Enable x25519 SSE2 for MS compilers (GH #761)

1 files changed, 8 insertions, 8 deletions

diff --git a/donna_sse.cpp b/donna_sse.cpp
index 2f6a68ac..3ab13076 100644
--- a/donna_sse.cpp
+++ b/donna_sse.cpp
@@ -214,7 +214,7 @@ curve25519_contract(byte out[32], const bignum25519 in) {
  */

 inline void

 curve25519_swap_conditional(bignum25519 a, bignum25519 b, word32 iswap) {

-    const word32 swap = (word32)(-(int32_t)iswap);

+    const word32 swap = (word32)(-(sword32)iswap);

     xmmi a0,a1,a2,b0,b1,b2,x0,x1,x2;

     xmmi mask = _mm_cvtsi32_si128(swap);

     mask = _mm_shuffle_epi32(mask, 0);

@@ -1114,16 +1114,16 @@ int curve25519_SSE2(byte sharedKey[32], const byte secretKey[32], const byte oth
     packed32bignum25519 qx, qz, pqz, pqx;

     packed64bignum25519 nq, sq, sqscalar, prime, primex, primez, nqpq;

     bignum25519mulprecomp preq;

-    size_t bit, lastbit;

+    size_t i=0, bit=0, lastbit=0;

 

     curve25519_expand(nqpqx, othersKey);

     curve25519_mul_precompute(&preq, nqpqx);

 

     /* do bits 254..3 */

-    for (int i = 254, lastbit = 0; i >= 3; i--) {

+    for (i = 254, lastbit=0; i >= 3; i--) {

         bit = (e[i/8] >> (i & 7)) & 1;

-        curve25519_swap_conditional(nqx, nqpqx, bit ^ lastbit);

-        curve25519_swap_conditional(nqz, nqpqz, bit ^ lastbit);

+        curve25519_swap_conditional(nqx, nqpqx, (word32)(bit ^ lastbit));

+        curve25519_swap_conditional(nqz, nqpqz, (word32)(bit ^ lastbit));

         lastbit = bit;

 

         curve25519_tangle32(qx, nqx, nqpqx); /* qx = [nqx,nqpqx] */

@@ -1149,11 +1149,11 @@ int curve25519_SSE2(byte sharedKey[32], const byte secretKey[32], const byte oth
 

     /* it's possible to get rid of this swap with the swap in the above loop

        at the bottom instead of the top, but compilers seem to optimize better this way */

-    curve25519_swap_conditional(nqx, nqpqx, bit);

-    curve25519_swap_conditional(nqz, nqpqz, bit);

+    curve25519_swap_conditional(nqx, nqpqx, (word32)bit);

+    curve25519_swap_conditional(nqz, nqpqz, (word32)bit);

 

     /* do bits 2..0 */

-    for (size_t i = 0; i < 3; i++) {

+    for (i = 0; i < 3; i++) {

         curve25519_compute_nq(nq, nqx, nqz);

         curve25519_square_packed64(sq, nq); /* sq = nq^2 */

         curve25519_121665_packed64(sqscalar, sq); /* sqscalar = sq * [121666,121665] */