diff --git a/src/crypto_scalarmult/curve25519/amd64/mulx/curve25519.jinc b/src/crypto_scalarmult/curve25519/amd64/mulx/curve25519.jinc
index 280c44f6..7f2d397b 100644
--- a/src/crypto_scalarmult/curve25519/amd64/mulx/curve25519.jinc
+++ b/src/crypto_scalarmult/curve25519/amd64/mulx/curve25519.jinc
@@ -97,8 +97,8 @@ inline fn __montgomery_ladder4(
 {
   stack u64[4] us x2 x3 z3;
   reg u64[4] z2r;
-  stack u64 ctrs swapped;
-  reg u64 ctr;
+  stack u64 swapped;
+  #spill_to_mmx reg u64 ctr;
 
   (x2,z2r,x3,z3) = __init_points4(u); 
   us = #copy(u);
@@ -109,12 +109,12 @@ inline fn __montgomery_ladder4(
   while
   {
     ctr -= 1;
-    ctrs = ctr;
+    () = #spill(ctr);
 
     (x2, z2r, x3, z3, swapped) = 
       __montgomery_ladder_step4(k, us, x2, z2r, x3, z3, swapped, ctr);
 
-    ctr = ctrs;
+    () = #unspill(ctr);
   } (ctr > 0)
 
   return x2, z2r;
diff --git a/src/crypto_scalarmult/curve25519/amd64/mulx/scalarmult.jazz b/src/crypto_scalarmult/curve25519/amd64/mulx/scalarmult.jazz
index d6146eca..26ca4ffb 100644
--- a/src/crypto_scalarmult/curve25519/amd64/mulx/scalarmult.jazz
+++ b/src/crypto_scalarmult/curve25519/amd64/mulx/scalarmult.jazz
@@ -1,37 +1,39 @@
 from Jade require "crypto_scalarmult/curve25519/amd64/common/load_store4.jinc"
 require "curve25519.jinc"
 
-export fn jade_scalarmult_curve25519_amd64_mulx(reg u64 qp np pp) -> reg u64
+export fn jade_scalarmult_curve25519_amd64_mulx(#spill_to_mmx reg u64 qp np pp) -> reg u64
 {
   reg u64 r;
-  stack u64 qps;
   reg u64[4] q n p;
 
-  qps = qp;
+  _ = #init_msf();
+
+  ()  = #spill(qp);
   n   = __load4(np);
   p   = __load4(pp);
 
   q = __curve25519_mulx(n, p);
 
-  qp = qps;
+  ()  = #unspill(qp);
   __store4(qp, q);
 
   ?{}, r = #set0();
   return r;
 }
 
-export fn jade_scalarmult_curve25519_amd64_mulx_base(reg u64 qp np) -> reg u64
+export fn jade_scalarmult_curve25519_amd64_mulx_base(#spill_to_mmx reg u64 qp np) -> reg u64
 {
   reg u64 r;
-  stack u64 qps;
   reg u64[4] q n;
 
-  qps = qp;
+  _ = #init_msf();
+
+  ()  = #spill(qp);
   n   = __load4(np);
 
   q = __curve25519_mulx_base(n);
 
-  qp = qps;
+  ()  = #unspill(qp);
   __store4(qp, q);
 
   ?{}, r = #set0();
diff --git a/src/crypto_scalarmult/curve25519/amd64/ref4/curve25519.jinc b/src/crypto_scalarmult/curve25519/amd64/ref4/curve25519.jinc
index 47c40757..38ddbb8a 100644
--- a/src/crypto_scalarmult/curve25519/amd64/ref4/curve25519.jinc
+++ b/src/crypto_scalarmult/curve25519/amd64/ref4/curve25519.jinc
@@ -96,8 +96,8 @@ inline fn __montgomery_ladder4(
 {
   stack u64[4] us x2 x3 z3;
   reg u64[4] z2r;
-  stack u64 ctrs swapped;
-  reg u64 ctr;
+  stack u64 swapped;
+  #spill_to_mmx reg u64 ctr;
 
   (x2,z2r,x3,z3) = __init_points4(u); 
   us = #copy(u);
@@ -108,12 +108,12 @@ inline fn __montgomery_ladder4(
   while
   {
     ctr -= 1;
-    ctrs = ctr;
+    () = #spill(ctr);
 
     (x2, z2r, x3, z3, swapped) = 
       __montgomery_ladder_step4(k, us, x2, z2r, x3, z3, swapped, ctr);
 
-    ctr = ctrs;
+    () = #unspill(ctr);
   } (ctr > 0)
 
   return x2, z2r;
diff --git a/src/crypto_scalarmult/curve25519/amd64/ref4/scalarmult.jazz b/src/crypto_scalarmult/curve25519/amd64/ref4/scalarmult.jazz
index 7750b8c6..70e3a1f9 100644
--- a/src/crypto_scalarmult/curve25519/amd64/ref4/scalarmult.jazz
+++ b/src/crypto_scalarmult/curve25519/amd64/ref4/scalarmult.jazz
@@ -1,37 +1,39 @@
 from Jade require "crypto_scalarmult/curve25519/amd64/common/load_store4.jinc"
 require "curve25519.jinc"
 
-export fn jade_scalarmult_curve25519_amd64_ref4(reg u64 qp np pp) -> reg u64
+export fn jade_scalarmult_curve25519_amd64_ref4(#spill_to_mmx reg u64 qp np pp) -> reg u64
 {
   reg u64 r;
-  stack u64 qps;
   reg u64[4] q n p;
 
-  qps = qp;
+  _ = #init_msf();
+
+  ()  = #spill(qp);
   n   = __load4(np);
   p   = __load4(pp);
 
   q = __curve25519_ref4(n, p);
 
-  qp = qps;
+  ()  = #unspill(qp);
   __store4(qp, q);
 
   ?{}, r = #set0();
   return r;
 }
 
-export fn jade_scalarmult_curve25519_amd64_ref4_base(reg u64 qp np) -> reg u64
+export fn jade_scalarmult_curve25519_amd64_ref4_base(#spill_to_mmx reg u64 qp np) -> reg u64
 {
   reg u64 r;
-  stack u64 qps;
   reg u64[4] q n;
 
-  qps = qp;
+  _ = #init_msf();
+
+  ()  = #spill(qp);
   n   = __load4(np);
 
   q = __curve25519_ref4_base(n);
 
-  qp = qps;
+  ()  = #unspill(qp);
   __store4(qp, q);
 
   ?{}, r = #set0();
diff --git a/src/crypto_scalarmult/curve25519/amd64/ref5/curve25519.jinc b/src/crypto_scalarmult/curve25519/amd64/ref5/curve25519.jinc
index 6963fcde..2a289f2d 100644
--- a/src/crypto_scalarmult/curve25519/amd64/ref5/curve25519.jinc
+++ b/src/crypto_scalarmult/curve25519/amd64/ref5/curve25519.jinc
@@ -94,8 +94,8 @@ inline fn __montgomery_ladder5(
 {
   stack u64[5] us x2 x3 z3;
   reg u64[5] z2r;
-  stack u64 ctrs swapped;
-  reg u64 ctr;
+  stack u64 swapped;
+  #spill_to_mmx reg u64 ctr;
 
   (x2,z2r,x3,z3) = __init_points5(u); 
   us = #copy(u);
@@ -106,12 +106,12 @@ inline fn __montgomery_ladder5(
   while
   {
     ctr -= 1;
-    ctrs = ctr;
+    () = #spill(ctr);
 
     (x2, z2r, x3, z3, swapped) = 
       __montgomery_ladder_step5(k, us, x2, z2r, x3, z3, swapped, ctr);
 
-    ctr = ctrs;
+    () = #unspill(ctr);
   } (ctr > 0)
 
   return x2, z2r;
diff --git a/src/crypto_scalarmult/curve25519/amd64/ref5/scalarmult.jazz b/src/crypto_scalarmult/curve25519/amd64/ref5/scalarmult.jazz
index 88556ba3..50d2d533 100644
--- a/src/crypto_scalarmult/curve25519/amd64/ref5/scalarmult.jazz
+++ b/src/crypto_scalarmult/curve25519/amd64/ref5/scalarmult.jazz
@@ -1,37 +1,41 @@
 from Jade require "crypto_scalarmult/curve25519/amd64/common/load_store4.jinc"
 require "curve25519.jinc"
 
-export fn jade_scalarmult_curve25519_amd64_ref5(reg u64 qp np pp) -> reg u64
+export fn jade_scalarmult_curve25519_amd64_ref5(#spill_to_mmx reg u64 qp np pp) -> reg u64
 {
   reg u64 r;
   stack u64 qps;
   reg u64[4] q n p;
 
-  qps = qp;
+  _ = #init_msf();
+
+  ()  = #spill(qp);
   n   = __load4(np);
   p   = __load4(pp);
 
   q = __curve25519_ref5(n, p);
 
-  qp = qps;
+  ()  = #unspill(qp);
   __store4(qp, q);
 
   ?{}, r = #set0();
   return r;
 }
 
-export fn jade_scalarmult_curve25519_amd64_ref5_base(reg u64 qp np) -> reg u64
+export fn jade_scalarmult_curve25519_amd64_ref5_base(#spill_to_mmx reg u64 qp np) -> reg u64
 {
   reg u64 r;
   stack u64 qps;
   reg u64[4] q n;
 
-  qps = qp;
+  _ = #init_msf();
+
+  ()  = #spill(qp);
   n   = __load4(np);
 
   q = __curve25519_ref5_base(n);
 
-  qp = qps;
+  ()  = #unspill(qp);
   __store4(qp, q);
 
   ?{}, r = #set0();