GHC.CmmToAsm.Reg.Linear.Base

Put common type definitions here to break recursive module dependencies.

Documentation

data BlockAssignment freeRegs

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.

lookupBlockAssignment :: BlockId -> BlockAssignment freeRegs -> Maybe (freeRegs, RegMap Loc)

Find the register mapping for a specific BlockId.

lookupFirstUsed :: VirtualReg -> BlockAssignment freeRegs -> Maybe RealReg

Lookup which register a virtual register was first assigned to.

emptyBlockAssignment :: BlockAssignment freeRegs

An initial empty BlockAssignment

updateBlockAssignment :: BlockId -> (freeRegs, RegMap Loc) -> BlockAssignment freeRegs -> BlockAssignment freeRegs

Add new register mappings for a specific block.

data Loc

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

Outputable Loc

Defined in GHC.CmmToAsm.Reg.Linear.Base

Methods

ppr :: Loc -> SDoc

Show Loc

Defined in GHC.CmmToAsm.Reg.Linear.Base

Methods

showsPrec :: Int -> Loc -> ShowS

show :: Loc -> String

showList :: [Loc] -> ShowS

Eq Loc

Defined in GHC.CmmToAsm.Reg.Linear.Base

Methods

(==) :: Loc -> Loc -> Bool

(/=) :: Loc -> Loc -> Bool

Ord Loc

Defined in GHC.CmmToAsm.Reg.Linear.Base

Methods

compare :: Loc -> Loc -> Ordering

(<) :: Loc -> Loc -> Bool

(<=) :: Loc -> Loc -> Bool

(>) :: Loc -> Loc -> Bool

(>=) :: Loc -> Loc -> Bool

max :: Loc -> Loc -> Loc

min :: Loc -> Loc -> Loc

regsOfLoc :: Loc -> [RealReg]

Get the reg numbers stored in this Loc.

data SpillReason

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

Used to carry interesting stats out of the register allocator.

Constructors

RegAllocStats

Fields

• ra_spillInstrs :: UniqFM Unique [Int]
• ra_fixupList :: [(BlockId, BlockId, BlockId)]

  (from,fixup,to) : We inserted fixup code between from and to

data RA_State freeRegs

The register allocator state

Constructors

RA_State

Fields

• ra_blockassig :: BlockAssignment freeRegs

  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.

• ra_config :: !NCGConfig

  Native code generator configuration

• ra_fixups :: [(BlockId, BlockId, BlockId)]

  (from,fixup,to) : We inserted fixup code between from and to