2 -- | A description of the register set of the X86.
3 -- This isn't used directly in GHC proper.
5 -- See RegArchBase.hs for the reference.
6 -- See MachRegs.hs for the actual trivColorable function used in GHC.
17 import RegArchBase (Reg(..), RegSub(..), RegClass(..))
21 -- | Determine the class of a register
22 classOfReg :: Reg -> RegClass
27 RegSub SubL16 r -> ClassG16
28 RegSub SubL8 r -> ClassG8
29 RegSub SubL8H r -> ClassG8
32 -- | Determine all the regs that make up a certain class.
34 regsOfClass :: RegClass -> UniqSet Reg
38 -> mkUniqSet [ Reg ClassG32 i | i <- [0..7] ]
41 -> mkUniqSet [ RegSub SubL16 (Reg ClassG32 i) | i <- [0..7] ]
45 (mkUniqSet [ RegSub SubL8 (Reg ClassG32 i) | i <- [0..3] ])
46 (mkUniqSet [ RegSub SubL8H (Reg ClassG32 i) | i <- [0..3] ])
49 -> mkUniqSet [ Reg ClassF64 i | i <- [0..5] ]
52 -- | Determine the common name of a reg
53 -- returns Nothing if this reg is not part of the machine.
55 regName :: Reg -> Maybe String
59 | i <= 7 -> Just ([ "eax", "ebx", "ecx", "edx", "ebp", "esi", "edi", "esp" ] !! i)
61 RegSub SubL16 (Reg ClassG32 i)
62 | i <= 7 -> Just ([ "ax", "bx", "cx", "dx", "bp", "si", "di", "sp"] !! i)
64 RegSub SubL8 (Reg ClassG32 i)
65 | i <= 3 -> Just ([ "al", "bl", "cl", "dl"] !! i)
67 RegSub SubL8H (Reg ClassG32 i)
68 | i <= 3 -> Just ([ "ah", "bh", "ch", "dh"] !! i)
73 -- | Which regs alias what other regs
74 regAlias :: Reg -> UniqSet Reg
78 -- 32 bit regs alias all of the subregs
81 -- for eax, ebx, ecx, eds
83 -> mkUniqSet $ [ Reg ClassG32 i, RegSub SubL16 reg, RegSub SubL8 reg, RegSub SubL8H reg ]
85 -- for esi, edi, esp, ebp
87 -> mkUniqSet $ [ Reg ClassG32 i, RegSub SubL16 reg ]
90 -- 16 bit subregs alias the whole reg
91 RegSub SubL16 r@(Reg ClassG32 i)
94 -- 8 bit subregs alias the 32 and 16, but not the other 8 bit subreg
95 RegSub SubL8 r@(Reg ClassG32 i)
96 -> mkUniqSet $ [ r, RegSub SubL16 r, RegSub SubL8 r ]
98 RegSub SubL8H r@(Reg ClassG32 i)
99 -> mkUniqSet $ [ r, RegSub SubL16 r, RegSub SubL8H r ]
105 _ -> error "regAlias: invalid register"
108 -- | Optimised versions of RegColorBase.{worst, squeese} specific to x86
110 worst :: Int -> RegClass -> RegClass -> Int
111 worst n classN classC
129 ClassG32 -> min (n*2) 8
130 ClassG16 -> min (n*2) 8
139 squeese :: RegClass -> [(Int, RegClass)] -> Int
140 squeese classN countCs
141 = sum (map (\(i, classC) -> worst i classN classC) countCs)