diff --git a/basis/compiler/cfg/linear-scan/live-intervals/live-intervals.factor b/basis/compiler/cfg/linear-scan/live-intervals/live-intervals.factor
index be151b2002..5ac733114b 100644
--- a/basis/compiler/cfg/linear-scan/live-intervals/live-intervals.factor
+++ b/basis/compiler/cfg/linear-scan/live-intervals/live-intervals.factor
@@ -31,8 +31,11 @@ M: live-interval clone
 SYMBOL: live-intervals
 
 : new-live-interval ( n vreg live-intervals -- )
-    2dup key? [ "Multiple defs" throw ] when
-    [ [ <live-interval> ] keep ] dip set-at ;
+    2dup key? [
+        at add-use
+    ] [
+        [ [ <live-interval> ] keep ] dip set-at
+    ] if ;
 
 : compute-live-intervals* ( insn n -- )
     live-intervals get
diff --git a/basis/compiler/cfg/two-operand/two-operand.factor b/basis/compiler/cfg/two-operand/two-operand.factor
new file mode 100644
index 0000000000..e943fb4828
--- /dev/null
+++ b/basis/compiler/cfg/two-operand/two-operand.factor
@@ -0,0 +1,60 @@
+! Copyright (C) 2008 Slava Pestov.
+! See http://factorcode.org/license.txt for BSD license.
+USING: accessors arrays kernel sequences sequences.deep
+compiler.cfg.instructions cpu.architecture ;
+IN: compiler.cfg.two-operand
+
+! On x86, instructions take the form x = x op y
+! Our SSA IR is x = y op z
+
+! We don't bother with ##add, ##add-imm or ##sub-imm since x86
+! has a LEA instruction which is effectively a three-operand
+! addition
+
+: make-copy ( dst src -- insn ) f \ ##copy boa ; inline
+
+: make-copy/float ( dst src -- insn ) f \ ##copy-float boa ; inline
+
+: convert-two-operand/integer ( insn -- insns )
+    [ [ dst>> ] [ src1>> ] bi make-copy ]
+    [ dup dst>> >>src1 ]
+    bi 2array ; inline
+
+: convert-two-operand/float ( insn -- insns )
+    [ [ dst>> ] [ src1>> ] bi make-copy/float ]
+    [ dup dst>> >>src1 ]
+    bi 2array ; inline
+
+GENERIC: convert-two-operand* ( insn -- insns )
+
+M: ##not convert-two-operand*
+    [ [ dst>> ] [ src>> ] bi make-copy ]
+    [ dup dst>> >>src ]
+    bi 2array ;
+
+M: ##sub convert-two-operand* convert-two-operand/integer ;
+M: ##mul convert-two-operand* convert-two-operand/integer ;
+M: ##mul-imm convert-two-operand* convert-two-operand/integer ;
+M: ##and convert-two-operand* convert-two-operand/integer ;
+M: ##and-imm convert-two-operand* convert-two-operand/integer ;
+M: ##or convert-two-operand* convert-two-operand/integer ;
+M: ##or-imm convert-two-operand* convert-two-operand/integer ;
+M: ##xor convert-two-operand* convert-two-operand/integer ;
+M: ##xor-imm convert-two-operand* convert-two-operand/integer ;
+M: ##shl-imm convert-two-operand* convert-two-operand/integer ;
+M: ##shr-imm convert-two-operand* convert-two-operand/integer ;
+M: ##sar-imm convert-two-operand* convert-two-operand/integer ;
+
+M: ##add-float convert-two-operand* convert-two-operand/float ;
+M: ##sub-float convert-two-operand* convert-two-operand/float ;
+M: ##mul-float convert-two-operand* convert-two-operand/float ;
+M: ##div-float convert-two-operand* convert-two-operand/float ;
+
+M: insn convert-two-operand* ;
+
+: convert-two-operand ( mr -- mr' )
+    [
+        two-operand? [
+            [ convert-two-operand* ] map flatten
+        ] when
+    ] change-instructions ;
diff --git a/basis/compiler/compiler.factor b/basis/compiler/compiler.factor
index f3767ec688..0a21749d84 100644
--- a/basis/compiler/compiler.factor
+++ b/basis/compiler/compiler.factor
@@ -7,8 +7,8 @@ stack-checker stack-checker.state stack-checker.inlining
 compiler.errors compiler.units compiler.tree.builder
 compiler.tree.optimizer compiler.cfg.builder
 compiler.cfg.optimizer compiler.cfg.linearization
-compiler.cfg.linear-scan compiler.cfg.stack-frame
-compiler.codegen ;
+compiler.cfg.two-operand compiler.cfg.linear-scan
+compiler.cfg.stack-frame compiler.codegen ;
 IN: compiler
 
 SYMBOL: compile-queue
@@ -76,6 +76,7 @@ t compile-dependencies? set-global
     build-cfg [
         optimize-cfg
         build-mr
+        convert-two-operand
         linear-scan
         build-stack-frame
         generate
diff --git a/basis/cpu/architecture/architecture.factor b/basis/cpu/architecture/architecture.factor
index e90f58fd49..f7cce8e70a 100644
--- a/basis/cpu/architecture/architecture.factor
+++ b/basis/cpu/architecture/architecture.factor
@@ -35,6 +35,8 @@ GENERIC: param-reg ( n register-class -- reg )
 
 M: object param-reg param-regs nth ;
 
+HOOK: two-operand? cpu ( -- ? )
+
 HOOK: %load-immediate cpu ( reg obj -- )
 HOOK: %load-indirect cpu ( reg obj -- )
 
diff --git a/basis/cpu/x86/architecture/architecture.factor b/basis/cpu/x86/architecture/architecture.factor
index 65067740d9..615550587c 100644
--- a/basis/cpu/x86/architecture/architecture.factor
+++ b/basis/cpu/x86/architecture/architecture.factor
@@ -9,6 +9,8 @@ compiler.cfg.instructions compiler.codegen
 compiler.codegen.fixup ;
 IN: cpu.x86.architecture
 
+M: x86 two-operand? t ;
+
 HOOK: temp-reg-1 cpu ( -- reg )
 HOOK: temp-reg-2 cpu ( -- reg )
 
@@ -83,31 +85,22 @@ M: x86 %slot-imm ( dst obj slot tag -- ) (%slot-imm) MOV ;
 M: x86 %set-slot ( src obj slot tag temp -- ) (%slot) swap MOV ;
 M: x86 %set-slot-imm ( src obj slot tag -- ) (%slot-imm) swap MOV ;
 
-: ?MOV ( dst src -- )
-    2dup = [ 2drop ] [ MOV ] if ; inline
-
-: 1operand ( dst src -- dst' )
-    dupd ?MOV ; inline
-
-: 2operand ( dst src1 src2 -- dst src )
-    [ 1operand ] dip ; inline
-
 M: x86 %add     [+] LEA ;
 M: x86 %add-imm [+] LEA ;
-M: x86 %sub     2operand SUB ;
+M: x86 %sub     nip SUB ;
 M: x86 %sub-imm neg [+] LEA ;
-M: x86 %mul     2operand swap IMUL2 ;
-M: x86 %mul-imm 2operand IMUL2 ;
-M: x86 %and     2operand AND ;
-M: x86 %and-imm 2operand AND ;
-M: x86 %or      2operand OR ;
-M: x86 %or-imm  2operand OR ;
-M: x86 %xor     2operand XOR ;
-M: x86 %xor-imm 2operand XOR ;
-M: x86 %shl-imm 2operand SHL ;
-M: x86 %shr-imm 2operand SHR ;
-M: x86 %sar-imm 2operand SAR ;
-M: x86 %not     1operand NOT ;
+M: x86 %mul     nip swap IMUL2 ;
+M: x86 %mul-imm nip IMUL2 ;
+M: x86 %and     nip AND ;
+M: x86 %and-imm nip AND ;
+M: x86 %or      nip OR ;
+M: x86 %or-imm  nip OR ;
+M: x86 %xor     nip XOR ;
+M: x86 %xor-imm nip XOR ;
+M: x86 %shl-imm nip SHL ;
+M: x86 %shr-imm nip SHR ;
+M: x86 %sar-imm nip SAR ;
+M: x86 %not     drop NOT ;
 
 : bignum@ ( reg n -- op )
     cells bignum tag-number - [+] ; inline
@@ -164,26 +157,21 @@ M:: x86 %bignum>integer ( dst src -- )
         "end" resolve-label
     ] with-scope ;
 
-: ?MOVSD ( dst src -- )
-    2dup = [ 2drop ] [ MOVSD ] if ; inline
-
-: 1operand-fp ( dst src -- dst' )
-    dupd ?MOVSD ; inline
-
-: 2operand-fp ( dst src1 src2 -- dst src )
-    [ 1operand-fp ] dip ; inline
-
-M: x86 %add-float 2operand-fp ADDSD ;
-M: x86 %sub-float 2operand-fp SUBSD ;
-M: x86 %mul-float 2operand-fp MULSD ;
-M: x86 %div-float 2operand-fp DIVSD ;
+M: x86 %add-float nip ADDSD ;
+M: x86 %sub-float nip SUBSD ;
+M: x86 %mul-float nip MULSD ;
+M: x86 %div-float nip DIVSD ;
 
 M: x86 %integer>float CVTSI2SD ;
 M: x86 %float>integer CVTTSD2SI ;
 
-M: x86 %copy ( dst src -- ) MOV ;
+: ?MOV ( dst src -- )
+    2dup = [ 2drop ] [ MOV ] if ; inline
 
-M: x86 %copy-float MOVSD ;
+M: x86 %copy ( dst src -- ) ?MOV ;
+
+M: x86 %copy-float ( dst src -- )
+    2dup = [ 2drop ] [ MOVSD ] if ;
 
 M: x86 %unbox-float ( dst src -- )
     float-offset [+] MOVSD ;