compiler.cfg.gvn.misc: simplify ##phi rewrite

diff --git a/extra/compiler/cfg/gvn/expressions/expressions.factor b/extra/compiler/cfg/gvn/expressions/expressions.factor
index e87fe66d891c775f6512536d42cc99c587bf5bd8..c656d4ccc078941e2b29464cc1bf69232f92177b 100644 (file)
--- a/extra/compiler/cfg/gvn/expressions/expressions.factor
+++ b/extra/compiler/cfg/gvn/expressions/expressions.factor
@@ -84,5 +84,8 @@ M: ##load-integer >expr val>> <integer-expr> ;
 
 M: ##load-reference >expr obj>> <reference-expr> ;
 
+! TODO experiment with sorting, in case that identifies more
+! phi equivalences
+
 M: ##phi >expr
     inputs>> values [ vreg>vn ] map \ ##phi prefix ;

diff --git a/extra/compiler/cfg/gvn/misc/misc.factor b/extra/compiler/cfg/gvn/misc/misc.factor
index 864af7b0b57912656956d2027b5d6241e7ef6c35..9e23ae3bdd2aa6b10efc9f3444364b861cc3fba5 100644 (file)
--- a/extra/compiler/cfg/gvn/misc/misc.factor
+++ b/extra/compiler/cfg/gvn/misc/misc.factor
@@ -16,10 +16,8 @@ M: ##replace rewrite
     ] [ 2drop f ] if ;
 
 M: ##phi rewrite
-    [ dst>> ] [ inputs>> values [ vreg>vn ] map ] bi
-    dup sift
+    [ dst>> ] [ inputs>> values [ vreg>vn ] map sift ] bi
     dup all-equal? [
-        nip
         [ drop f ]
         [ first <copy> ] if-empty
-    ] [ 3drop f ] if ;
+    ] [ 2drop f ] if ;