From 6f6a6130327bb033730bf36ad826797a1b074317 Mon Sep 17 00:00:00 2001
From: Andy Polyakov <appro@openssl.org>
Date: Thu, 3 Oct 2013 23:08:31 +0200
Subject: aes/asm/bsaes-*.pl: improve decrypt performance.

Improve decrypt performance by 10-20% depending on platform. Thanks
to Jussi Kivilinna for providing valuable hint. Also thanks to Ard
Biesheuvel.
---
 crypto/aes/asm/bsaes-x86_64.pl | 71 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 66 insertions(+), 5 deletions(-)

(limited to 'crypto/aes/asm/bsaes-x86_64.pl')

diff --git a/crypto/aes/asm/bsaes-x86_64.pl b/crypto/aes/asm/bsaes-x86_64.pl
index ceb02b50dd..8cde67681e 100644
--- a/crypto/aes/asm/bsaes-x86_64.pl
+++ b/crypto/aes/asm/bsaes-x86_64.pl
@@ -83,9 +83,9 @@
 # Add decryption procedure. Performance in CPU cycles spent to decrypt
 # one byte out of 4096-byte buffer with 128-bit key is:
 #
-# Core 2	11.0
-# Nehalem	9.16
-# Atom		20.9
+# Core 2	9.83
+# Nehalem	7.74
+# Atom		18.9 (estimated, not measured yet)
 #
 # November 2011.
 #
@@ -456,6 +456,7 @@ sub MixColumns {
 # modified to emit output in order suitable for feeding back to aesenc[last]
 my @x=@_[0..7];
 my @t=@_[8..15];
+my $inv=@_[16];	# optional
 $code.=<<___;
 	pshufd	\$0x93, @x[0], @t[0]	# x0 <<< 32
 	pshufd	\$0x93, @x[1], @t[1]
@@ -497,7 +498,8 @@ $code.=<<___;
 	pxor	@t[4], @t[0]
 	 pshufd	\$0x4E, @x[2], @x[6]
 	pxor	@t[5], @t[1]
-
+___
+$code.=<<___ if (!$inv);
 	pxor	@t[3], @x[4]
 	pxor	@t[7], @x[5]
 	pxor	@t[6], @x[3]
@@ -505,9 +507,20 @@ $code.=<<___;
 	pxor	@t[2], @x[6]
 	 movdqa	@t[1], @x[7]
 ___
+$code.=<<___ if ($inv);
+	pxor	@x[4], @t[3]
+	pxor	@t[7], @x[5]
+	pxor	@x[3], @t[6]
+	 movdqa	@t[0], @x[3]
+	pxor	@t[2], @x[6]
+	 movdqa	@t[6], @x[2]
+	 movdqa	@t[1], @x[7]
+	 movdqa	@x[6], @x[4]
+	 movdqa	@t[3], @x[6]
+___
 }
 
-sub InvMixColumns {
+sub InvMixColumns_orig {
 my @x=@_[0..7];
 my @t=@_[8..15];
 
@@ -661,6 +674,54 @@ $code.=<<___;
 ___
 }
 
+sub InvMixColumns {
+my @x=@_[0..7];
+my @t=@_[8..15];
+
+# Thanks to Jussi Kivilinna for providing pointer to
+#
+# | 0e 0b 0d 09 |   | 02 03 01 01 |   | 05 00 04 00 |
+# | 09 0e 0b 0d | = | 01 02 03 01 | x | 00 05 00 04 |
+# | 0d 09 0e 0b |   | 01 01 02 03 |   | 04 00 05 00 |
+# | 0b 0d 09 0e |   | 03 01 01 02 |   | 00 04 00 05 |
+
+$code.=<<___;
+	# multiplication by 0x05-0x00-0x04-0x00
+	pshufd	\$0x4E, @x[0], @t[0]
+	pshufd	\$0x4E, @x[6], @t[6]
+	pxor	@x[0], @t[0]
+	pshufd	\$0x4E, @x[7], @t[7]
+	pxor	@x[6], @t[6]
+	pshufd	\$0x4E, @x[1], @t[1]
+	pxor	@x[7], @t[7]
+	pshufd	\$0x4E, @x[2], @t[2]
+	pxor	@x[1], @t[1]
+	pshufd	\$0x4E, @x[3], @t[3]
+	pxor	@x[2], @t[2]
+	 pxor	@t[6], @x[0]
+	 pxor	@t[6], @x[1]
+	pshufd	\$0x4E, @x[4], @t[4]
+	pxor	@x[3], @t[3]
+	 pxor	@t[0], @x[2]
+	 pxor	@t[1], @x[3]
+	pshufd	\$0x4E, @x[5], @t[5]
+	pxor	@x[4], @t[4]
+	 pxor	@t[7], @x[1]
+	 pxor	@t[2], @x[4]
+	pxor	@x[5], @t[5]
+
+	 pxor	@t[7], @x[2]
+	 pxor	@t[6], @x[3]
+	 pxor	@t[6], @x[4]
+	 pxor	@t[3], @x[5]
+	 pxor	@t[4], @x[6]
+	 pxor	@t[7], @x[4]
+	 pxor	@t[7], @x[5]
+	 pxor	@t[5], @x[7]
+___
+	&MixColumns	(@x,@t,1);	# flipped 2<->3 and 4<->6
+}
+
 sub aesenc {				# not used
 my @b=@_[0..7];
 my @t=@_[8..15];
-- 
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