vreg>reg ( vreg -- reg/spill-slot )
Assigning registers to live intervals

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Vocabulary
compiler.cfg.linear-scan.assignment

Inputs

vreg	virtual register

Outputs

reg/spill-slot

a register or a spill slot

Word description
Translates a virtual register to a physical one. If the vreg is not in the pending set, then it must have been spilled and its spill slot is returned.

Errors
Can throw a bad-vreg error if the vreg is not in the pending-interval-assoc and also doesn't have a spill slot registered.

See also
lookup-spill-slot, pending-interval-assoc

Definition

USING: assocs compiler.cfg.linear-scan.allocation.state
compiler.cfg.registers compiler.cfg.ssa.destruction.leaders
kernel namespaces ;

IN: compiler.cfg.linear-scan.assignment

: vreg>reg ( vreg -- reg/spill-slot )
    dup leader dup pending-interval-assoc get at
    [ 2nip ] [ swap rep-of lookup-spill-slot ] if* ;