ed25519/ref10/ge_msub.q

   1 :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:
   2 fe r:var/r=fe:
   3
   4 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:
   5 return:nofallthrough:<X3=fe#1:<Y3=fe#2:<Z3=fe#3:<T3=fe#4:leave:
   6
   7 h=f+g:<f=fe:<g=fe:>h=fe:asm/fe_add(>h,<f,<g);:
   8 h=f-g:<f=fe:<g=fe:>h=fe:asm/fe_sub(>h,<f,<g);:
   9 h=f*g:<f=fe:<g=fe:>h=fe:asm/fe_mul(>h,<f,<g);:
  10 h=f^2:<f=fe:>h=fe:asm/fe_sq(>h,<f);:
  11 h=2*g:<g=fe:>h=fe:asm/fe_add(>h,<g,<g);:
  12
  13 :
  14
  15 enter ge_msub
  16
  17 fe X1
  18 fe Y1
  19 fe Z1
  20 fe T1
  21 fe ypx2
  22 fe ymx2
  23 fe xy2d2
  24 fe X3
  25 fe Y3
  26 fe Z3
  27 fe T3
  28 fe YpX1
  29 fe YmX1
  30 fe A
  31 fe B
  32 fe C
  33 fe D
  34
  35 YpX1 = Y1+X1
  36 YmX1 = Y1-X1
  37 A = YpX1*ymx2
  38 B = YmX1*ypx2
  39 C = xy2d2*T1
  40 D = 2*Z1
  41 X3 = A-B
  42 Y3 = A+B
  43 Z3 = D-C
  44 T3 = D+C
  45
  46 return