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crypto/sha256.c crypto/sha512.c

PATCH Applied Jean-Luc Cooke 3 participants 8 messages Jan 27, 2004 – Jan 28, 2004

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#2 lore raw

If you take a peek in your/Plumb's crypto/md5.c you've reduced the F1() macro to the identical operation as the new Ch() inline function.

It reduces gcc's tenancy to re-load values in functions such like:
(x & y) ^ (~x & z)
(x & y) ^ (x & z) ^ (y & z)

This works out much nicer:
z ^ (x & (y ^ z))
(x & y) | (z & (x | y))

I've seen this in a few .c files (gcc -S blah.c; vim blah.s)

The Ch() and Maj() operations are used a lot in sha256/512.

JLC

Quoted 14 lines · James Morris
Quoted 10 lines · Jean-Luc Cooke

Optimized the choice and majority fuctions a bit.

Patch:
http://jlcooke.ca/lkml/faster_sha2.patch

Test suite:
http://jlcooke.ca/lkml/faster_sha2.c
build with:
gcc -O3 -s faster_sha2.c -o faster_sha2

What kind of performance improvement does this provide?

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#3 lore raw
Quoted 1 line · On Tue, 27 Jan 2004 15:22:25 -0500 Jean-Luc Cooke <[email protected]>…

The Ch() and Maj() operations are used a lot in sha256/512.

Your analysis is great, but James was really asking for numbers :-)

author
#4 lore raw

I updated the faster_sha2.c to include a quick performance test, same URL.

The Ch/sec and Maj/sec can't be easily compared, however instruction count can to some extent.

http://jlcooke.ca/lkml/faster_sha2_x86.s
http://jlcooke.ca/lkml/faster_sha2_ppc.s
http://jlcooke.ca/lkml/faster_sha2_alpha.s
http://jlcooke.ca/lkml/faster_sha2_sparc.s

Hope this helps, I'll know better next time I ask for patch-blessing. :)

JLC

Quoted 11 lines · David S. Miller
Quoted 1 line · On Tue, 27 Jan 2004 15:22:25 -0500 Jean-Luc Cooke <[email protected]>…

The Ch() and Maj() operations are used a lot in sha256/512.

Your analysis is great, but James was really asking for numbers :-) -
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http://www.certainkey.com
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author
#5 lore raw

Humm,

Pardon my ignorance, but does silence mean "yes"?

Didn't see any changes to http://samba.org/~jamesm/crypto/

JLC

Quoted 38 lines · Jean-Luc Cooke

I updated the faster_sha2.c to include a quick performance test, same URL.

The Ch/sec and Maj/sec can't be easily compared, however instruction count can to some extent.

http://jlcooke.ca/lkml/faster_sha2_x86.s
http://jlcooke.ca/lkml/faster_sha2_ppc.s
http://jlcooke.ca/lkml/faster_sha2_alpha.s
http://jlcooke.ca/lkml/faster_sha2_sparc.s

Hope this helps, I'll know better next time I ask for patch-blessing. :)

JLC

Quoted 11 lines · David S. Miller
Quoted 1 line · On Tue, 27 Jan 2004 15:22:25 -0500 Jean-Luc Cooke <[email protected]>…

The Ch() and Maj() operations are used a lot in sha256/512.

Your analysis is great, but James was really asking for numbers :-) -
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More majordomo info at http://vger.kernel.org/majordomo-info.html
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-
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Signature · 4 lines
http://www.certainkey.com
Suite 4560 CTTC
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#6 lore raw
Quoted 1 line · Jean-Luc Cooke

Pardon my ignorance, but does silence mean "yes"?

No, but the patch looks fine to me and passes the test vectors.

Dave, I've included it below.

- James

Signature · 39 lines
James Morris
<[email protected]>

diff -Naur linux-2.6.1/crypto/sha256.c linux-2.6.1-patched/crypto/sha256.c
--- linux-2.6.1/crypto/sha256.c	2004-01-09 01:59:26.000000000 -0500
+++ linux-2.6.1-patched/crypto/sha256.c	2004-01-27 14:22:00.000000000 -0500
@@ -34,12 +34,12 @@
 
 static inline u32 Ch(u32 x, u32 y, u32 z)
 {
-	return ((x & y) ^ (~x & z));
+	return z ^ (x & (y ^ z));
 }
 
 static inline u32 Maj(u32 x, u32 y, u32 z)
 {
-	return ((x & y) ^ (x & z) ^ (y & z));
+	return (x & y) | (z & (x | y));
 }
 
 static inline u32 RORu32(u32 x, u32 y)
diff -Naur linux-2.6.1/crypto/sha512.c linux-2.6.1-patched/crypto/sha512.c
--- linux-2.6.1/crypto/sha512.c	2004-01-09 02:00:03.000000000 -0500
+++ linux-2.6.1-patched/crypto/sha512.c	2004-01-27 14:22:26.000000000 -0500
@@ -34,12 +34,12 @@
 
 static inline u64 Ch(u64 x, u64 y, u64 z)
 {
-        return ((x & y) ^ (~x & z));
+        return z ^ (x & (y ^ z));
 }
 
 static inline u64 Maj(u64 x, u64 y, u64 z)
 {
-        return ((x & y) ^ (x & z) ^ (y & z));
+        return (x & y) | (z & (x | y));
 }
 
 static inline u64 RORu64(u64 x, u64 y)
Applied
#7 lore raw
Quoted 7 lines · On Wed, 28 Jan 2004 17:08:58 -0500 (EST) James Morris <[email protected]>…
Quoted 1 line · Jean-Luc Cooke

Pardon my ignorance, but does silence mean "yes"?

No, but the patch looks fine to me and passes the test vectors.

Dave, I've included it below.

Applied, thanks guys.