     ] when ;
 
 : rewrite-redundant-comparison? ( insn -- ? )
-    [ src1>> vreg>expr compare-expr? ]
-    [ src2>> \ f tag-number = ]
-    [ cc>> { cc= cc/= } memq? ]
-    tri and and ; inline
+    {
+        [ src1>> vreg>expr compare-expr? ]
+        [ src2>> \ f tag-number = ]
+        [ cc>> { cc= cc/= } memq? ]
+    } 1&& ; inline
 
 : rewrite-redundant-comparison ( insn -- insn' )
     [ cc>> ] [ dst>> ] [ src1>> vreg>expr dup op>> ] tri {


: rewrite-tagged-comparison? ( insn -- ? )
    #! Are we comparing two tagged fixnums? Then untag them.
    [ src1>> vreg>expr tag-fixnum-expr? ]
    [ src2>> tag-mask get bitand 0 = ]
    bi and ; inline

: (rewrite-tagged-comparison) ( insn -- src1 src2 cc )
    [ src1>> vreg>expr in1>> vn>vreg ]


: ##branch-t? ( insn -- ? )
    dup ##compare-imm-branch? [
        {
            [ cc>> cc/= eq? ]
            [ src2>> \ f tag-number eq? ]
        } 1&&
    ] [ drop f ] if ; inline

: rewrite-boolean-comparison? ( insn -- ? )
