Removing non-used fp functions.

Author: armfazh

math/fp448/fp.go

@@ -2,7 +2,6 @@
 package fp448
 
 import (
-	"crypto/subtle"
 	"errors"
 
 	"github.com/cloudflare/circl/internal/conv"
@@ -26,15 +25,6 @@ var p = Elt{
 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 }
-var pMinusOneDivTwo = Elt{
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-	0x00, 0x00, 0x00, 0x80, 0xff, 0xff, 0xff, 0xff,
-	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f,
-}
 
 // P returns the prime modulus 2^448-2^224-1.
 func P() Elt { return p }
@@ -58,23 +48,6 @@ func IsOne(x *Elt) bool { Modp(x); return *x == Elt{1} }
 // Parity returns the last bit of x.
 func Parity(x *Elt) int { Modp(x); return int(x[0] & 1) }
 
-func isLEQ(x, y *Elt) int {
-	i := Size - 1
-	for i > 0 && x[i] == y[i] {
-		i--
-	}
-	return subtle.ConstantTimeLessOrEq(int(x[i]), int(y[i]))
-}
-
-// Abs returns |x| where |x| = x if 0 <= x <= (p-1)/2; otherwise |x|=-x mod p.
-func Abs(x *Elt) {
-	var y Elt
-	Modp(x)
-	Neg(&y, x)
-	b := isLEQ(x, &pMinusOneDivTwo)
-	Cmov(x, &y, uint(1-b))
-}
-
 // SetOne assigns x=1.
 func SetOne(x *Elt) { *x = Elt{1} }