code review 3359042: crypto/elliptic: use a Jacobian transform

crypto/elliptic: use a Jacobian transform

(Speeds up the code about 25x)

[r, 2010-11-30 21:37:24]

wow

http://codereview.appspot.com/3359042/diff/1/src/pkg/crypto/elliptic/elliptic.go
File src/pkg/crypto/elliptic/elliptic.go (right):

http://codereview.appspot.com/3359042/diff/1/src/pkg/crypto/elliptic/elliptic...
src/pkg/crypto/elliptic/elliptic.go:137: func (curve *Curve) doubleJacobian(x,
y, z *big.Int) (*big.Int, *big.Int, *big.Int) {
this func could use a comment

http://codereview.appspot.com/3359042/diff/1/src/pkg/crypto/elliptic/elliptic...
File src/pkg/crypto/elliptic/elliptic_test.go (right):

http://codereview.appspot.com/3359042/diff/1/src/pkg/crypto/elliptic/elliptic...
src/pkg/crypto/elliptic/elliptic_test.go:306: for i := 0; i < b.N; i++ {
there's enough preamble you might start the clock after setup.
(b.ResetTimer;b.StartTimer)

[agl1, 2010-11-30 21:45:25]

http://codereview.appspot.com/3359042/diff/1/src/pkg/crypto/elliptic/elliptic.go
File src/pkg/crypto/elliptic/elliptic.go (right):

http://codereview.appspot.com/3359042/diff/1/src/pkg/crypto/elliptic/elliptic...
src/pkg/crypto/elliptic/elliptic.go:137: func (curve *Curve) doubleJacobian(x,
y, z *big.Int) (*big.Int, *big.Int, *big.Int) {
On 2010/11/30 21:37:24, r wrote:
> this func could use a comment

Done. (And done for addJacobian too.)

http://codereview.appspot.com/3359042/diff/1/src/pkg/crypto/elliptic/elliptic...
File src/pkg/crypto/elliptic/elliptic_test.go (right):

http://codereview.appspot.com/3359042/diff/1/src/pkg/crypto/elliptic/elliptic...
src/pkg/crypto/elliptic/elliptic_test.go:306: for i := 0; i < b.N; i++ {
On 2010/11/30 21:37:24, r wrote:
> there's enough preamble you might start the clock after setup.
> (b.ResetTimer;b.StartTimer)

It doesn't seem to affect the timing much, but done anyway.

[r, 2010-11-30 21:52:35]

LGTM

[agl1, 2010-11-30 21:58:59]

Hello r (cc: golang-dev@googlegroups.com),

I'd like you to review this change.

[agl1, 2010-11-30 21:59:25]

*** Submitted as http://code.google.com/p/go/source/detail?r=23720d3cdf4b ***

crypto/elliptic: use a Jacobian transform

(Speeds up the code about 25x)

R=r
CC=golang-dev
http://codereview.appspot.com/3359042

[agl1, 2010-11-30 22:00:02]

Submitted.