Documentation

type BlockAssignment freeRegs = 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
Fields ra_spillInstrs :: UniqFM [Int]

data RA_State freeRegs Source

The register alloctor 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.

newtype RegM freeRegs a Source

The register allocator monad type.

Constructors

RegM
Fields unReg :: RA_State freeRegs -> (#RA_State freeRegs, a#)

Instances

Monad (RegM freeRegs)

The RegM Monad