compiler.cfg.ssa.destruction.coalescing: new vocab to refactor and

[factor.git] / basis / compiler / cfg / ssa / destruction / coalescing / coalescing-docs.factor

diff --git a/basis/compiler/cfg/ssa/destruction/coalescing/coalescing-docs.factor b/basis/compiler/cfg/ssa/destruction/coalescing/coalescing-docs.factor
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+USING: compiler.cfg.instructions compiler.cfg.ssa.interference
+help.markup help.syntax kernel make sequences ;
+IN: compiler.cfg.ssa.destruction.coalescing
+
+HELP: class-element-map
+{ $var-description "Maps leaders to equivalence class elements which are sequences of " { $link vreg-info } " instances." } ;
+
+HELP: coalesce-elements
+{ $values { "merged" "??" } { "follower" "vreg" } { "leader" "vreg" } }
+{ $description "Delete follower's class, and set leaders's class to merged." } ;
+
+HELP: coalesce-insn
+{ $values { "insn" insn } }
+{ $description "Generic word supposed to be called in a " { $link make } " context which generates a list of eliminatable vreg copies. The word either eliminates copies immediately in case of " { $link ##phi } " and " { $link ##tagged>integer } " instructions or appends copies to the make sequence so that they are handled later by " { $link coalesce-cfg } "." } ;
+
+HELP: coalesce-vregs
+{ $values { "merged" "??" } { "follower" "vreg" } { "leader" "vreg" } }
+{ $description "Sets 'leader' as the leader of 'follower'." } ;
+
+HELP: try-eliminate-copy
+{ $values { "follower" "vreg" } { "leader" "vreg" } { "must?" boolean } }
+{ $description "Tries to eliminate a vreg copy from 'leader' to 'follower'. If 'must?' is " { $link t } " then a " { $link vregs-shouldn't-interfere } " error is thrown if the vregs interfere." }
+{ $see-also try-eliminate-copies vregs-interfere? } ;
+
+HELP: try-eliminate-copies
+{ $values { "pairs" "a sequence of vreg pairs" } { "must?" boolean } }
+{ $description "Tries to eliminate the vreg copies in the " { $link sequence } " 'pairs'. If 'must?' is " { $link t } " then a " { $link vregs-shouldn't-interfere } " error is thrown if any of the vregs interfere." }
+{ $see-also try-eliminate-copy } ;
+
+ARTICLE: "compiler.cfg.ssa.destruction.coalescing" "Vreg Coalescing"
+"This compiler pass eliminates redundant vreg copies."
+$nl
+"Main entry point:"
+{ $subsections coalesce-cfg }
+"Vreg copy elimination:"
+{ $subsections
+  try-eliminate-copies
+  try-eliminate-copy
+} ;