curve25519: replace hacl64 with fiat64

For now, it's faster:

hacl64: 109782 cycles per call
fiat64: 108984 cycles per call

It's quite possible this commit will be reverted with nice changes from
INRIA, though.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 0 insertions, 739 deletions

diff --git a/src/crypto/curve25519-hacl64.h b/src/crypto/curve25519-hacl64.h
deleted file mode 100644
index e3ddea9..0000000
--- a/src/crypto/curve25519-hacl64.h
+++ /dev/null
@@ -1,739 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2016-2017 INRIA and Microsoft Corporation.
- * Copyright (C) 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
- *
- * This is a machine-generated formally verified implementation of curve25519 DH from:
- * https://github.com/mitls/hacl-star
- */
-
-typedef __uint128_t u128;
-static __always_inline u64 u64_eq_mask(u64 x, u64 y)
-{
-	x = ~(x ^ y);
-	x &= x << 32;
-	x &= x << 16;
-	x &= x << 8;
-	x &= x << 4;
-	x &= x << 2;
-	x &= x << 1;
-	return ((s64)x) >> 63;
-}
-
-static __always_inline u64 u64_gte_mask(u64 x, u64 y)
-{
-	u64 low63 = ~((u64)((s64)((s64)(x & 0x7fffffffffffffffLLU) - (s64)(y & 0x7fffffffffffffffLLU)) >> 63));
-	u64 high_bit = ~((u64)((s64)((s64)(x & 0x8000000000000000LLU) - (s64)(y & 0x8000000000000000LLU)) >> 63));
-	return low63 & high_bit;
-}
-
-static __always_inline void modulo_carry_top(u64 *b)
-{
-	u64 b4 = b[4];
-	u64 b0 = b[0];
-	u64 b4_ = b4 & 0x7ffffffffffffLLU;
-	u64 b0_ = b0 + 19 * (b4 >> 51);
-	b[4] = b4_;
-	b[0] = b0_;
-}
-
-static __always_inline void fproduct_copy_from_wide_(u64 *output, u128 *input)
-{
-	{
-		u128 xi = input[0];
-		output[0] = ((u64)(xi));
-	}
-	{
-		u128 xi = input[1];
-		output[1] = ((u64)(xi));
-	}
-	{
-		u128 xi = input[2];
-		output[2] = ((u64)(xi));
-	}
-	{
-		u128 xi = input[3];
-		output[3] = ((u64)(xi));
-	}
-	{
-		u128 xi = input[4];
-		output[4] = ((u64)(xi));
-	}
-}
-
-static __always_inline void fproduct_sum_scalar_multiplication_(u128 *output, u64 *input, u64 s)
-{
-	u32 i;
-	for (i = 0; i < 5; ++i) {
-		u128 xi = output[i];
-		u64 yi = input[i];
-		output[i] = ((xi) + (((u128)(yi) * (s))));
-	}
-}
-
-static __always_inline void fproduct_carry_wide_(u128 *tmp)
-{
-	u32 i;
-	for (i = 0; i < 4; ++i) {
-		u32 ctr = i;
-		u128 tctr = tmp[ctr];
-		u128 tctrp1 = tmp[ctr + 1];
-		u64 r0 = ((u64)(tctr)) & 0x7ffffffffffffLLU;
-		u128 c = ((tctr) >> (51));
-		tmp[ctr] = ((u128)(r0));
-		tmp[ctr + 1] = ((tctrp1) + (c));
-	}
-}
-
-static __always_inline void fmul_shift_reduce(u64 *output)
-{
-	u64 tmp = output[4];
-	u64 b0;
-	{
-		u32 ctr = 5 - 0 - 1;
-		u64 z = output[ctr - 1];
-		output[ctr] = z;
-	}
-	{
-		u32 ctr = 5 - 1 - 1;
-		u64 z = output[ctr - 1];
-		output[ctr] = z;
-	}
-	{
-		u32 ctr = 5 - 2 - 1;
-		u64 z = output[ctr - 1];
-		output[ctr] = z;
-	}
-	{
-		u32 ctr = 5 - 3 - 1;
-		u64 z = output[ctr - 1];
-		output[ctr] = z;
-	}
-	output[0] = tmp;
-	b0 = output[0];
-	output[0] = 19 * b0;
-}
-
-static __always_inline void fmul_mul_shift_reduce_(u128 *output, u64 *input, u64 *input21)
-{
-	u32 i;
-	u64 input2i;
-	{
-		u64 input2i = input21[0];
-		fproduct_sum_scalar_multiplication_(output, input, input2i);
-		fmul_shift_reduce(input);
-	}
-	{
-		u64 input2i = input21[1];
-		fproduct_sum_scalar_multiplication_(output, input, input2i);
-		fmul_shift_reduce(input);
-	}
-	{
-		u64 input2i = input21[2];
-		fproduct_sum_scalar_multiplication_(output, input, input2i);
-		fmul_shift_reduce(input);
-	}
-	{
-		u64 input2i = input21[3];
-		fproduct_sum_scalar_multiplication_(output, input, input2i);
-		fmul_shift_reduce(input);
-	}
-	i = 4;
-	input2i = input21[i];
-	fproduct_sum_scalar_multiplication_(output, input, input2i);
-}
-
-static __always_inline void fmul_fmul(u64 *output, u64 *input, u64 *input21)
-{
-	u64 tmp[5];
-	memcpy(tmp, input, 5 * sizeof(*input));
-	{
-		u128 b4;
-		u128 b0;
-		u128 b4_;
-		u128 b0_;
-		u64 i0;
-		u64 i1;
-		u64 i0_;
-		u64 i1_;
-		u128 t[5];
-		{
-			u32 _i;
-			for (_i = 0; _i < 5; ++_i)
-				t[_i] = ((u128)(0));
-		}
-		fmul_mul_shift_reduce_(t, tmp, input21);
-		fproduct_carry_wide_(t);
-		b4 = t[4];
-		b0 = t[0];
-		b4_ = ((b4) & (((u128)(0x7ffffffffffffLLU))));
-		b0_ = ((b0) + (((u128)(19) * (((u64)(((b4) >> (51))))))));
-		t[4] = b4_;
-		t[0] = b0_;
-		fproduct_copy_from_wide_(output, t);
-		i0 = output[0];
-		i1 = output[1];
-		i0_ = i0 & 0x7ffffffffffffLLU;
-		i1_ = i1 + (i0 >> 51);
-		output[0] = i0_;
-		output[1] = i1_;
-	}
-}
-
-static __always_inline void fsquare_fsquare__(u128 *tmp, u64 *output)
-{
-	u64 r0 = output[0];
-	u64 r1 = output[1];
-	u64 r2 = output[2];
-	u64 r3 = output[3];
-	u64 r4 = output[4];
-	u64 d0 = r0 * 2;
-	u64 d1 = r1 * 2;
-	u64 d2 = r2 * 2 * 19;
-	u64 d419 = r4 * 19;
-	u64 d4 = d419 * 2;
-	u128 s0 = ((((((u128)(r0) * (r0))) + (((u128)(d4) * (r1))))) + (((u128)(d2) * (r3))));
-	u128 s1 = ((((((u128)(d0) * (r1))) + (((u128)(d4) * (r2))))) + (((u128)(r3 * 19) * (r3))));
-	u128 s2 = ((((((u128)(d0) * (r2))) + (((u128)(r1) * (r1))))) + (((u128)(d4) * (r3))));
-	u128 s3 = ((((((u128)(d0) * (r3))) + (((u128)(d1) * (r2))))) + (((u128)(r4) * (d419))));
-	u128 s4 = ((((((u128)(d0) * (r4))) + (((u128)(d1) * (r3))))) + (((u128)(r2) * (r2))));
-	tmp[0] = s0;
-	tmp[1] = s1;
-	tmp[2] = s2;
-	tmp[3] = s3;
-	tmp[4] = s4;
-}
-
-static __always_inline void fsquare_fsquare_(u128 *tmp, u64 *output)
-{
-	u128 b4;
-	u128 b0;
-	u128 b4_;
-	u128 b0_;
-	u64 i0;
-	u64 i1;
-	u64 i0_;
-	u64 i1_;
-	fsquare_fsquare__(tmp, output);
-	fproduct_carry_wide_(tmp);
-	b4 = tmp[4];
-	b0 = tmp[0];
-	b4_ = ((b4) & (((u128)(0x7ffffffffffffLLU))));
-	b0_ = ((b0) + (((u128)(19) * (((u64)(((b4) >> (51))))))));
-	tmp[4] = b4_;
-	tmp[0] = b0_;
-	fproduct_copy_from_wide_(output, tmp);
-	i0 = output[0];
-	i1 = output[1];
-	i0_ = i0 & 0x7ffffffffffffLLU;
-	i1_ = i1 + (i0 >> 51);
-	output[0] = i0_;
-	output[1] = i1_;
-}
-
-static __always_inline void fsquare_fsquare_times_(u64 *input, u128 *tmp, u32 count1)
-{
-	u32 i;
-	fsquare_fsquare_(tmp, input);
-	for (i = 1; i < count1; ++i)
-		fsquare_fsquare_(tmp, input);
-}
-
-static __always_inline void fsquare_fsquare_times(u64 *output, u64 *input, u32 count1)
-{
-	u128 t[5];
-	{
-		u32 _i;
-		for (_i = 0; _i < 5; ++_i)
-			t[_i] = ((u128)(0));
-	}
-	memcpy(output, input, 5 * sizeof(*input));
-	fsquare_fsquare_times_(output, t, count1);
-}
-
-static __always_inline void fsquare_fsquare_times_inplace(u64 *output, u32 count1)
-{
-	u128 t[5];
-	{
-		u32 _i;
-		for (_i = 0; _i < 5; ++_i)
-			t[_i] = ((u128)(0));
-	}
-	fsquare_fsquare_times_(output, t, count1);
-}
-
-static __always_inline void crecip_crecip(u64 *out, u64 *z)
-{
-	u64 buf[20] = { 0 };
-	u64 *a0 = buf;
-	u64 *t00 = buf + 5;
-	u64 *b0 = buf + 10;
-	u64 *t01;
-	u64 *b1;
-	u64 *c0;
-	u64 *a;
-	u64 *t0;
-	u64 *b;
-	u64 *c;
-	fsquare_fsquare_times(a0, z, 1);
-	fsquare_fsquare_times(t00, a0, 2);
-	fmul_fmul(b0, t00, z);
-	fmul_fmul(a0, b0, a0);
-	fsquare_fsquare_times(t00, a0, 1);
-	fmul_fmul(b0, t00, b0);
-	fsquare_fsquare_times(t00, b0, 5);
-	t01 = buf + 5;
-	b1 = buf + 10;
-	c0 = buf + 15;
-	fmul_fmul(b1, t01, b1);
-	fsquare_fsquare_times(t01, b1, 10);
-	fmul_fmul(c0, t01, b1);
-	fsquare_fsquare_times(t01, c0, 20);
-	fmul_fmul(t01, t01, c0);
-	fsquare_fsquare_times_inplace(t01, 10);
-	fmul_fmul(b1, t01, b1);
-	fsquare_fsquare_times(t01, b1, 50);
-	a = buf;
-	t0 = buf + 5;
-	b = buf + 10;
-	c = buf + 15;
-	fmul_fmul(c, t0, b);
-	fsquare_fsquare_times(t0, c, 100);
-	fmul_fmul(t0, t0, c);
-	fsquare_fsquare_times_inplace(t0, 50);
-	fmul_fmul(t0, t0, b);
-	fsquare_fsquare_times_inplace(t0, 5);
-	fmul_fmul(out, t0, a);
-}
-
-static __always_inline void fsum(u64 *a, u64 *b)
-{
-	u32 i;
-	for (i = 0; i < 5; ++i) {
-		u64 xi = a[i];
-		u64 yi = b[i];
-		a[i] = xi + yi;
-	}
-}
-
-static __always_inline void fdifference(u64 *a, u64 *b)
-{
-	u64 tmp[5] = { 0 };
-	u64 b0;
-	u64 b1;
-	u64 b2;
-	u64 b3;
-	u64 b4;
-	memcpy(tmp, b, 5 * sizeof(*b));
-	b0 = tmp[0];
-	b1 = tmp[1];
-	b2 = tmp[2];
-	b3 = tmp[3];
-	b4 = tmp[4];
-	tmp[0] = b0 + 0x3fffffffffff68LLU;
-	tmp[1] = b1 + 0x3ffffffffffff8LLU;
-	tmp[2] = b2 + 0x3ffffffffffff8LLU;
-	tmp[3] = b3 + 0x3ffffffffffff8LLU;
-	tmp[4] = b4 + 0x3ffffffffffff8LLU;
-	{
-		u64 xi = a[0];
-		u64 yi = tmp[0];
-		a[0] = yi - xi;
-	}
-	{
-		u64 xi = a[1];
-		u64 yi = tmp[1];
-		a[1] = yi - xi;
-	}
-	{
-		u64 xi = a[2];
-		u64 yi = tmp[2];
-		a[2] = yi - xi;
-	}
-	{
-		u64 xi = a[3];
-		u64 yi = tmp[3];
-		a[3] = yi - xi;
-	}
-	{
-		u64 xi = a[4];
-		u64 yi = tmp[4];
-		a[4] = yi - xi;
-	}
-}
-
-static __always_inline void fscalar(u64 *output, u64 *b, u64 s)
-{
-	u128 tmp[5];
-	u128 b4;
-	u128 b0;
-	u128 b4_;
-	u128 b0_;
-	{
-		u64 xi = b[0];
-		tmp[0] = ((u128)(xi) * (s));
-	}
-	{
-		u64 xi = b[1];
-		tmp[1] = ((u128)(xi) * (s));
-	}
-	{
-		u64 xi = b[2];
-		tmp[2] = ((u128)(xi) * (s));
-	}
-	{
-		u64 xi = b[3];
-		tmp[3] = ((u128)(xi) * (s));
-	}
-	{
-		u64 xi = b[4];
-		tmp[4] = ((u128)(xi) * (s));
-	}
-	fproduct_carry_wide_(tmp);
-	b4 = tmp[4];
-	b0 = tmp[0];
-	b4_ = ((b4) & (((u128)(0x7ffffffffffffLLU))));
-	b0_ = ((b0) + (((u128)(19) * (((u64)(((b4) >> (51))))))));
-	tmp[4] = b4_;
-	tmp[0] = b0_;
-	fproduct_copy_from_wide_(output, tmp);
-}
-
-static __always_inline void fmul(u64 *output, u64 *a, u64 *b)
-{
-	fmul_fmul(output, a, b);
-}
-
-static __always_inline void crecip(u64 *output, u64 *input)
-{
-	crecip_crecip(output, input);
-}
-
-static __always_inline void point_swap_conditional_step(u64 *a, u64 *b, u64 swap1, u32 ctr)
-{
-	u32 i = ctr - 1;
-	u64 ai = a[i];
-	u64 bi = b[i];
-	u64 x = swap1 & (ai ^ bi);
-	u64 ai1 = ai ^ x;
-	u64 bi1 = bi ^ x;
-	a[i] = ai1;
-	b[i] = bi1;
-}
-
-static __always_inline void point_swap_conditional_(u64 *a, u64 *b, u64 swap1, u32 ctr)
-{
-	u32 i;
-	for (i = ctr; i > 0; --i)
-		point_swap_conditional_step(a, b, swap1, i);
-}
-
-static __always_inline void point_swap_conditional(u64 *a, u64 *b, u64 iswap)
-{
-	u64 swap1 = 0 - iswap;
-	point_swap_conditional_(a, b, swap1, 5);
-	point_swap_conditional_(a + 5, b + 5, swap1, 5);
-}
-
-static __always_inline void point_copy(u64 *output, u64 *input)
-{
-	memcpy(output, input, 5 * sizeof(*input));
-	memcpy(output + 5, input + 5, 5 * sizeof(*input));
-}
-
-static __always_inline void addanddouble_fmonty(u64 *pp, u64 *ppq, u64 *p, u64 *pq, u64 *qmqp)
-{
-	u64 *qx = qmqp;
-	u64 *x2 = pp;
-	u64 *z2 = pp + 5;
-	u64 *x3 = ppq;
-	u64 *z3 = ppq + 5;
-	u64 *x = p;
-	u64 *z = p + 5;
-	u64 *xprime = pq;
-	u64 *zprime = pq + 5;
-	u64 buf[40] = { 0 };
-	u64 *origx = buf;
-	u64 *origxprime0 = buf + 5;
-	u64 *xxprime0;
-	u64 *zzprime0;
-	u64 *origxprime;
-	xxprime0 = buf + 25;
-	zzprime0 = buf + 30;
-	memcpy(origx, x, 5 * sizeof(*x));
-	fsum(x, z);
-	fdifference(z, origx);
-	memcpy(origxprime0, xprime, 5 * sizeof(*xprime));
-	fsum(xprime, zprime);
-	fdifference(zprime, origxprime0);
-	fmul(xxprime0, xprime, z);
-	fmul(zzprime0, x, zprime);
-	origxprime = buf + 5;
-	{
-		u64 *xx0;
-		u64 *zz0;
-		u64 *xxprime;
-		u64 *zzprime;
-		u64 *zzzprime;
-		xx0 = buf + 15;
-		zz0 = buf + 20;
-		xxprime = buf + 25;
-		zzprime = buf + 30;
-		zzzprime = buf + 35;
-		memcpy(origxprime, xxprime, 5 * sizeof(*xxprime));
-		fsum(xxprime, zzprime);
-		fdifference(zzprime, origxprime);
-		fsquare_fsquare_times(x3, xxprime, 1);
-		fsquare_fsquare_times(zzzprime, zzprime, 1);
-		fmul(z3, zzzprime, qx);
-		fsquare_fsquare_times(xx0, x, 1);
-		fsquare_fsquare_times(zz0, z, 1);
-		{
-			u64 *zzz;
-			u64 *xx;
-			u64 *zz;
-			u64 scalar;
-			zzz = buf + 10;
-			xx = buf + 15;
-			zz = buf + 20;
-			fmul(x2, xx, zz);
-			fdifference(zz, xx);
-			scalar = 121665;
-			fscalar(zzz, zz, scalar);
-			fsum(zzz, xx);
-			fmul(z2, zzz, zz);
-		}
-	}
-}
-
-static __always_inline void ladder_smallloop_cmult_small_loop_step(u64 *nq, u64 *nqpq, u64 *nq2, u64 *nqpq2, u64 *q, u8 byt)
-{
-	u64 bit0 = (u64)(byt >> 7);
-	u64 bit;
-	point_swap_conditional(nq, nqpq, bit0);
-	addanddouble_fmonty(nq2, nqpq2, nq, nqpq, q);
-	bit = (u64)(byt >> 7);
-	point_swap_conditional(nq2, nqpq2, bit);
-}
-
-static __always_inline void ladder_smallloop_cmult_small_loop_double_step(u64 *nq, u64 *nqpq, u64 *nq2, u64 *nqpq2, u64 *q, u8 byt)
-{
-	u8 byt1;
-	ladder_smallloop_cmult_small_loop_step(nq, nqpq, nq2, nqpq2, q, byt);
-	byt1 = byt << 1;
-	ladder_smallloop_cmult_small_loop_step(nq2, nqpq2, nq, nqpq, q, byt1);
-}
-
-static __always_inline void ladder_smallloop_cmult_small_loop(u64 *nq, u64 *nqpq, u64 *nq2, u64 *nqpq2, u64 *q, u8 byt, u32 i)
-{
-	while (i--) {
-		ladder_smallloop_cmult_small_loop_double_step(nq, nqpq, nq2, nqpq2, q, byt);
-		byt <<= 2;
-	}
-}
-
-static __always_inline void ladder_bigloop_cmult_big_loop(u8 *n1, u64 *nq, u64 *nqpq, u64 *nq2, u64 *nqpq2, u64 *q, u32 i)
-{
-	while (i--) {
-		u8 byte = n1[i];
-		ladder_smallloop_cmult_small_loop(nq, nqpq, nq2, nqpq2, q, byte, 4);
-	}
-}
-
-static __always_inline void ladder_cmult(u64 *result, u8 *n1, u64 *q)
-{
-	u64 point_buf[40] = { 0 };
-	u64 *nq = point_buf;
-	u64 *nqpq = point_buf + 10;
-	u64 *nq2 = point_buf + 20;
-	u64 *nqpq2 = point_buf + 30;
-	point_copy(nqpq, q);
-	nq[0] = 1;
-	ladder_bigloop_cmult_big_loop(n1, nq, nqpq, nq2, nqpq2, q, 32);
-	point_copy(result, nq);
-}
-
-static __always_inline void format_fexpand(u64 *output, const u8 *input)
-{
-	const u8 *x00 = input + 6;
-	const u8 *x01 = input + 12;
-	const u8 *x02 = input + 19;
-	const u8 *x0 = input + 24;
-	u64 i0, i1, i2, i3, i4, output0, output1, output2, output3, output4;
-	i0 = le64_to_cpup((__force __le64 *)input);
-	i1 = le64_to_cpup((__force __le64 *)x00);
-	i2 = le64_to_cpup((__force __le64 *)x01);
-	i3 = le64_to_cpup((__force __le64 *)x02);
-	i4 = le64_to_cpup((__force __le64 *)x0);
-	output0 = i0 & 0x7ffffffffffffLLU;
-	output1 = i1 >> 3 & 0x7ffffffffffffLLU;
-	output2 = i2 >> 6 & 0x7ffffffffffffLLU;
-	output3 = i3 >> 1 & 0x7ffffffffffffLLU;
-	output4 = i4 >> 12 & 0x7ffffffffffffLLU;
-	output[0] = output0;
-	output[1] = output1;
-	output[2] = output2;
-	output[3] = output3;
-	output[4] = output4;
-}
-
-static __always_inline void format_fcontract_first_carry_pass(u64 *input)
-{
-	u64 t0 = input[0];
-	u64 t1 = input[1];
-	u64 t2 = input[2];
-	u64 t3 = input[3];
-	u64 t4 = input[4];
-	u64 t1_ = t1 + (t0 >> 51);
-	u64 t0_ = t0 & 0x7ffffffffffffLLU;
-	u64 t2_ = t2 + (t1_ >> 51);
-	u64 t1__ = t1_ & 0x7ffffffffffffLLU;
-	u64 t3_ = t3 + (t2_ >> 51);
-	u64 t2__ = t2_ & 0x7ffffffffffffLLU;
-	u64 t4_ = t4 + (t3_ >> 51);
-	u64 t3__ = t3_ & 0x7ffffffffffffLLU;
-	input[0] = t0_;
-	input[1] = t1__;
-	input[2] = t2__;
-	input[3] = t3__;
-	input[4] = t4_;
-}
-
-static __always_inline void format_fcontract_first_carry_full(u64 *input)
-{
-	format_fcontract_first_carry_pass(input);
-	modulo_carry_top(input);
-}
-
-static __always_inline void format_fcontract_second_carry_pass(u64 *input)
-{
-	u64 t0 = input[0];
-	u64 t1 = input[1];
-	u64 t2 = input[2];
-	u64 t3 = input[3];
-	u64 t4 = input[4];
-	u64 t1_ = t1 + (t0 >> 51);
-	u64 t0_ = t0 & 0x7ffffffffffffLLU;
-	u64 t2_ = t2 + (t1_ >> 51);
-	u64 t1__ = t1_ & 0x7ffffffffffffLLU;
-	u64 t3_ = t3 + (t2_ >> 51);
-	u64 t2__ = t2_ & 0x7ffffffffffffLLU;
-	u64 t4_ = t4 + (t3_ >> 51);
-	u64 t3__ = t3_ & 0x7ffffffffffffLLU;
-	input[0] = t0_;
-	input[1] = t1__;
-	input[2] = t2__;
-	input[3] = t3__;
-	input[4] = t4_;
-}
-
-static __always_inline void format_fcontract_second_carry_full(u64 *input)
-{
-	u64 i0;
-	u64 i1;
-	u64 i0_;
-	u64 i1_;
-	format_fcontract_second_carry_pass(input);
-	modulo_carry_top(input);
-	i0 = input[0];
-	i1 = input[1];
-	i0_ = i0 & 0x7ffffffffffffLLU;
-	i1_ = i1 + (i0 >> 51);
-	input[0] = i0_;
-	input[1] = i1_;
-}
-
-static __always_inline void format_fcontract_trim(u64 *input)
-{
-	u64 a0 = input[0];
-	u64 a1 = input[1];
-	u64 a2 = input[2];
-	u64 a3 = input[3];
-	u64 a4 = input[4];
-	u64 mask0 = u64_gte_mask(a0, 0x7ffffffffffedLLU);
-	u64 mask1 = u64_eq_mask(a1, 0x7ffffffffffffLLU);
-	u64 mask2 = u64_eq_mask(a2, 0x7ffffffffffffLLU);
-	u64 mask3 = u64_eq_mask(a3, 0x7ffffffffffffLLU);
-	u64 mask4 = u64_eq_mask(a4, 0x7ffffffffffffLLU);
-	u64 mask = (((mask0 & mask1) & mask2) & mask3) & mask4;
-	u64 a0_ = a0 - (0x7ffffffffffedLLU & mask);
-	u64 a1_ = a1 - (0x7ffffffffffffLLU & mask);
-	u64 a2_ = a2 - (0x7ffffffffffffLLU & mask);
-	u64 a3_ = a3 - (0x7ffffffffffffLLU & mask);
-	u64 a4_ = a4 - (0x7ffffffffffffLLU & mask);
-	input[0] = a0_;
-	input[1] = a1_;
-	input[2] = a2_;
-	input[3] = a3_;
-	input[4] = a4_;
-}
-
-static __always_inline void format_fcontract_store(u8 *output, u64 *input)
-{
-	u64 t0 = input[0];
-	u64 t1 = input[1];
-	u64 t2 = input[2];
-	u64 t3 = input[3];
-	u64 t4 = input[4];
-	u64 o0 = t1 << 51 | t0;
-	u64 o1 = t2 << 38 | t1 >> 13;
-	u64 o2 = t3 << 25 | t2 >> 26;
-	u64 o3 = t4 << 12 | t3 >> 39;
-	u8 *b0 = output;
-	u8 *b1 = output + 8;
-	u8 *b2 = output + 16;
-	u8 *b3 = output + 24;
-	*(__force __le64 *)b0 = cpu_to_le64(o0);
-	*(__force __le64 *)b1 = cpu_to_le64(o1);
-	*(__force __le64 *)b2 = cpu_to_le64(o2);
-	*(__force __le64 *)b3 = cpu_to_le64(o3);
-}
-
-static __always_inline void format_fcontract(u8 *output, u64 *input)
-{
-	format_fcontract_first_carry_full(input);
-	format_fcontract_second_carry_full(input);
-	format_fcontract_trim(input);
-	format_fcontract_store(output, input);
-}
-
-static __always_inline void format_scalar_of_point(u8 *scalar, u64 *point)
-{
-	u64 *x = point;
-	u64 *z = point + 5;
-	u64 buf[10] __aligned(32) = { 0 };
-	u64 *zmone = buf;
-	u64 *sc = buf + 5;
-	crecip(zmone, z);
-	fmul(sc, x, zmone);
-	format_fcontract(scalar, sc);
-}
-
-static void curve25519_generic(u8 mypublic[CURVE25519_POINT_SIZE], const u8 secret[CURVE25519_POINT_SIZE], const u8 basepoint[CURVE25519_POINT_SIZE])
-{
-	u64 buf0[10] __aligned(32) = { 0 };
-	u64 *x0 = buf0;
-	u64 *z = buf0 + 5;
-	u64 *q;
-	format_fexpand(x0, basepoint);
-	z[0] = 1;
-	q = buf0;
-	{
-		u8 e[32] __aligned(32) = { 0 };
-		u8 *scalar;
-		memcpy(e, secret, 32);
-		normalize_secret(e);
-		scalar = e;
-		{
-			u64 buf[15] = { 0 };
-			u64 *nq = buf;
-			u64 *x = nq;
-			x[0] = 1;
-			ladder_cmult(nq, scalar, q);
-			format_scalar_of_point(mypublic, nq);
-			memzero_explicit(buf, sizeof(buf));
-		}
-		memzero_explicit(e, sizeof(e));
-	}
-	memzero_explicit(buf0, sizeof(buf0));
-}