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Diffstat (limited to 'compiler/nativeGen/Instruction.hs')
| -rw-r--r-- | compiler/nativeGen/Instruction.hs | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/compiler/nativeGen/Instruction.hs b/compiler/nativeGen/Instruction.hs new file mode 100644 index 0000000000..22c37a5b12 --- /dev/null +++ b/compiler/nativeGen/Instruction.hs @@ -0,0 +1,159 @@ + +module Instruction ( + RegUsage(..), + noUsage, + NatCmm, + NatCmmTop, + NatBasicBlock, + Instruction(..) +) + +where + +import Reg + +import BlockId +import Cmm + +-- | Holds a list of source and destination registers used by a +-- particular instruction. +-- +-- Machine registers that are pre-allocated to stgRegs are filtered +-- out, because they are uninteresting from a register allocation +-- standpoint. (We wouldn't want them to end up on the free list!) +-- +-- As far as we are concerned, the fixed registers simply don't exist +-- (for allocation purposes, anyway). +-- +data RegUsage + = RU [Reg] [Reg] + +-- | No regs read or written to. +noUsage :: RegUsage +noUsage = RU [] [] + + +-- Our flavours of the Cmm types +-- Type synonyms for Cmm populated with native code +type NatCmm instr + = GenCmm + CmmStatic + [CmmStatic] + (ListGraph instr) + +type NatCmmTop instr + = GenCmmTop + CmmStatic + [CmmStatic] + (ListGraph instr) + + +type NatBasicBlock instr + = GenBasicBlock instr + + + + +-- | Common things that we can do with instructions, on all architectures. +-- These are used by the shared parts of the native code generator, +-- specifically the register allocators. +-- +class Instruction instr where + + -- | Get the registers that are being used by this instruction. + -- regUsage doesn't need to do any trickery for jumps and such. + -- Just state precisely the regs read and written by that insn. + -- The consequences of control flow transfers, as far as register + -- allocation goes, are taken care of by the register allocator. + -- + regUsageOfInstr + :: instr + -> RegUsage + + + -- | Apply a given mapping to all the register references in this + -- instruction. + patchRegsOfInstr + :: instr + -> (Reg -> Reg) + -> instr + + + -- | Checks whether this instruction is a jump/branch instruction. + -- One that can change the flow of control in a way that the + -- register allocator needs to worry about. + isJumpishInstr + :: instr -> Bool + + + -- | Give the possible destinations of this jump instruction. + -- Must be defined for all jumpish instructions. + jumpDestsOfInstr + :: instr -> [BlockId] + + + -- | Change the destination of this jump instruction. + -- Used in the linear allocator when adding fixup blocks for join + -- points. + patchJumpInstr + :: instr + -> (BlockId -> BlockId) + -> instr + + + -- | An instruction to spill a register into a spill slot. + mkSpillInstr + :: Reg -- ^ the reg to spill + -> Int -- ^ the current stack delta + -> Int -- ^ spill slot to use + -> instr + + + -- | An instruction to reload a register from a spill slot. + mkLoadInstr + :: Reg -- ^ the reg to reload. + -> Int -- ^ the current stack delta + -> Int -- ^ the spill slot to use + -> instr + + -- | See if this instruction is telling us the current C stack delta + takeDeltaInstr + :: instr + -> Maybe Int + + -- | Check whether this instruction is some meta thing inserted into + -- the instruction stream for other purposes. + -- + -- Not something that has to be treated as a real machine instruction + -- and have its registers allocated. + -- + -- eg, comments, delta, ldata, etc. + isMetaInstr + :: instr + -> Bool + + + + -- | Copy the value in a register to another one. + -- Must work for all register classes. + mkRegRegMoveInstr + :: Reg -- ^ source register + -> Reg -- ^ destination register + -> instr + + -- | Take the source and destination from this reg -> reg move instruction + -- or Nothing if it's not one + takeRegRegMoveInstr + :: instr + -> Maybe (Reg, Reg) + + -- | Make an unconditional jump instruction. + -- For architectures with branch delay slots, its ok to put + -- a NOP after the jump. Don't fill the delay slot with an + -- instruction that references regs or you'll confuse the + -- linear allocator. + mkJumpInstr + :: BlockId + -> [instr] + + |