gc-map
Basic block instructions

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Vocabulary
compiler.cfg.instructions

Class description
A tuple that holds info necessary for a gc cycle to figure out where the gc root pointers are. It has the following slots:

gc-roots	sequence of vregs or spill-slots
derived-roots	An assoc of pairs of vregs or spill slots.

The 'gc-roots' and 'derived-roots' slots are initially vreg integers referencing objects that are live during the gc call and needs to be spilled so that they can be traced. In the emit-gc-map-insn word in compiler.cfg.linear-scan.assignment they are converted to spill slots which the collector is able to trace.

See also
emit-gc-info-bitmap, fill-gc-map

Definition

IN: compiler.cfg.instructions

TUPLE: gc-map gc-roots derived-roots ;