1 files changed, 58 insertions, 0 deletions
diff --git a/sys/contrib/libsodium/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_invert.c b/sys/contrib/libsodium/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_invert.c
new file mode 100644
index 000000000000..ec9bb1a91f66
--- /dev/null
+++ b/sys/contrib/libsodium/src/libsodium/crypto_scalarmult/curve25519/sandy2x/fe51_invert.c
@@ -0,0 +1,58 @@
+/*
+   This file is adapted from amd64-51/fe25519_invert.c:
+   Loops of squares are replaced by nsquares for better performance.
+*/
+
+#include "fe51.h"
+
+#ifdef HAVE_AVX_ASM
+
+#define fe51_square(x, y) fe51_nsquare(x, y, 1)
+
+void
+fe51_invert(fe51 *r, const fe51 *x)
+{
+    fe51 z2;
+    fe51 z9;
+    fe51 z11;
+    fe51 z2_5_0;
+    fe51 z2_10_0;
+    fe51 z2_20_0;
+    fe51 z2_50_0;
+    fe51 z2_100_0;
+    fe51 t;
+
+    /* 2 */ fe51_square(&z2,x);
+    /* 4 */ fe51_square(&t,&z2);
+    /* 8 */ fe51_square(&t,&t);
+    /* 9 */ fe51_mul(&z9,&t,x);
+    /* 11 */ fe51_mul(&z11,&z9,&z2);
+    /* 22 */ fe51_square(&t,&z11);
+    /* 2^5 - 2^0 = 31 */ fe51_mul(&z2_5_0,&t,&z9);
+
+    /* 2^10 - 2^5 */ fe51_nsquare(&t,&z2_5_0, 5);
+    /* 2^10 - 2^0 */ fe51_mul(&z2_10_0,&t,&z2_5_0);
+
+    /* 2^20 - 2^10 */ fe51_nsquare(&t,&z2_10_0, 10);
+    /* 2^20 - 2^0 */ fe51_mul(&z2_20_0,&t,&z2_10_0);
+
+    /* 2^40 - 2^20 */ fe51_nsquare(&t,&z2_20_0, 20);
+    /* 2^40 - 2^0 */ fe51_mul(&t,&t,&z2_20_0);
+
+    /* 2^50 - 2^10 */ fe51_nsquare(&t,&t,10);
+    /* 2^50 - 2^0 */ fe51_mul(&z2_50_0,&t,&z2_10_0);
+
+    /* 2^100 - 2^50 */ fe51_nsquare(&t,&z2_50_0, 50);
+    /* 2^100 - 2^0 */ fe51_mul(&z2_100_0,&t,&z2_50_0);
+
+    /* 2^200 - 2^100 */ fe51_nsquare(&t,&z2_100_0, 100);
+    /* 2^200 - 2^0 */ fe51_mul(&t,&t,&z2_100_0);
+
+    /* 2^250 - 2^50 */ fe51_nsquare(&t,&t, 50);
+    /* 2^250 - 2^0 */ fe51_mul(&t,&t,&z2_50_0);
+
+    /* 2^255 - 2^5 */ fe51_nsquare(&t,&t,5);
+    /* 2^255 - 21 */ fe51_mul(r,&t,&z11);
+}
+
+#endif