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Commit e6a3a925 authored by Denis Vlasenko's avatar Denis Vlasenko Committed by David S. Miller
Browse files

[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: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 827c3911

arch/i386/crypto/aes-i586-asm.S

+19 −21
Original line number Original line Diff line number Diff line
@@ -257,16 +257,15 @@ aes_enc_blk: 




	sub     $8,%esp		// space for register saves on stack

	sub     $8,%esp		// space for register saves on stack

	add     $16,%ebp	// increment to next round key

	add     $16,%ebp	// increment to next round key

	sub     $10,%r3          

	cmp     $12,%r3

	je      4f              // 10 rounds for 128-bit key

	jb      4f		// 10 rounds for 128-bit key

	add     $32,%ebp

	lea     32(%ebp),%ebp

	sub     $2,%r3

	je      3f		// 12 rounds for 192-bit key

	je      3f              // 12 rounds for 128-bit key

	lea     32(%ebp),%ebp

	add     $32,%ebp





2:	fwd_rnd1( -64(%ebp) ,ft_tab)	// 14 rounds for 256-bit key

2:	fwd_rnd1( -64(%ebp) ,ft_tab)	// 14 rounds for 128-bit key

	fwd_rnd2( -48(%ebp) ,ft_tab)

	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)

	fwd_rnd2( -16(%ebp) ,ft_tab)

4:	fwd_rnd1(    (%ebp) ,ft_tab)	// 10 rounds for 128-bit key

4:	fwd_rnd1(    (%ebp) ,ft_tab)	// 10 rounds for 128-bit key

	fwd_rnd2( +16(%ebp) ,ft_tab)

	fwd_rnd2( +16(%ebp) ,ft_tab)
@@ -336,16 +335,15 @@ aes_dec_blk: 




	sub     $8,%esp		// space for register saves on stack

	sub     $8,%esp		// space for register saves on stack

	sub     $16,%ebp	// increment to next round key

	sub     $16,%ebp	// increment to next round key

	sub     $10,%r3          

	cmp     $12,%r3

	je      4f              // 10 rounds for 128-bit key

	jb      4f		// 10 rounds for 128-bit key

	sub     $32,%ebp

	lea     -32(%ebp),%ebp

	sub     $2,%r3

	je      3f		// 12 rounds for 192-bit key

	je      3f              // 12 rounds for 128-bit key

	lea     -32(%ebp),%ebp

	sub     $32,%ebp





2:	inv_rnd1( +64(%ebp), it_tab)	// 14 rounds for 256-bit key

2:	inv_rnd1( +64(%ebp), it_tab)	// 14 rounds for 128-bit key

	inv_rnd2( +48(%ebp), it_tab)

	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)

	inv_rnd2( +16(%ebp), it_tab)

4:	inv_rnd1(    (%ebp), it_tab)	// 10 rounds for 128-bit key

4:	inv_rnd1(    (%ebp), it_tab)	// 10 rounds for 128-bit key

	inv_rnd2( -16(%ebp), it_tab)

	inv_rnd2( -16(%ebp), it_tab)