ghc-6.12.2: The GHC API Source code Contents Index

RegAlloc.Linear.Base

Description

Put common type definitions here to break recursive module dependencies.

Synopsis

type BlockAssignment = BlockMap (FreeRegs, RegMap Loc) data Loc = InReg !RealReg | InMem !StackSlot | InBoth !RealReg !StackSlot regsOfLoc :: Loc -> [RealReg] data SpillReason = SpillAlloc !Unique | SpillClobber !Unique | SpillLoad !Unique | SpillJoinRR !Unique | SpillJoinRM !Unique data RegAllocStats = RegAllocStats { ra_spillInstrs :: UniqFM [Int] } data RA_State = RA_State { ra_blockassig :: BlockAssignment ra_freeregs :: !FreeRegs ra_assig :: RegMap Loc ra_delta :: Int ra_stack :: StackMap ra_us :: UniqSupply ra_spills :: [SpillReason] } newtype RegM a = RegM { unReg :: RA_State -> (#RA_State, a#) }

Documentation

type BlockAssignment = BlockMap (FreeRegs, RegMap Loc) Source

Used to store the register assignment on entry to a basic block. We use this to handle join points, where multiple branch instructions target a particular label. We have to insert fixup code to make the register assignments from the different sources match up.

data Loc Source

Where a vreg is currently stored A temporary can be marked as living in both a register and memory (InBoth), for example if it was recently loaded from a spill location. This makes it cheap to spill (no save instruction required), but we have to be careful to turn this into InReg if the value in the register is changed. Constructors InReg !RealReg vreg is in a register InMem !StackSlot vreg is held in a stack slot InBoth !RealReg !StackSlot vreg is held in both a register and a stack slot Instances Eq Loc Ord Loc Show Loc Outputable Loc

regsOfLoc :: Loc -> [RealReg] Source

Get the reg numbers stored in this Loc.

data SpillReason Source

Reasons why instructions might be inserted by the spiller. Used when generating stats for -ddrop-asm-stats. Constructors SpillAlloc !Unique vreg was spilled to a slot so we could use its current hreg for another vreg SpillClobber !Unique vreg was moved because its hreg was clobbered SpillLoad !Unique vreg was loaded from a spill slot SpillJoinRR !Unique reg-reg move inserted during join to targets SpillJoinRM !Unique reg-mem move inserted during join to targets

data RegAllocStats Source

Used to carry interesting stats out of the register allocator. Constructors RegAllocStats ra_spillInstrs :: UniqFM [Int]

data RA_State Source

The register alloctor state Constructors RA_State ra_blockassig :: BlockAssignment the current mapping from basic blocks to the register assignments at the beginning of that block. ra_freeregs :: !FreeRegs free machine registers ra_assig :: RegMap Loc assignment of temps to locations ra_delta :: Int current stack delta ra_stack :: StackMap free stack slots for spilling ra_us :: UniqSupply unique supply for generating names for join point fixup blocks. ra_spills :: [SpillReason] Record why things were spilled, for -ddrop-asm-stats. Just keep a list here instead of a map of regs -> reasons. We don't want to slow down the allocator if we're not going to emit the stats.

newtype RegM a Source

The register allocator monad type. Constructors RegM unReg :: RA_State -> (#RA_State, a#) Instances Monad RegM

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