+
+#elif defined(sparc_TARGET_ARCH)
+--------------------------------------------------------------------------------
+-- SPARC is like PPC, except for twinning of floating point regs.
+-- When we allocate a double reg we must take an even numbered
+-- float reg, as well as the one after it.
+
+
+-- Holds bitmaps showing what registers are currently allocated.
+-- The float and double reg bitmaps overlap, but we only alloc
+-- float regs into the float map, and double regs into the double map.
+--
+-- Free regs have a bit set in the corresponding bitmap.
+--
+data FreeRegs
+ = FreeRegs
+ !Word32 -- int reg bitmap regs 0..31
+ !Word32 -- float reg bitmap regs 32..63
+ !Word32 -- double reg bitmap regs 32..63
+ deriving( Show )
+
+
+-- | A reg map where no regs are free to be allocated.
+noFreeRegs :: FreeRegs
+noFreeRegs = FreeRegs 0 0 0
+
+
+-- | The initial set of free regs.
+-- Don't treat the top half of reg pairs we're using as doubles as being free.
+initFreeRegs :: FreeRegs
+initFreeRegs
+ = regs
+ where
+-- freeDouble = getFreeRegs RcDouble regs
+ regs = foldr releaseReg noFreeRegs allocable
+ allocable = allocatableRegs \\ doublePairs
+ doublePairs = [43, 45, 47, 49, 51, 53]
+
+
+-- | Get all the free registers of this class.
+getFreeRegs :: RegClass -> FreeRegs -> [RegNo] -- lazilly
+getFreeRegs cls (FreeRegs g f d)
+ | RcInteger <- cls = go g 1 0
+ | RcFloat <- cls = go f 1 32
+ | RcDouble <- cls = go d 1 32
+ | otherwise = pprPanic "RegAllocLinear.getFreeRegs: Bad register class " (ppr cls)
+ where
+ go _ 0 _ = []
+ go x m i | x .&. m /= 0 = i : (go x (m `shiftL` 1) $! i+1)
+ | otherwise = go x (m `shiftL` 1) $! i+1
+{-
+showFreeRegs :: FreeRegs -> String
+showFreeRegs regs
+ = "FreeRegs\n"
+ ++ " integer: " ++ (show $ getFreeRegs RcInteger regs) ++ "\n"
+ ++ " float: " ++ (show $ getFreeRegs RcFloat regs) ++ "\n"
+ ++ " double: " ++ (show $ getFreeRegs RcDouble regs) ++ "\n"
+-}
+
+{-
+-- | Check whether a reg is free
+regIsFree :: RegNo -> FreeRegs -> Bool
+regIsFree r (FreeRegs g f d)
+
+ -- a general purpose reg
+ | r <= 31
+ , mask <- 1 `shiftL` fromIntegral r
+ = g .&. mask /= 0
+
+ -- use the first 22 float regs as double precision
+ | r >= 32
+ , r <= 53
+ , mask <- 1 `shiftL` (fromIntegral r - 32)
+ = d .&. mask /= 0
+
+ -- use the last 10 float regs as single precision
+ | otherwise
+ , mask <- 1 `shiftL` (fromIntegral r - 32)
+ = f .&. mask /= 0
+-}
+
+-- | Grab a register.
+grabReg :: RegNo -> FreeRegs -> FreeRegs
+grabReg r (FreeRegs g f d)
+
+ -- a general purpose reg
+ | r <= 31
+ , mask <- complement (1 `shiftL` fromIntegral r)
+ = FreeRegs (g .&. mask) f d
+
+ -- use the first 22 float regs as double precision
+ | r >= 32
+ , r <= 53
+ , mask <- complement (1 `shiftL` (fromIntegral r - 32))
+ = FreeRegs g f (d .&. mask)
+
+ -- use the last 10 float regs as single precision
+ | otherwise
+ , mask <- complement (1 `shiftL` (fromIntegral r - 32))
+ = FreeRegs g (f .&. mask) d
+
+
+
+-- | Release a register from allocation.
+-- The register liveness information says that most regs die after a C call,
+-- but we still don't want to allocate to some of them.
+--
+releaseReg :: RegNo -> FreeRegs -> FreeRegs
+releaseReg r regs@(FreeRegs g f d)
+
+ -- used by STG machine, or otherwise unavailable
+ | r >= 0 && r <= 15 = regs
+ | r >= 17 && r <= 21 = regs
+ | r >= 24 && r <= 31 = regs
+ | r >= 32 && r <= 41 = regs
+ | r >= 54 && r <= 59 = regs
+
+ -- never release the high part of double regs.
+ | r == 43 = regs
+ | r == 45 = regs
+ | r == 47 = regs
+ | r == 49 = regs
+ | r == 51 = regs
+ | r == 53 = regs
+
+ -- a general purpose reg
+ | r <= 31
+ , mask <- 1 `shiftL` fromIntegral r
+ = FreeRegs (g .|. mask) f d
+
+ -- use the first 22 float regs as double precision
+ | r >= 32
+ , r <= 53
+ , mask <- 1 `shiftL` (fromIntegral r - 32)
+ = FreeRegs g f (d .|. mask)
+
+ -- use the last 10 float regs as single precision
+ | otherwise
+ , mask <- 1 `shiftL` (fromIntegral r - 32)
+ = FreeRegs g (f .|. mask) d
+
+
+-- | Allocate a register in the map.
+allocateReg :: RegNo -> FreeRegs -> FreeRegs
+allocateReg r regs -- (FreeRegs g f d)
+
+ -- if the reg isn't actually free then we're in trouble
+{- | not $ regIsFree r regs
+ = pprPanic
+ "RegAllocLinear.allocateReg"
+ (text "reg " <> ppr r <> text " is not free")
+-}
+ | otherwise
+ = grabReg r regs
+
+
+
+--------------------------------------------------------------------------------