precompute e(0, 0, key)

adds more performance benefit

1 files changed, 8 insertions, 4 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 13abce7..54d8c86 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -424,13 +424,14 @@ fn encipher_aez_core(key: &Key, tweaks: Tweak, message: &mut [u8]) {
 
     let mut x = Block::NULL;
     let mut e1_eval = E::new(1, 0, key);
+    let e0_eval = E::new(0, 0, key);
 
     for (raw_mi, raw_mi_) in blocks.pairs_mut() {
         e1_eval.advance();
         let mi = Block::from(*raw_mi);
         let mi_ = Block::from(*raw_mi_);
         let wi = mi ^ e1_eval.eval(mi_);
-        let xi = mi_ ^ e(0, 0, key, wi);
+        let xi = mi_ ^ e0_eval.eval(wi);
 
         *raw_mi = wi.0;
         *raw_mi_ = xi.0;
@@ -456,6 +457,7 @@ fn encipher_aez_core(key: &Key, tweaks: Tweak, message: &mut [u8]) {
     let mut y = Block::NULL;
     let mut e2_eval = E::new(2, 0, key);
     let mut e1_eval = E::new(1, 0, key);
+    let e0_eval = E::new(0, 0, key);
     for (raw_wi, raw_xi) in blocks.pairs_mut() {
         e2_eval.advance();
         e1_eval.advance();
@@ -464,7 +466,7 @@ fn encipher_aez_core(key: &Key, tweaks: Tweak, message: &mut [u8]) {
         let s_ = e2_eval.eval(s);
         let yi = wi ^ s_;
         let zi = xi ^ s_;
-        let ci_ = yi ^ e(0, 0, key, zi);
+        let ci_ = yi ^ e0_eval.eval(zi);
         let ci = zi ^ e1_eval.eval(ci_);
 
         *raw_wi = ci.0;
@@ -570,12 +572,13 @@ fn decipher_aez_core(key: &Key, tweaks: Tweak, buffer: &mut [u8]) {
 
     let mut y = Block::NULL;
     let mut e1_eval = E::new(1, 0, key);
+    let e0_eval = E::new(0, 0, key);
     for (raw_ci, raw_ci_) in blocks.pairs_mut() {
         e1_eval.advance();
         let ci = Block::from(*raw_ci);
         let ci_ = Block::from(*raw_ci_);
         let wi = ci ^ e1_eval.eval(ci_);
-        let yi = ci_ ^ e(0, 0, key, wi);
+        let yi = ci_ ^ e0_eval.eval(wi);
 
         *raw_ci = wi.0;
         *raw_ci_ = yi.0;
@@ -601,6 +604,7 @@ fn decipher_aez_core(key: &Key, tweaks: Tweak, buffer: &mut [u8]) {
     let mut x = Block::NULL;
     let mut e2_eval = E::new(2, 0, key);
     let mut e1_eval = E::new(1, 0, key);
+    let e0_eval = E::new(0, 0, key);
     for (raw_wi, raw_yi) in blocks.pairs_mut() {
         e2_eval.advance();
         e1_eval.advance();
@@ -609,7 +613,7 @@ fn decipher_aez_core(key: &Key, tweaks: Tweak, buffer: &mut [u8]) {
         let s_ = e2_eval.eval(s);
         let xi = wi ^ s_;
         let zi = yi ^ s_;
-        let mi_ = xi ^ e(0, 0, key, zi);
+        let mi_ = xi ^ e0_eval.eval(zi);
         let mi = zi ^ e1_eval.eval(mi_);
 
         *raw_wi = mi.0;