[CRYPTO] aes-i586: Nano-optimisation on key length check

Reduce the number of comparisons by one through the use of jb/je.
This patch also corrects the comments regarding the different key
lengths.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 19 insertions, 21 deletions

diff --git a/arch/i386/crypto/aes-i586-asm.S b/arch/i386/crypto/aes-i586-asm.S
index 7b73c67cb4e8..911b15377f2e 100644
--- a/arch/i386/crypto/aes-i586-asm.S
+++ b/arch/i386/crypto/aes-i586-asm.S
@@ -255,18 +255,17 @@ aes_enc_blk:
         xor     8(%ebp),%r4
         xor     12(%ebp),%r5
 
-        sub     $8,%esp           // space for register saves on stack
-        add     $16,%ebp          // increment to next round key
-        sub     $10,%r3          
-        je      4f              // 10 rounds for 128-bit key
-        add     $32,%ebp
-        sub     $2,%r3
-        je      3f              // 12 rounds for 128-bit key
-        add     $32,%ebp
-
-2:      fwd_rnd1( -64(%ebp) ,ft_tab)    // 14 rounds for 128-bit key
+        sub     $8,%esp         // space for register saves on stack
+        add     $16,%ebp        // increment to next round key
+        cmp     $12,%r3
+        jb      4f              // 10 rounds for 128-bit key
+        lea     32(%ebp),%ebp
+        je      3f              // 12 rounds for 192-bit key
+        lea     32(%ebp),%ebp
+
+2:      fwd_rnd1( -64(%ebp) ,ft_tab)    // 14 rounds for 256-bit key
         fwd_rnd2( -48(%ebp) ,ft_tab)
-3:      fwd_rnd1( -32(%ebp) ,ft_tab)    // 12 rounds for 128-bit key
+3:      fwd_rnd1( -32(%ebp) ,ft_tab)    // 12 rounds for 192-bit key
         fwd_rnd2( -16(%ebp) ,ft_tab)
 4:      fwd_rnd1(    (%ebp) ,ft_tab)    // 10 rounds for 128-bit key
         fwd_rnd2( +16(%ebp) ,ft_tab)
@@ -334,18 +333,17 @@ aes_dec_blk:
         xor     8(%ebp),%r4
         xor     12(%ebp),%r5
 
-        sub     $8,%esp         // space for register saves on stack
-        sub     $16,%ebp        // increment to next round key
-        sub     $10,%r3          
-        je      4f              // 10 rounds for 128-bit key
-        sub     $32,%ebp
-        sub     $2,%r3
-        je      3f              // 12 rounds for 128-bit key
-        sub     $32,%ebp
+        sub     $8,%esp         // space for register saves on stack
+        sub     $16,%ebp        // increment to next round key
+        cmp     $12,%r3
+        jb      4f              // 10 rounds for 128-bit key
+        lea     -32(%ebp),%ebp
+        je      3f              // 12 rounds for 192-bit key
+        lea     -32(%ebp),%ebp
 
-2:      inv_rnd1( +64(%ebp), it_tab)    // 14 rounds for 128-bit key
+2:      inv_rnd1( +64(%ebp), it_tab)    // 14 rounds for 256-bit key
         inv_rnd2( +48(%ebp), it_tab)
-3:      inv_rnd1( +32(%ebp), it_tab)    // 12 rounds for 128-bit key
+3:      inv_rnd1( +32(%ebp), it_tab)    // 12 rounds for 192-bit key
         inv_rnd2( +16(%ebp), it_tab)
 4:      inv_rnd1(    (%ebp), it_tab)    // 10 rounds for 128-bit key
         inv_rnd2( -16(%ebp), it_tab)