreeRegs  = X86_64.getFreeRegs
   54     frInitFreeRegs = X86_64.initFreeRegs
   55     frReleaseReg   = \_ -> X86_64.releaseReg
   56 
   57 instance FR PPC.FreeRegs where
   58     frAllocateReg  = \_ -> PPC.allocateReg
   59     frGetFreeRegs  = \_ -> PPC.getFreeRegs
   60     frInitFreeRegs = PPC.initFreeRegs
   61     frReleaseReg   = \_ -> PPC.releaseReg
   62 
   63 instance FR AArch64.FreeRegs where
   64     frAllocateReg = \_ -> AArch64.allocateReg
   65     frGetFreeRegs = \_ -> AArch64.getFreeRegs
   66     frInitFreeRegs = AArch64.initFreeRegs
   67     frReleaseReg = \_ -> AArch64.releaseReg
   68 
   69 instance FR SPARC.FreeRegs where
   70     frAllocateReg  = SPARC.allocateReg
   71     frGetFreeRegs  = \_ -> SPARC.getFreeRegs
   72     frInitFreeRegs = SPARC.initFreeRegs
   73     frReleaseReg   = SPARC.releaseReg
   74 
   75 maxSpillSlots :: NCGConfig -> Int
   76 maxSpillSlots config = case platformArch (ncgPlatform config) of
   77    ArchX86       -> X86.Instr.maxSpillSlots config
   78    ArchX86_64    -> X86.Instr.maxSpillSlots config
   79    ArchPPC       -> PPC.Instr.maxSpillSlots config
   80    ArchS390X     -> panic "maxSpillSlots ArchS390X"
   81    ArchSPARC     -> SPARC.Instr.maxSpillSlots config
   82    ArchSPARC64   -> panic "maxSpillSlots ArchSPARC64"
   83    ArchARM _ _ _ -> panic "maxSpillSlots ArchARM"
   84    ArchAArch64   -> AArch64.Instr.maxSpillSlots config
   85    ArchPPC_64 _  -> PPC.Instr.maxSpillSlots config
   86    ArchAlpha     -> panic "maxSpillSlots ArchAlpha"
   87    ArchMipseb    -> panic "maxSpillSlots ArchMipseb"
   88    ArchMipsel    -> panic "maxSpillSlots ArchMipsel"
   89    ArchRISCV64   -> panic "maxSpillSlots ArchRISCV64"
   90    ArchJavaScript-> panic "maxSpillSlots ArchJavaScript"
   91    ArchUnknown   -> panic "maxSpillSlots ArchUnknown"