factor: trim using lists

[factor.git] / extra / compiler / cfg / gvn / avail / avail.factor

diff --git a/extra/compiler/cfg/gvn/avail/avail.factor b/extra/compiler/cfg/gvn/avail/avail.factor
index 906646281cff2ade93ed94bc06380c3e5806ec90..c72cbc51d75e905434371576dca86f8fe304c9cd 100644 (file)
--- a/extra/compiler/cfg/gvn/avail/avail.factor
+++ b/extra/compiler/cfg/gvn/avail/avail.factor
@@ -1,15 +1,9 @@
 ! Copyright (C) 2011 Alex Vondrak.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: accessors assocs hashtables kernel namespaces sequences
-sequences.extras sets
-compiler.cfg
-compiler.cfg.dataflow-analysis
-compiler.cfg.def-use
-compiler.cfg.gvn.graph
-compiler.cfg.predecessors
-compiler.cfg.renaming.functor
-compiler.cfg.rpo
-compiler.utilities ;
+USING: accessors assocs compiler.cfg
+compiler.cfg.dataflow-analysis compiler.cfg.def-use
+compiler.cfg.gvn.graph compiler.cfg.renaming.functor
+compiler.utilities hashtables kernel namespaces sequences ;
 IN: compiler.cfg.gvn.avail
 
 : defined ( bb -- vregs )
@@ -24,9 +18,12 @@ M: avail transfer-set drop defined assoc-union ;
 
 : available? ( vn -- ? ) basic-block get avail-in key? ;
 
+: best-vreg ( available-vregs -- vreg )
+    [ f ] [ infimum ] if-empty ;
+
 : >avail-vreg ( vreg -- vreg/f )
     final-iteration? get [
-        congruence-class [ available? ] filter ?infimum
+        congruence-class [ available? ] filter best-vreg
     ] when ;
 
 : available-uses? ( insn -- ? )