aboutsummaryrefslogtreecommitdiff
path: root/src/ext/ed25519/ref10/ge_msub.q
blob: e3cadd882dd448fa80208ff9889a3c448bc01cb7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
:name:fe:r->X:r->Y:r->Z:r->T:t0:t1:t2:t3:t4:t5:p->X:p->Y:p->Z:p->T:q->yplusx:q->yminusx:q->xy2d:
fe r:var/r=fe:

enter f:enter/f:>X1=fe#11:>Y1=fe#12:>Z1=fe#13:>T1=fe#14:>ypx2=fe#15:>ymx2=fe#16:>xy2d2=fe#17:
return:nofallthrough:<X3=fe#1:<Y3=fe#2:<Z3=fe#3:<T3=fe#4:leave:

h=f+g:<f=fe:<g=fe:>h=fe:asm/fe_add(>h,<f,<g);:
h=f-g:<f=fe:<g=fe:>h=fe:asm/fe_sub(>h,<f,<g);:
h=f*g:<f=fe:<g=fe:>h=fe:asm/fe_mul(>h,<f,<g);:
h=f^2:<f=fe:>h=fe:asm/fe_sq(>h,<f);:
h=2*g:<g=fe:>h=fe:asm/fe_add(>h,<g,<g);:

:

enter ge_msub

fe X1
fe Y1
fe Z1
fe T1
fe ypx2
fe ymx2
fe xy2d2
fe X3
fe Y3
fe Z3
fe T3
fe YpX1
fe YmX1
fe A
fe B
fe C
fe D

YpX1 = Y1+X1
YmX1 = Y1-X1
A = YpX1*ymx2
B = YmX1*ypx2
C = xy2d2*T1
D = 2*Z1
X3 = A-B
Y3 = A+B
Z3 = D-C
T3 = D+C

return