diff --git a/basis/compiler/cfg/intrinsics/intrinsics.factor b/basis/compiler/cfg/intrinsics/intrinsics.factor
index 124aac5b18..bf65b50897 100644
--- a/basis/compiler/cfg/intrinsics/intrinsics.factor
+++ b/basis/compiler/cfg/intrinsics/intrinsics.factor
@@ -194,8 +194,8 @@ IN: compiler.cfg.intrinsics
         { math.vectors.simd.intrinsics:(simd-gather-2) [ emit-gather-vector-2 ] }
         { math.vectors.simd.intrinsics:(simd-gather-4) [ emit-gather-vector-4 ] }
         { math.vectors.simd.intrinsics:(simd-vshuffle) [ emit-shuffle-vector ] }
-        { math.vectors.simd.intrinsics:(simd-vmerge-head) [ [ ^^merge-vector-head ] emit-binary-vector-op ] }
-        { math.vectors.simd.intrinsics:(simd-vmerge-tail) [ [ ^^merge-vector-tail ] emit-binary-vector-op ] }
+        { math.vectors.simd.intrinsics:(simd-(vmerge-head)) [ [ ^^merge-vector-head ] emit-binary-vector-op ] }
+        { math.vectors.simd.intrinsics:(simd-(vmerge-tail)) [ [ ^^merge-vector-tail ] emit-binary-vector-op ] }
         { math.vectors.simd.intrinsics:(simd-select) [ emit-select-vector ] }
         { math.vectors.simd.intrinsics:(simd-sum) [ [ ^^horizontal-add-vector ] emit-unary-vector-op ] }
         { math.vectors.simd.intrinsics:alien-vector [ emit-alien-vector ] }
diff --git a/basis/compiler/cfg/linear-scan/linear-scan-tests.factor b/basis/compiler/cfg/linear-scan/linear-scan-tests.factor
index 2f49bf7fae..3a9a7ac0a1 100644
--- a/basis/compiler/cfg/linear-scan/linear-scan-tests.factor
+++ b/basis/compiler/cfg/linear-scan/linear-scan-tests.factor
@@ -1465,7 +1465,7 @@ V{
 
 [ ] [ { 1 2 3 } test-linear-scan-on-cfg ] unit-test
 
-[ { 1 } ] [ 1 get instructions>> first tagged-values>> ] unit-test
+[ { { 0 1 } } ] [ 1 get instructions>> first tagged-values>> ] unit-test
 
 V{
     T{ ##peek f 0 D 0 }
@@ -1487,4 +1487,4 @@ V{
 
 [ ] [ { 1 2 3 } test-linear-scan-on-cfg ] unit-test
 
-[ { 1 } ] [ 1 get instructions>> first tagged-values>> ] unit-test
+[ { { 0 1 } } ] [ 1 get instructions>> first tagged-values>> ] unit-test
diff --git a/basis/compiler/tree/propagation/simd/simd.factor b/basis/compiler/tree/propagation/simd/simd.factor
index 462e5d6e0b..ba319d5f85 100644
--- a/basis/compiler/tree/propagation/simd/simd.factor
+++ b/basis/compiler/tree/propagation/simd/simd.factor
@@ -31,8 +31,8 @@ IN: compiler.tree.propagation.simd
     (simd-hlshift)
     (simd-hrshift)
     (simd-vshuffle)
-    (simd-vmerge-head)
-    (simd-vmerge-tail)
+    (simd-(vmerge-head))
+    (simd-(vmerge-tail))
     (simd-v<=)
     (simd-v<)
     (simd-v=)
diff --git a/basis/math/vectors/simd/functor/functor.factor b/basis/math/vectors/simd/functor/functor.factor
index fb8326fde2..1c4c77133e 100644
--- a/basis/math/vectors/simd/functor/functor.factor
+++ b/basis/math/vectors/simd/functor/functor.factor
@@ -424,15 +424,15 @@ INSTANCE: A sequence
 : A-vmerge-head-op ( v1 v2 quot -- v )
     drop
     [ underlying1>> ] bi@
-    [ A-rep (simd-vmerge-head) ]
-    [ A-rep (simd-vmerge-tail) ] 2bi
+    [ A-rep (simd-(vmerge-head)) ]
+    [ A-rep (simd-(vmerge-tail)) ] 2bi
     \ A boa ;
     
 : A-vmerge-tail-op ( v1 v2 quot -- v )
     drop
     [ underlying2>> ] bi@
-    [ A-rep (simd-vmerge-head) ]
-    [ A-rep (simd-vmerge-tail) ] 2bi
+    [ A-rep (simd-(vmerge-head)) ]
+    [ A-rep (simd-(vmerge-tail)) ] 2bi
     \ A boa ;
 
 simd new
@@ -445,8 +445,8 @@ simd new
         { vnone? A-vany-op }
         { vany?  A-vany-op }
         { vall?  A-vall-op }
-        { vmerge-head A-vmerge-head-op }
-        { vmerge-tail A-vmerge-tail-op }
+        { (vmerge-head) A-vmerge-head-op }
+        { (vmerge-tail) A-vmerge-tail-op }
     } >>special-wrappers
     {
         { { +vector+ +vector+ -> +vector+ } A-vv->v-op }
diff --git a/basis/math/vectors/simd/intrinsics/intrinsics.factor b/basis/math/vectors/simd/intrinsics/intrinsics.factor
index dd87d4aaa9..0fd0d13f84 100644
--- a/basis/math/vectors/simd/intrinsics/intrinsics.factor
+++ b/basis/math/vectors/simd/intrinsics/intrinsics.factor
@@ -55,8 +55,8 @@ SIMD-OP: vrshift
 SIMD-OP: hlshift
 SIMD-OP: hrshift
 SIMD-OP: vshuffle
-SIMD-OP: vmerge-head
-SIMD-OP: vmerge-tail
+SIMD-OP: (vmerge-head)
+SIMD-OP: (vmerge-tail)
 SIMD-OP: v<=
 SIMD-OP: v<
 SIMD-OP: v=
@@ -120,46 +120,46 @@ GENERIC# supported-simd-op? 1 ( rep intrinsic -- ? )
 
 M: vector-rep supported-simd-op?
     {
-        { \ (simd-v+)           [ %add-vector-reps            ] }
-        { \ (simd-vs+)          [ %saturated-add-vector-reps  ] }
-        { \ (simd-v+-)          [ %add-sub-vector-reps        ] }
-        { \ (simd-v-)           [ %sub-vector-reps            ] }
-        { \ (simd-vs-)          [ %saturated-sub-vector-reps  ] }
-        { \ (simd-v*)           [ %mul-vector-reps            ] }
-        { \ (simd-vs*)          [ %saturated-mul-vector-reps  ] }
-        { \ (simd-v/)           [ %div-vector-reps            ] }
-        { \ (simd-vmin)         [ %min-vector-reps            ] }
-        { \ (simd-vmax)         [ %max-vector-reps            ] }
-        { \ (simd-v.)           [ %dot-vector-reps            ] }
-        { \ (simd-vsqrt)        [ %sqrt-vector-reps           ] }
-        { \ (simd-sum)          [ %horizontal-add-vector-reps ] }
-        { \ (simd-vabs)         [ %abs-vector-reps            ] }
-        { \ (simd-vbitand)      [ %and-vector-reps            ] }
-        { \ (simd-vbitandn)     [ %andn-vector-reps           ] }
-        { \ (simd-vbitor)       [ %or-vector-reps             ] }
-        { \ (simd-vbitxor)      [ %xor-vector-reps            ] }
-        { \ (simd-vbitnot)      [ %not-vector-reps            ] }
-        { \ (simd-vand)         [ %and-vector-reps            ] }
-        { \ (simd-vandn)        [ %andn-vector-reps           ] }
-        { \ (simd-vor)          [ %or-vector-reps             ] }
-        { \ (simd-vxor)         [ %xor-vector-reps            ] }
-        { \ (simd-vnot)         [ %not-vector-reps            ] }
-        { \ (simd-vlshift)      [ %shl-vector-reps            ] }
-        { \ (simd-vrshift)      [ %shr-vector-reps            ] }
-        { \ (simd-hlshift)      [ %horizontal-shl-vector-reps ] }
-        { \ (simd-hrshift)      [ %horizontal-shr-vector-reps ] }
-        { \ (simd-vshuffle)     [ %shuffle-vector-reps        ] }
-        { \ (simd-vmerge-head)  [ %merge-vector-reps          ] }
-        { \ (simd-vmerge-tail)  [ %merge-vector-reps          ] }
-        { \ (simd-v<=)          [ cc<= %compare-vector-reps   ] }
-        { \ (simd-v<)           [ cc< %compare-vector-reps    ] }
-        { \ (simd-v=)           [ cc= %compare-vector-reps    ] }
-        { \ (simd-v>)           [ cc> %compare-vector-reps    ] }
-        { \ (simd-v>=)          [ cc>= %compare-vector-reps   ] }
-        { \ (simd-vunordered?)  [ cc/<>= %compare-vector-reps ] }
-        { \ (simd-gather-2)     [ %gather-vector-2-reps       ] }
-        { \ (simd-gather-4)     [ %gather-vector-4-reps       ] }
-        { \ (simd-vany?)        [ %test-vector-reps           ] }
-        { \ (simd-vall?)        [ %test-vector-reps           ] }
-        { \ (simd-vnone?)       [ %test-vector-reps           ] }
+        { \ (simd-v+)            [ %add-vector-reps            ] }
+        { \ (simd-vs+)           [ %saturated-add-vector-reps  ] }
+        { \ (simd-v+-)           [ %add-sub-vector-reps        ] }
+        { \ (simd-v-)            [ %sub-vector-reps            ] }
+        { \ (simd-vs-)           [ %saturated-sub-vector-reps  ] }
+        { \ (simd-v*)            [ %mul-vector-reps            ] }
+        { \ (simd-vs*)           [ %saturated-mul-vector-reps  ] }
+        { \ (simd-v/)            [ %div-vector-reps            ] }
+        { \ (simd-vmin)          [ %min-vector-reps            ] }
+        { \ (simd-vmax)          [ %max-vector-reps            ] }
+        { \ (simd-v.)            [ %dot-vector-reps            ] }
+        { \ (simd-vsqrt)         [ %sqrt-vector-reps           ] }
+        { \ (simd-sum)           [ %horizontal-add-vector-reps ] }
+        { \ (simd-vabs)          [ %abs-vector-reps            ] }
+        { \ (simd-vbitand)       [ %and-vector-reps            ] }
+        { \ (simd-vbitandn)      [ %andn-vector-reps           ] }
+        { \ (simd-vbitor)        [ %or-vector-reps             ] }
+        { \ (simd-vbitxor)       [ %xor-vector-reps            ] }
+        { \ (simd-vbitnot)       [ %not-vector-reps            ] }
+        { \ (simd-vand)          [ %and-vector-reps            ] }
+        { \ (simd-vandn)         [ %andn-vector-reps           ] }
+        { \ (simd-vor)           [ %or-vector-reps             ] }
+        { \ (simd-vxor)          [ %xor-vector-reps            ] }
+        { \ (simd-vnot)          [ %not-vector-reps            ] }
+        { \ (simd-vlshift)       [ %shl-vector-reps            ] }
+        { \ (simd-vrshift)       [ %shr-vector-reps            ] }
+        { \ (simd-hlshift)       [ %horizontal-shl-vector-reps ] }
+        { \ (simd-hrshift)       [ %horizontal-shr-vector-reps ] }
+        { \ (simd-vshuffle)      [ %shuffle-vector-reps        ] }
+        { \ (simd-(vmerge-head)) [ %merge-vector-reps          ] }
+        { \ (simd-(vmerge-tail)) [ %merge-vector-reps          ] }
+        { \ (simd-v<=)           [ cc<= %compare-vector-reps   ] }
+        { \ (simd-v<)            [ cc< %compare-vector-reps    ] }
+        { \ (simd-v=)            [ cc= %compare-vector-reps    ] }
+        { \ (simd-v>)            [ cc> %compare-vector-reps    ] }
+        { \ (simd-v>=)           [ cc>= %compare-vector-reps   ] }
+        { \ (simd-vunordered?)   [ cc/<>= %compare-vector-reps ] }
+        { \ (simd-gather-2)      [ %gather-vector-2-reps       ] }
+        { \ (simd-gather-4)      [ %gather-vector-4-reps       ] }
+        { \ (simd-vany?)         [ %test-vector-reps           ] }
+        { \ (simd-vall?)         [ %test-vector-reps           ] }
+        { \ (simd-vnone?)        [ %test-vector-reps           ] }
     } case member? ;
diff --git a/basis/math/vectors/specialization/specialization.factor b/basis/math/vectors/specialization/specialization.factor
index 8d9d1b49cb..bed8a71f2c 100644
--- a/basis/math/vectors/specialization/specialization.factor
+++ b/basis/math/vectors/specialization/specialization.factor
@@ -98,8 +98,8 @@ H{
     { hrshift { +vector+ +literal+ -> +vector+ } }
     { vshuffle { +vector+ +literal+ -> +vector+ } }
     { vbroadcast { +vector+ +literal+ -> +vector+ } }
-    { vmerge-head { +vector+ +vector+ -> +vector+ } }
-    { vmerge-tail { +vector+ +vector+ -> +vector+ } }
+    { (vmerge-head) { +vector+ +vector+ -> +vector+ } }
+    { (vmerge-tail) { +vector+ +vector+ -> +vector+ } }
     { v<= { +vector+ +vector+ -> +vector+ } }
     { v< { +vector+ +vector+ -> +vector+ } }
     { v= { +vector+ +vector+ -> +vector+ } }
diff --git a/basis/math/vectors/vectors-docs.factor b/basis/math/vectors/vectors-docs.factor
index 82bb037186..7a9aff49b6 100644
--- a/basis/math/vectors/vectors-docs.factor
+++ b/basis/math/vectors/vectors-docs.factor
@@ -59,7 +59,8 @@ $nl
 { $subsection vbroadcast }
 { $subsection hlshift } 
 { $subsection hrshift }
-{ $subsection vmerge } ;
+{ $subsection vmerge }
+{ $subsection (vmerge) } ;
 
 ARTICLE: "math-vectors-logic" "Vector component- and bit-wise logic"
 { $notes
@@ -357,37 +358,50 @@ HELP: hrshift
 { $description "Shifts the entire SIMD array to the right by " { $snippet "n" } " bytes, filling the vacated left-hand bits with zeroes. This word may only be used in a context where the compiler can statically infer that the input is a SIMD array." } ;
 
 HELP: vmerge
-{ $values { "u" "a sequence" } { "v" "a sequence" } { "h" "a sequence" } { "t" "a sequence" } }
-{ $description "Creates two new sequences of the same type and size as " { $snippet "u" } " and " { $snippet "v" } " by interleaving the elements of " { $snippet "u" } " and " { $snippet "v" } "." }
+{ $values { "u" "a sequence" } { "v" "a sequence" } { "w" "a sequence" } }
+{ $description "Creates a new sequence of the same type as and twice the length of " { $snippet "u" } " and " { $snippet "v" } " by interleaving the elements of " { $snippet "u" } " and " { $snippet "v" } "." }
 { $examples
 { $example """USING: kernel math.vectors prettyprint ;
 
-{ "A" "B" "C" "D" } { "1" "2" "3" "4" } vmerge [ . ] bi@"""
+{ "A" "B" "C" "D" } { "1" "2" "3" "4" } vmerge ."""
+"""{ "A" "1" "B" "2" "C" "3" "D" "4" }"""
+} } ;
+
+HELP: (vmerge)
+{ $values { "u" "a sequence" } { "v" "a sequence" } { "h" "a sequence" } { "t" "a sequence" } }
+{ $description "Creates two new sequences of the same type and size as " { $snippet "u" } " and " { $snippet "v" } " by interleaving the elements of " { $snippet "u" } " and " { $snippet "v" } "." }
+{ $notes "For hardware-supported SIMD vector types this word compiles to a single instruction per output value." }
+{ $examples
+{ $example """USING: kernel math.vectors prettyprint ;
+
+{ "A" "B" "C" "D" } { "1" "2" "3" "4" } (vmerge) [ . ] bi@"""
 """{ "A" "1" "B" "2" }
 { "C" "3" "D" "4" }"""
 } } ;
 
-HELP: vmerge-head
+HELP: (vmerge-head)
 { $values { "u" "a sequence" } { "v" "a sequence" } { "h" "a sequence" } }
-{ $description "Creates two new sequences of the same type and size as " { $snippet "u" } " and " { $snippet "v" } " by interleaving the elements from the first half of " { $snippet "u" } " and " { $snippet "v" } "." }
+{ $description "Creates a new sequence of the same type and size as " { $snippet "u" } " and " { $snippet "v" } " by interleaving the elements from the first half of " { $snippet "u" } " and " { $snippet "v" } "." }
+{ $notes "For hardware-supported SIMD vector types this word compiles to a single instruction." }
 { $examples
 { $example """USING: kernel math.vectors prettyprint ;
 
-{ "A" "B" "C" "D" } { "1" "2" "3" "4" } vmerge-head ."""
+{ "A" "B" "C" "D" } { "1" "2" "3" "4" } (vmerge-head) ."""
 """{ "A" "1" "B" "2" }"""
 } } ;
 
-HELP: vmerge-tail
+HELP: (vmerge-tail)
 { $values { "u" "a sequence" } { "v" "a sequence" } { "t" "a sequence" } }
-{ $description "Creates two new sequences of the same type and size as " { $snippet "u" } " and " { $snippet "v" } " by interleaving the elements from the tail half of " { $snippet "u" } " and " { $snippet "v" } "." }
+{ $description "Creates a new sequence of the same type and size as " { $snippet "u" } " and " { $snippet "v" } " by interleaving the elements from the tail half of " { $snippet "u" } " and " { $snippet "v" } "." }
+{ $notes "For hardware-supported SIMD vector types this word compiles to a single instruction." }
 { $examples
 { $example """USING: kernel math.vectors prettyprint ;
 
-{ "A" "B" "C" "D" } { "1" "2" "3" "4" } vmerge-tail ."""
+{ "A" "B" "C" "D" } { "1" "2" "3" "4" } (vmerge-tail) ."""
 """{ "C" "3" "D" "4" }"""
 } } ;
 
-{ vmerge vmerge-head vmerge-tail } related-words
+{ vmerge (vmerge) (vmerge-head) (vmerge-tail) } related-words
 
 HELP: vbroadcast
 { $values { "u" "a SIMD array" } { "n" "a non-negative integer" } { "v" "a SIMD array" } }
diff --git a/basis/math/vectors/vectors.factor b/basis/math/vectors/vectors.factor
index 3f4fe4c7b6..c65009950d 100644
--- a/basis/math/vectors/vectors.factor
+++ b/basis/math/vectors/vectors.factor
@@ -91,10 +91,15 @@ PRIVATE>
 : hlshift ( u n -- w ) '[ _ <byte-array> prepend 16 head ] change-underlying ;
 : hrshift ( u n -- w ) '[ _ <byte-array> append 16 tail* ] change-underlying ;
 
-: vmerge-head ( u v -- h ) over length 2 / '[ _ head-slice ] bi@ [ zip ] keep concat-as ;
-: vmerge-tail ( u v -- t ) over length 2 / '[ _ tail-slice ] bi@ [ zip ] keep concat-as ;
+: (vmerge-head) ( u v -- h )
+    over length 2 /i '[ _ head-slice ] bi@ [ zip ] keep concat-as ;
+: (vmerge-tail) ( u v -- t )
+    over length 2 /i '[ _ tail-slice ] bi@ [ zip ] keep concat-as ;
 
-: vmerge ( u v -- h t ) [ vmerge-head ] [ vmerge-tail ] 2bi ; inline
+: (vmerge) ( u v -- h t )
+    [ (vmerge-head) ] [ (vmerge-tail) ] 2bi ; inline
+
+: vmerge ( u v -- w ) [ zip ] keep concat-as ;
 
 : vand ( u v -- w )  over '[ [ _ element>bool ] bi@ and ] 2map ;
 : vandn ( u v -- w ) over '[ [ _ element>bool ] bi@ [ not ] dip and ] 2map ;
diff --git a/extra/math/matrices/simd/simd.factor b/extra/math/matrices/simd/simd.factor
index 1fdb4f6d56..da1149dfec 100644
--- a/extra/math/matrices/simd/simd.factor
+++ b/extra/math/matrices/simd/simd.factor
@@ -120,7 +120,7 @@ TYPED:: m4^n ( m: matrix4 n: fixnum -- m^n: matrix4 )
     identity-matrix4 n [ m m4. ] times ;
 
 : vmerge-diagonal* ( x y -- h t )
-    [ vmerge-head ] [ swap vmerge-tail ] 2bi ; inline
+    [ (vmerge-head) ] [ swap (vmerge-tail) ] 2bi ; inline
 : vmerge-diagonal ( x -- h t )
     0.0 float-4-with vmerge-diagonal* ; inline
 
@@ -128,7 +128,7 @@ TYPED: diagonal-matrix4 ( diagonal: float-4 -- matrix: matrix4 )
     [ vmerge-diagonal [ vmerge-diagonal ] bi@ ] make-matrix4 ;
 
 : vmerge-transpose ( a b c d -- a' b' c' d' )
-    [ vmerge ] bi-curry@ bi* ; inline
+    [ (vmerge) ] bi-curry@ bi* ; inline
 
 TYPED: transpose-matrix4 ( matrix: matrix4 -- matrix: matrix4 )
     [ rows vmerge-transpose vmerge-transpose ] make-matrix4 ;
@@ -144,8 +144,8 @@ TYPED:: translation-matrix4 ( offset: float-4 -- matrix: matrix4 )
     [
         float-4{ 1.0 1.0 1.0 1.0 } :> diagonal
 
-        offset 0 float-4-with vmerge
-        [ 0 float-4-with swap vmerge ] bi@ drop :> z :> y :> x
+        offset 0 float-4-with (vmerge)
+        [ 0 float-4-with swap (vmerge) ] bi@ drop :> z :> y :> x
 
         diagonal y vmerge-diagonal*
         [ x vmerge-diagonal* ]
@@ -194,7 +194,7 @@ TYPED:: frustum-matrix4 ( xy: float-4 near: float far: float -- matrix: matrix4
         float-4{ t t f f } xy near far - float-4-with v? ! denom
         v/ :> fov
         
-        fov 0.0 float-4-with vmerge-head vmerge-diagonal
+        fov 0.0 float-4-with (vmerge-head) vmerge-diagonal
         fov float-4{ f f t t } vand
         float-4{ 0.0 0.0 -1.0 0.0 }
     ] make-matrix4 ;
diff --git a/vm/os-genunix.cpp b/vm/os-genunix.cpp
index 7bbe388ff2..065f0dfd40 100644
--- a/vm/os-genunix.cpp
+++ b/vm/os-genunix.cpp
@@ -30,6 +30,7 @@ const char *default_image_path()
 	char *new_path = new char[PATH_MAX + SUFFIX_LEN + 1];
 	memcpy(new_path,path,len + 1);
 	memcpy(new_path + len,SUFFIX,SUFFIX_LEN + 1);
+	free(const_cast<char *>(path));
 	return new_path;
 }
 
diff --git a/vm/os-linux.cpp b/vm/os-linux.cpp
index 2d26fba390..352467d379 100644
--- a/vm/os-linux.cpp
+++ b/vm/os-linux.cpp
@@ -3,7 +3,7 @@
 namespace factor
 {
 
-/* Snarfed from SBCL linux-so.c. You must delete[] the result yourself. */
+/* Snarfed from SBCL linux-so.c. You must free() the result yourself. */
 const char *vm_executable_path()
 {
 	char *path = new char[PATH_MAX + 1];
@@ -17,7 +17,10 @@ const char *vm_executable_path()
 	else
 	{
 		path[size] = '\0';
-		return safe_strdup(path);
+
+		const char *ret = safe_strdup(path);
+		delete[] path;
+		return ret;
 	}
 }