diff --git a/basis/compiler/cfg/alias-analysis/alias-analysis.factor b/basis/compiler/cfg/alias-analysis/alias-analysis.factor
index 4a2f2bf9aa..ba2caa1e71 100644
--- a/basis/compiler/cfg/alias-analysis/alias-analysis.factor
+++ b/basis/compiler/cfg/alias-analysis/alias-analysis.factor
@@ -9,6 +9,7 @@ compiler.cfg.def-use
 compiler.cfg.liveness
 compiler.cfg.copy-prop
 compiler.cfg.registers
+compiler.cfg.utilities
 compiler.cfg.comparisons
 compiler.cfg.instructions
 compiler.cfg.representations.preferred ;
@@ -245,11 +246,10 @@ M: ##allocation analyze-aliases*
 M: ##read analyze-aliases*
     call-next-method
     dup [ dst>> ] [ insn-slot# ] [ insn-object ] tri
-    2dup live-slot dup [
-        2nip any-rep \ ##copy new-insn analyze-aliases* nip
-    ] [
-        drop remember-slot
-    ] if ;
+    2dup live-slot dup
+    [ 2nip <copy> analyze-aliases* nip ]
+    [ drop remember-slot ]
+    if ;
 
 : idempotent? ( value slot#/f vreg -- ? )
     #! Are we storing a value back to the same slot it was read
diff --git a/basis/compiler/cfg/instructions/instructions.factor b/basis/compiler/cfg/instructions/instructions.factor
index 184e4076a3..3a4de986ad 100644
--- a/basis/compiler/cfg/instructions/instructions.factor
+++ b/basis/compiler/cfg/instructions/instructions.factor
@@ -96,7 +96,7 @@ use: obj/tagged-rep index/int-rep
 temp: temp/int-rep ;
 
 ! Register transfers
-PURE-INSN: ##copy
+INSN: ##copy
 def: dst
 use: src
 literal: rep ;
diff --git a/basis/compiler/cfg/utilities/utilities.factor b/basis/compiler/cfg/utilities/utilities.factor
index bee2226ec4..de2d238f1e 100644
--- a/basis/compiler/cfg/utilities/utilities.factor
+++ b/basis/compiler/cfg/utilities/utilities.factor
@@ -1,4 +1,4 @@
-! Copyright (C) 2008, 2009 Slava Pestov.
+! Copyright (C) 2008, 2010 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors assocs combinators combinators.short-circuit
 cpu.architecture kernel layouts locals make math namespaces sequences
@@ -79,3 +79,5 @@ SYMBOL: visited
 : predecessor ( bb -- pred )
     predecessors>> first ; inline
 
+: <copy> ( dst src -- insn )
+    any-rep \ ##copy new-insn ;
diff --git a/basis/compiler/cfg/value-numbering/alien/alien.factor b/basis/compiler/cfg/value-numbering/alien/alien.factor
index 5b9b72f1ab..9fc1405f6c 100644
--- a/basis/compiler/cfg/value-numbering/alien/alien.factor
+++ b/basis/compiler/cfg/value-numbering/alien/alien.factor
@@ -2,14 +2,20 @@
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors combinators combinators.short-circuit fry
 kernel make math sequences
+cpu.architecture
 compiler.cfg.hats
-compiler.cfg.instructions
+compiler.cfg.utilities
 compiler.cfg.registers
+compiler.cfg.instructions
 compiler.cfg.value-numbering.expressions
 compiler.cfg.value-numbering.graph
 compiler.cfg.value-numbering.rewrite ;
 IN: compiler.cfg.value-numbering.alien
 
+M: ##box-displaced-alien rewrite
+    dup displacement>> vreg>expr expr-zero?
+    [ [ dst>> ] [ base>> ] bi <copy> ] [ drop f ] if ;
+
 ! ##box-displaced-alien f 1 2 3 <class>
 ! ##unbox-c-ptr 4 1 <class>
 ! =>
@@ -17,6 +23,9 @@ IN: compiler.cfg.value-numbering.alien
 ! ##unbox-c-ptr 5 3 <class>
 ! ##add 4 5 2
 
+: rewrite-unbox-alien ( insn expr -- insn )
+    [ dst>> ] [ src>> vn>vreg ] bi* <copy> ;
+
 : rewrite-unbox-displaced-alien ( insn expr -- insns )
     [
         [ dst>> ]
@@ -25,9 +34,17 @@ IN: compiler.cfg.value-numbering.alien
         ##add
     ] { } make ;
 
-M: ##unbox-any-c-ptr rewrite
-    dup src>> vreg>expr dup box-displaced-alien-expr?
-    [ rewrite-unbox-displaced-alien ] [ 2drop f ] if ;
+: rewrite-unbox-any-c-ptr ( insn -- insn/f )
+    dup src>> vreg>expr
+    {
+        { [ dup box-alien-expr? ] [ rewrite-unbox-alien ] }
+        { [ dup box-displaced-alien-expr? ] [ rewrite-unbox-displaced-alien ] }
+        [ 2drop f ]
+    } cond ;
+
+M: ##unbox-any-c-ptr rewrite rewrite-unbox-any-c-ptr ;
+
+M: ##unbox-alien rewrite rewrite-unbox-any-c-ptr ;
 
 ! Fuse ##add-imm into ##load-memory(-imm) and ##store-memory(-imm)
 ! just update the offset in the instruction
diff --git a/basis/compiler/cfg/value-numbering/comparisons/comparisons.factor b/basis/compiler/cfg/value-numbering/comparisons/comparisons.factor
index cd2f420af9..43a04a999b 100644
--- a/basis/compiler/cfg/value-numbering/comparisons/comparisons.factor
+++ b/basis/compiler/cfg/value-numbering/comparisons/comparisons.factor
@@ -3,9 +3,11 @@
 USING: accessors combinators kernel math math.order namespaces
 sequences vectors combinators.short-circuit compiler.cfg
 compiler.cfg.comparisons compiler.cfg.instructions
-compiler.cfg.registers compiler.cfg.value-numbering.expressions
+compiler.cfg.registers
+compiler.cfg.value-numbering.math
 compiler.cfg.value-numbering.graph
-compiler.cfg.value-numbering.rewrite ;
+compiler.cfg.value-numbering.rewrite
+compiler.cfg.value-numbering.expressions ;
 IN: compiler.cfg.value-numbering.comparisons
 
 ! Optimizations performed here:
@@ -127,9 +129,6 @@ M: ##compare-integer-imm-branch rewrite
     [ vreg>integer ] dip
     \ ##compare-integer-imm-branch new-insn ; inline
 
-: self-compare? ( insn -- ? )
-    [ src1>> ] [ src2>> ] bi [ vreg>vn ] bi@ = ; inline
-
 : evaluate-self-compare ( insn -- ? )
     cc>> { cc= cc<= cc>= } member-eq? ;
 
@@ -140,7 +139,7 @@ M: ##compare-branch rewrite
     {
         { [ dup src1>> vreg-immediate-comparand? ] [ t >compare-imm-branch ] }
         { [ dup src2>> vreg-immediate-comparand? ] [ f >compare-imm-branch ] }
-        { [ dup self-compare? ] [ rewrite-self-compare-branch ] }
+        { [ dup diagonal? ] [ rewrite-self-compare-branch ] }
         [ drop f ]
     } cond ;
 
@@ -148,7 +147,7 @@ M: ##compare-integer-branch rewrite
     {
         { [ dup src1>> vreg-immediate-arithmetic? ] [ t >compare-integer-imm-branch ] }
         { [ dup src2>> vreg-immediate-arithmetic? ] [ f >compare-integer-imm-branch ] }
-        { [ dup self-compare? ] [ rewrite-self-compare-branch ] }
+        { [ dup diagonal? ] [ rewrite-self-compare-branch ] }
         [ drop f ]
     } cond ;
 
@@ -176,7 +175,7 @@ M: ##compare rewrite
     {
         { [ dup src1>> vreg-immediate-comparand? ] [ t >compare-imm ] }
         { [ dup src2>> vreg-immediate-comparand? ] [ f >compare-imm ] }
-        { [ dup self-compare? ] [ rewrite-self-compare ] }
+        { [ dup diagonal? ] [ rewrite-self-compare ] }
         [ drop f ]
     } cond ;
 
@@ -184,7 +183,7 @@ M: ##compare-integer rewrite
     {
         { [ dup src1>> vreg-immediate-arithmetic? ] [ t >compare-integer-imm ] }
         { [ dup src2>> vreg-immediate-arithmetic? ] [ f >compare-integer-imm ] }
-        { [ dup self-compare? ] [ rewrite-self-compare ] }
+        { [ dup diagonal? ] [ rewrite-self-compare ] }
         [ drop f ]
     } cond ;
 
diff --git a/basis/compiler/cfg/value-numbering/expressions/expressions.factor b/basis/compiler/cfg/value-numbering/expressions/expressions.factor
index 041432c089..78097b1635 100644
--- a/basis/compiler/cfg/value-numbering/expressions/expressions.factor
+++ b/basis/compiler/cfg/value-numbering/expressions/expressions.factor
@@ -14,6 +14,10 @@ TUPLE: integer-expr < expr value ;
 
 C: <integer-expr> integer-expr
 
+: expr-zero? ( expr -- ? ) T{ integer-expr f 0 } = ; inline
+: expr-one? ( expr -- ? ) T{ integer-expr f 1 } = ; inline
+: expr-neg-one? ( expr -- ? ) T{ integer-expr f -1 } = ; inline
+
 TUPLE: reference-expr < expr value ;
 
 C: <reference-expr> reference-expr
@@ -34,6 +38,8 @@ GENERIC: >expr ( insn -- expr )
 
 M: insn >expr drop next-input-expr ;
 
+M: ##copy >expr "Fail" throw ;
+
 M: ##load-integer >expr val>> <integer-expr> ;
 
 M: ##load-reference >expr obj>> <reference-expr> ;
diff --git a/basis/compiler/cfg/value-numbering/math/math.factor b/basis/compiler/cfg/value-numbering/math/math.factor
index 742e995f1d..498ca946f5 100644
--- a/basis/compiler/cfg/value-numbering/math/math.factor
+++ b/basis/compiler/cfg/value-numbering/math/math.factor
@@ -3,11 +3,11 @@
 USING: accessors combinators cpu.architecture fry kernel layouts
 locals make math sequences compiler.cfg.instructions
 compiler.cfg.registers
+compiler.cfg.utilities
 compiler.cfg.value-numbering.expressions
 compiler.cfg.value-numbering.folding
 compiler.cfg.value-numbering.graph
-compiler.cfg.value-numbering.rewrite
-compiler.cfg.value-numbering.simplify ;
+compiler.cfg.value-numbering.rewrite ;
 IN: compiler.cfg.value-numbering.math
 
 : f-expr? ( expr -- ? ) T{ reference-expr f f } = ;
@@ -19,11 +19,25 @@ M: ##tagged>integer rewrite
         [ 2drop f ]
     } cond ;
 
+: self-inverse ( insn -- insn' )
+    [ dst>> ] [ src>> vreg>expr src>> vn>vreg ] bi <copy> ;
+
+: identity ( insn -- insn' )
+    [ dst>> ] [ src1>> ] bi <copy> ;
+
 M: ##neg rewrite
-    dup unary-constant-fold? [ unary-constant-fold ] [ drop f ] if ;
+    {
+        { [ dup src>> vreg>expr neg-expr? ] [ self-inverse ] }
+        { [ dup unary-constant-fold? ] [ unary-constant-fold ] }
+        [ drop f ]
+    } cond ;
 
 M: ##not rewrite
-    dup unary-constant-fold? [ unary-constant-fold ] [ drop f ] if ;
+    {
+        { [ dup src>> vreg>expr not-expr? ] [ self-inverse ] }
+        { [ dup unary-constant-fold? ] [ unary-constant-fold ] }
+        [ drop f ]
+    } cond ;
 
 ! Reassociation converts
 ! ## *-imm 2 1 X
@@ -56,20 +70,18 @@ M: ##not rewrite
 
 M: ##add-imm rewrite
     {
+        { [ dup src2>> 0 = ] [ identity ] }
         { [ dup binary-constant-fold? ] [ binary-constant-fold ] }
         { [ dup src1>> vreg>expr add-imm-expr? ] [ \ ##add-imm reassociate-arithmetic ] }
         [ drop f ]
     } cond ;
 
 : sub-imm>add-imm ( insn -- insn' )
-    [ dst>> ] [ src1>> ] [ src2>> neg ] tri dup immediate-arithmetic?
+    [ dst>> ] [ src1>> ] [ src2>> neg ] tri
+    dup immediate-arithmetic?
     \ ##add-imm ?new-insn ;
 
-M: ##sub-imm rewrite
-    {
-        { [ dup binary-constant-fold? ] [ binary-constant-fold ] }
-        [ sub-imm>add-imm ]
-    } cond ;
+M: ##sub-imm rewrite sub-imm>add-imm ;
 
 ! Convert ##mul-imm -1 => ##neg
 : mul-to-neg? ( insn -- ? )
@@ -129,11 +141,15 @@ M: ##and-imm rewrite
     {
         { [ dup binary-constant-fold? ] [ binary-constant-fold ] }
         { [ dup src1>> vreg>expr and-imm-expr? ] [ \ ##and-imm reassociate-bitwise ] }
+        { [ dup src2>> 0 = ] [ dst>> 0 \ ##load-integer new-insn ] }
+        { [ dup src2>> -1 = ] [ identity ] }
         [ drop f ]
     } cond ;
 
 M: ##or-imm rewrite
     {
+        { [ dup src2>> 0 = ] [ identity ] }
+        { [ dup src2>> -1 = ] [ dst>> -1 \ ##load-integer new-insn ] }
         { [ dup binary-constant-fold? ] [ binary-constant-fold ] }
         { [ dup src1>> vreg>expr or-imm-expr? ] [ \ ##or-imm reassociate-bitwise ] }
         [ drop f ]
@@ -141,6 +157,8 @@ M: ##or-imm rewrite
 
 M: ##xor-imm rewrite
     {
+        { [ dup src2>> 0 = ] [ identity ] }
+        { [ dup src2>> -1 = ] [ [ dst>> ] [ src1>> ] bi \ ##not new-insn ] }
         { [ dup binary-constant-fold? ] [ binary-constant-fold ] }
         { [ dup src1>> vreg>expr xor-imm-expr? ] [ \ ##xor-imm reassociate-bitwise ] }
         [ drop f ]
@@ -148,6 +166,7 @@ M: ##xor-imm rewrite
 
 M: ##shl-imm rewrite
     {
+        { [ dup src2>> 0 = ] [ identity ] }
         { [ dup binary-constant-fold? ] [ binary-constant-fold ] }
         { [ dup src1>> vreg>expr shl-imm-expr? ] [ \ ##shl-imm reassociate-shift ] }
         { [ dup distribute-over-add? ] [ \ ##add-imm \ ##shl-imm distribute ] }
@@ -157,6 +176,7 @@ M: ##shl-imm rewrite
 
 M: ##shr-imm rewrite
     {
+        { [ dup src2>> 0 = ] [ identity ] }
         { [ dup binary-constant-fold? ] [ binary-constant-fold ] }
         { [ dup src1>> vreg>expr shr-imm-expr? ] [ \ ##shr-imm reassociate-shift ] }
         [ drop f ]
@@ -164,6 +184,7 @@ M: ##shr-imm rewrite
 
 M: ##sar-imm rewrite
     {
+        { [ dup src2>> 0 = ] [ identity ] }
         { [ dup binary-constant-fold? ] [ binary-constant-fold ] }
         { [ dup src1>> vreg>expr sar-imm-expr? ] [ \ ##sar-imm reassociate-shift ] }
         [ drop f ]
@@ -187,10 +208,10 @@ M: ##add rewrite
         [ drop f ]
     } cond ;
 
-! ##sub 2 1 1 => ##load-integer 2 0
-: subtraction-identity? ( insn -- ? )
-    [ src1>> ] [ src2>> ] bi [ vreg>vn ] bi@ eq? ;
+: diagonal? ( insn -- ? )
+    [ src1>> vreg>vn ] [ src2>> vreg>vn ] bi = ; inline
 
+! ##sub 2 1 1 => ##load-integer 2 0
 : rewrite-subtraction-identity ( insn -- insn' )
     dst>> 0 \ ##load-integer new-insn ;
 
@@ -207,7 +228,7 @@ M: ##add rewrite
 M: ##sub rewrite
     {
         { [ dup sub-to-neg? ] [ sub-to-neg ] }
-        { [ dup subtraction-identity? ] [ rewrite-subtraction-identity ] }
+        { [ dup diagonal? ] [ rewrite-subtraction-identity ] }
         { [ dup src2>> vreg-immediate-arithmetic? ] [ \ ##sub-imm f insn>imm-insn ] }
         [ drop f ]
     } cond ;
@@ -221,6 +242,7 @@ M: ##mul rewrite
 
 M: ##and rewrite
     {
+        { [ dup diagonal? ] [ identity ] }
         { [ dup src2>> vreg-immediate-bitwise? ] [ \ ##and-imm f insn>imm-insn ] }
         { [ dup src1>> vreg-immediate-bitwise? ] [ \ ##and-imm t insn>imm-insn ] }
         [ drop f ]
@@ -228,6 +250,7 @@ M: ##and rewrite
 
 M: ##or rewrite
     {
+        { [ dup diagonal? ] [ identity ] }
         { [ dup src2>> vreg-immediate-bitwise? ] [ \ ##or-imm f insn>imm-insn ] }
         { [ dup src1>> vreg-immediate-bitwise? ] [ \ ##or-imm t insn>imm-insn ] }
         [ drop f ]
@@ -235,6 +258,7 @@ M: ##or rewrite
 
 M: ##xor rewrite
     {
+        { [ dup diagonal? ] [ dst>> 0 \ ##load-integer new-insn ] }
         { [ dup src2>> vreg-immediate-bitwise? ] [ \ ##xor-imm f insn>imm-insn ] }
         { [ dup src1>> vreg-immediate-bitwise? ] [ \ ##xor-imm t insn>imm-insn ] }
         [ drop f ]
diff --git a/basis/compiler/cfg/value-numbering/simd/simd.factor b/basis/compiler/cfg/value-numbering/simd/simd.factor
index d37d16896b..940e0d5acb 100644
--- a/basis/compiler/cfg/value-numbering/simd/simd.factor
+++ b/basis/compiler/cfg/value-numbering/simd/simd.factor
@@ -7,19 +7,22 @@ vectors locals make alien.c-types io.binary grouping
 math.vectors.simd.intrinsics
 compiler.cfg
 compiler.cfg.registers
+compiler.cfg.utilities
 compiler.cfg.comparisons
 compiler.cfg.instructions
 compiler.cfg.value-numbering.alien
 compiler.cfg.value-numbering.expressions
 compiler.cfg.value-numbering.graph
-compiler.cfg.value-numbering.rewrite
-compiler.cfg.value-numbering.simplify ;
+compiler.cfg.value-numbering.rewrite ;
 IN: compiler.cfg.value-numbering.simd
 
 ! Some lame constant folding for SIMD intrinsics. Eventually this
 ! should be redone completely.
 
-: rewrite-shuffle-vector-imm ( insn expr -- insn' )
+: useless-shuffle-vector-imm? ( insn -- ? )
+    [ shuffle>> ] [ rep>> rep-length iota ] bi sequence= ;
+
+: compose-shuffle-vector-imm ( insn expr -- insn' )
     2dup [ rep>> ] bi@ eq? [
         [ [ dst>> ] [ src>> vn>vreg ] bi* ]
         [ [ shuffle>> ] bi@ nths ]
@@ -36,7 +39,8 @@ IN: compiler.cfg.value-numbering.simd
 
 M: ##shuffle-vector-imm rewrite
     dup src>> vreg>expr {
-        { [ dup shuffle-vector-imm-expr? ] [ rewrite-shuffle-vector-imm ] }
+        { [ over useless-shuffle-vector-imm? ] [ drop [ dst>> ] [ src>> ] bi <copy> ] }
+        { [ dup shuffle-vector-imm-expr? ] [ compose-shuffle-vector-imm ] }
         { [ dup reference-expr? ] [ fold-shuffle-vector-imm ] }
         [ 2drop f ]
     } cond ;
@@ -53,8 +57,11 @@ M: ##shuffle-vector-imm rewrite
     } case ;
 
 M: ##scalar>vector rewrite
-    dup src>> vreg>expr dup reference-expr?
-    [ fold-scalar>vector ] [ 2drop f ] if ;
+    dup src>> vreg>expr {
+        { [ dup reference-expr? ] [ fold-scalar>vector ] }
+        { [ dup vector>scalar-expr? ] [ [ dst>> ] [ src>> ] bi* <copy> ] }
+        [ 2drop f ]
+    } cond ;
 
 M: ##xor-vector rewrite
     dup [ src1>> vreg>vn ] [ src2>> vreg>vn ] bi eq?
@@ -104,13 +111,3 @@ M: ##andn-vector rewrite
             [ rep>> ]
         } cleave \ ##and-vector new-insn
     ] [ drop f ] if ;
-
-M: scalar>vector-expr simplify*
-    src>> vn>expr {
-        { [ dup vector>scalar-expr? ] [ src>> ] }
-        [ drop f ]
-    } cond ;
-
-M: shuffle-vector-imm-expr simplify*
-    [ src>> ] [ shuffle>> ] [ rep>> rep-length iota ] tri
-    sequence= [ drop f ] unless ;
diff --git a/basis/compiler/cfg/value-numbering/simplify/simplify.factor b/basis/compiler/cfg/value-numbering/simplify/simplify.factor
deleted file mode 100644
index 67203a9ca7..0000000000
--- a/basis/compiler/cfg/value-numbering/simplify/simplify.factor
+++ /dev/null
@@ -1,136 +0,0 @@
-! Copyright (C) 2008, 2010 Slava Pestov.
-! See http://factorcode.org/license.txt for BSD license.
-USING: kernel accessors combinators classes math layouts
-sequences 
-compiler.cfg.instructions
-compiler.cfg.value-numbering.graph
-compiler.cfg.value-numbering.expressions ;
-IN: compiler.cfg.value-numbering.simplify
-
-! Return value of f means we didn't simplify.
-GENERIC: simplify* ( expr -- vn/expr/f )
-
-M: copy-expr simplify* src>> ;
-
-: simplify-unbox-alien ( expr -- vn/expr/f )
-    src>> vn>expr dup box-alien-expr? [ src>> ] [ drop f ] if ;
-
-M: unbox-alien-expr simplify* simplify-unbox-alien ;
-
-M: unbox-any-c-ptr-expr simplify* simplify-unbox-alien ;
-
-: expr-zero? ( expr -- ? ) T{ integer-expr f 0 } = ; inline
-: expr-one? ( expr -- ? ) T{ integer-expr f 1 } = ; inline
-: expr-neg-one? ( expr -- ? ) T{ integer-expr f -1 } = ; inline
-
-: >unary-expr< ( expr -- in ) src>> vn>expr ; inline
-
-M: neg-expr simplify*
-    >unary-expr< {
-        { [ dup neg-expr? ] [ src>> ] }
-        [ drop f ]
-    } cond ;
-
-M: not-expr simplify*
-    >unary-expr< {
-        { [ dup not-expr? ] [ src>> ] }
-        [ drop f ]
-    } cond ;
-
-: >binary-expr< ( expr -- in1 in2 )
-    [ src1>> vn>expr ] [ src2>> vn>expr ] bi ; inline
-
-: simplify-add ( expr -- vn/expr/f )
-    >binary-expr< {
-        { [ over expr-zero? ] [ nip ] }
-        { [ dup expr-zero? ] [ drop ] }
-        [ 2drop f ]
-    } cond ; inline
-
-M: add-expr simplify* simplify-add ;
-M: add-imm-expr simplify* simplify-add ;
-
-: simplify-sub ( expr -- vn/expr/f )
-    >binary-expr< {
-        { [ dup expr-zero? ] [ drop ] }
-        [ 2drop f ]
-    } cond ; inline
-
-M: sub-expr simplify* simplify-sub ;
-M: sub-imm-expr simplify* simplify-sub ;
-
-: simplify-mul ( expr -- vn/expr/f )
-    >binary-expr< {
-        { [ over expr-one? ] [ drop ] }
-        { [ dup expr-one? ] [ drop ] }
-        [ 2drop f ]
-    } cond ; inline
-
-M: mul-expr simplify* simplify-mul ;
-M: mul-imm-expr simplify* simplify-mul ;
-
-: simplify-and ( expr -- vn/expr/f )
-    >binary-expr< {
-        { [ 2dup eq? ] [ drop ] }
-        [ 2drop f ]
-    } cond ; inline
-
-M: and-expr simplify* simplify-and ;
-M: and-imm-expr simplify* simplify-and ;
-
-: simplify-or ( expr -- vn/expr/f )
-    >binary-expr< {
-        { [ 2dup eq? ] [ drop ] }
-        { [ over expr-zero? ] [ nip ] }
-        { [ dup expr-zero? ] [ drop ] }
-        [ 2drop f ]
-    } cond ; inline
-
-M: or-expr simplify* simplify-or ;
-M: or-imm-expr simplify* simplify-or ;
-
-: simplify-xor ( expr -- vn/expr/f )
-    >binary-expr< {
-        { [ over expr-zero? ] [ nip ] }
-        { [ dup expr-zero? ] [ drop ] }
-        [ 2drop f ]
-    } cond ; inline
-
-M: xor-expr simplify* simplify-xor ;
-M: xor-imm-expr simplify* simplify-xor ;
-
-: simplify-shr ( expr -- vn/expr/f )
-    >binary-expr< {
-        { [ dup expr-zero? ] [ drop ] }
-        [ 2drop f ]
-    } cond ; inline
-
-M: shr-expr simplify* simplify-shr ;
-M: shr-imm-expr simplify* simplify-shr ;
-
-: simplify-shl ( expr -- vn/expr/f )
-    >binary-expr< {
-        { [ dup expr-zero? ] [ drop ] }
-        [ 2drop f ]
-    } cond ; inline
-
-M: shl-expr simplify* simplify-shl ;
-M: shl-imm-expr simplify* simplify-shl ;
-
-M: box-displaced-alien-expr simplify*
-    [ base>> ] [ displacement>> ] bi {
-        { [ dup vn>expr expr-zero? ] [ drop ] }
-        [ 2drop f ]
-    } cond ;
-
-M: expr simplify* drop f ;
-
-: simplify ( expr -- vn )
-    dup simplify* {
-        { [ dup not ] [ drop expr>vn ] }
-        { [ dup expr? ] [ expr>vn nip ] }
-        { [ dup integer? ] [ nip ] }
-    } cond ;
-
-: number-values ( insn -- )
-    [ >expr simplify ] [ dst>> ] bi set-vn ;
diff --git a/basis/compiler/cfg/value-numbering/simplify/summary.txt b/basis/compiler/cfg/value-numbering/simplify/summary.txt
deleted file mode 100644
index 1027c83ce4..0000000000
--- a/basis/compiler/cfg/value-numbering/simplify/summary.txt
+++ /dev/null
@@ -1 +0,0 @@
-Algebraic simplification of expressions
diff --git a/basis/compiler/cfg/value-numbering/value-numbering-tests.factor b/basis/compiler/cfg/value-numbering/value-numbering-tests.factor
index 851f096ea3..0c9d386544 100644
--- a/basis/compiler/cfg/value-numbering/value-numbering-tests.factor
+++ b/basis/compiler/cfg/value-numbering/value-numbering-tests.factor
@@ -392,6 +392,20 @@ cpu x86.32? [
     } value-numbering-step
 ] unit-test
 
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##neg f 1 0 }
+        T{ ##copy f 2 0 any-rep }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##neg f 1 0 }
+        T{ ##neg f 2 1 }
+    } value-numbering-step
+] unit-test
+
 [
     {
         T{ ##peek f 0 D 0 }
@@ -727,6 +741,20 @@ cpu x86.32? [
     } value-numbering-step
 ] unit-test
 
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##copy f 1 0 any-rep }
+        T{ ##load-reference f 2 f }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##copy f 1 0 any-rep }
+        T{ ##compare-integer f 2 0 1 cc< }
+    } value-numbering-step
+] unit-test
+
 [
     {
         T{ ##peek f 0 D 0 }
@@ -1314,7 +1342,6 @@ cpu x86.32? [
     {
         T{ ##peek f 0 D 0 }
         T{ ##peek f 1 D 1 }
-        T{ ##load-integer f 2 0 }
         T{ ##copy f 3 0 any-rep }
         T{ ##replace f 3 D 0 }
     }
@@ -1322,8 +1349,7 @@ cpu x86.32? [
     {
         T{ ##peek f 0 D 0 }
         T{ ##peek f 1 D 1 }
-        T{ ##sub f 2 1 1 }
-        T{ ##add f 3 0 2 }
+        T{ ##add-imm f 3 0 0 }
         T{ ##replace f 3 D 0 }
     } value-numbering-step
 ] unit-test
@@ -1332,7 +1358,6 @@ cpu x86.32? [
     {
         T{ ##peek f 0 D 0 }
         T{ ##peek f 1 D 1 }
-        T{ ##load-integer f 2 0 }
         T{ ##copy f 3 0 any-rep }
         T{ ##replace f 3 D 0 }
     }
@@ -1340,8 +1365,7 @@ cpu x86.32? [
     {
         T{ ##peek f 0 D 0 }
         T{ ##peek f 1 D 1 }
-        T{ ##sub f 2 1 1 }
-        T{ ##sub f 3 0 2 }
+        T{ ##or-imm f 3 0 0 }
         T{ ##replace f 3 D 0 }
     } value-numbering-step
 ] unit-test
@@ -1350,7 +1374,6 @@ cpu x86.32? [
     {
         T{ ##peek f 0 D 0 }
         T{ ##peek f 1 D 1 }
-        T{ ##load-integer f 2 0 }
         T{ ##copy f 3 0 any-rep }
         T{ ##replace f 3 D 0 }
     }
@@ -1358,8 +1381,7 @@ cpu x86.32? [
     {
         T{ ##peek f 0 D 0 }
         T{ ##peek f 1 D 1 }
-        T{ ##sub f 2 1 1 }
-        T{ ##or f 3 0 2 }
+        T{ ##xor-imm f 3 0 0 }
         T{ ##replace f 3 D 0 }
     } value-numbering-step
 ] unit-test
@@ -1367,33 +1389,181 @@ cpu x86.32? [
 [
     {
         T{ ##peek f 0 D 0 }
-        T{ ##peek f 1 D 1 }
-        T{ ##load-integer f 2 0 }
-        T{ ##copy f 3 0 any-rep }
-        T{ ##replace f 3 D 0 }
+        T{ ##load-integer f 1 0 }
+        T{ ##replace f 1 D 0 }
     }
 ] [
     {
         T{ ##peek f 0 D 0 }
-        T{ ##peek f 1 D 1 }
-        T{ ##sub f 2 1 1 }
-        T{ ##xor f 3 0 2 }
-        T{ ##replace f 3 D 0 }
+        T{ ##and-imm f 1 0 0 }
+        T{ ##replace f 1 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##copy f 1 0 any-rep }
+        T{ ##replace f 1 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##and-imm f 1 0 -1 }
+        T{ ##replace f 1 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##copy f 1 0 any-rep }
+        T{ ##replace f 1 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##and f 1 0 0 }
+        T{ ##replace f 1 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##copy f 1 0 any-rep }
+        T{ ##replace f 1 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##or-imm f 1 0 0 }
+        T{ ##replace f 1 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##load-integer f 1 -1 }
+        T{ ##replace f 1 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##or-imm f 1 0 -1 }
+        T{ ##replace f 1 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##copy f 1 0 any-rep }
+        T{ ##replace f 1 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##or f 1 0 0 }
+        T{ ##replace f 1 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##copy f 1 0 any-rep }
+        T{ ##replace f 1 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##xor-imm f 1 0 0 }
+        T{ ##replace f 1 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##not f 1 0 }
+        T{ ##replace f 1 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##xor-imm f 1 0 -1 }
+        T{ ##replace f 1 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##load-integer f 1 0 }
+        T{ ##replace f 1 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##xor f 1 0 0 }
+        T{ ##replace f 1 D 0 }
     } value-numbering-step
 ] unit-test
 
 [
     {
         T{ ##peek f 0 D 0 }
-        T{ ##load-integer f 1 1 }
         T{ ##copy f 2 0 any-rep }
         T{ ##replace f 2 D 0 }
     }
 ] [
     {
         T{ ##peek f 0 D 0 }
-        T{ ##load-integer f 1 1 }
-        T{ ##mul f 2 0 1 }
+        T{ ##mul-imm f 2 0 1 }
+        T{ ##replace f 2 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##copy f 2 0 any-rep }
+        T{ ##replace f 2 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##shl-imm f 2 0 0 }
+        T{ ##replace f 2 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##copy f 2 0 any-rep }
+        T{ ##replace f 2 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##shr-imm f 2 0 0 }
+        T{ ##replace f 2 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##copy f 2 0 any-rep }
+        T{ ##replace f 2 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##sar-imm f 2 0 0 }
         T{ ##replace f 2 D 0 }
     } value-numbering-step
 ] unit-test
@@ -1644,7 +1814,55 @@ cell 8 = [
     } value-numbering-step
 ] unit-test
 
-! Displaced alien optimizations
+! Alien boxing and unboxing
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##box-alien f 1 0 }
+        T{ ##copy f 2 0 any-rep }
+        T{ ##replace f 2 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##box-alien f 1 0 }
+        T{ ##unbox-alien f 2 1 }
+        T{ ##replace f 2 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##box-alien f 1 0 }
+        T{ ##copy f 2 0 any-rep }
+        T{ ##replace f 2 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##box-alien f 1 0 }
+        T{ ##unbox-any-c-ptr f 2 1 }
+        T{ ##replace f 2 D 0 }
+    } value-numbering-step
+] unit-test
+
+[
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##load-integer f 2 0 }
+        T{ ##copy f 1 0 any-rep }
+        T{ ##replace f 1 D 0 }
+    }
+] [
+    {
+        T{ ##peek f 0 D 0 }
+        T{ ##load-integer f 2 0 }
+        T{ ##box-displaced-alien f 1 2 0 c-ptr }
+        T{ ##replace f 1 D 0 }
+    } value-numbering-step
+] unit-test
+
 3 vreg-counter set-global
 
 [
@@ -1701,6 +1919,7 @@ cell 8 = [
     } value-numbering-step
 ] unit-test
 
+! Various SIMD simplifications
 [
     {
         T{ ##vector>scalar f 1 0 float-4-rep }
diff --git a/basis/compiler/cfg/value-numbering/value-numbering.factor b/basis/compiler/cfg/value-numbering/value-numbering.factor
index 60ff4b2d00..dced1debb4 100644
--- a/basis/compiler/cfg/value-numbering/value-numbering.factor
+++ b/basis/compiler/cfg/value-numbering/value-numbering.factor
@@ -1,4 +1,4 @@
-! Copyright (C) 2008, 2009 Slava Pestov.
+! Copyright (C) 2008, 2010 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: namespaces assocs kernel accessors
 sorting sets sequences arrays
@@ -7,6 +7,7 @@ sequences.deep
 compiler.cfg
 compiler.cfg.rpo
 compiler.cfg.def-use
+compiler.cfg.utilities
 compiler.cfg.instructions
 compiler.cfg.value-numbering.alien
 compiler.cfg.value-numbering.comparisons
@@ -14,22 +15,28 @@ compiler.cfg.value-numbering.expressions
 compiler.cfg.value-numbering.graph
 compiler.cfg.value-numbering.math
 compiler.cfg.value-numbering.rewrite
-compiler.cfg.value-numbering.simplify
 compiler.cfg.value-numbering.slots ;
 IN: compiler.cfg.value-numbering
 
-! Local value numbering.
-
-: >copy ( insn -- insn/##copy )
-    dup dst>> dup vreg>vn vn>vreg
-    2dup eq? [ 2drop ] [ any-rep \ ##copy new-insn nip ] if ;
+: >copy ( insn vn dst -- insn/##copy )
+    swap vn>vreg 2dup eq? [ 2drop ] [ <copy> nip ] if ;
 
 GENERIC: process-instruction ( insn -- insn' )
 
 M: insn process-instruction
     dup rewrite
     [ process-instruction ]
-    [ dup defs-vreg [ dup number-values >copy ] when ] ?if ;
+    [
+        dup defs-vreg [
+            dup [ >expr expr>vn ] [ dst>> ] bi
+            [ set-vn drop ]
+            [ >copy ]
+            3bi
+        ] when
+    ] ?if ;
+
+M: ##copy process-instruction
+    dup [ src>> vreg>vn ] [ dst>> ] bi set-vn ;
 
 M: array process-instruction
     [ process-instruction ] map ;