From: Andy Polyakov <appro@openssl.org>
Date: Tue, 30 Nov 2004 15:46:46 +0000 (+0000)
Subject: Add 0.9.7 specific comments to RC4 assembler modules.
X-Git-Tag: BEN_FIPS_TEST_6~14^2~14
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=b7b46c9a87c9fe7275a84c5ecb9f5f3459d7b307;p=oweals%2Fopenssl.git

Add 0.9.7 specific comments to RC4 assembler modules.
---

diff --git a/crypto/rc4/asm/rc4-586.pl b/crypto/rc4/asm/rc4-586.pl
index 977a9f1237..07b2bc6fcd 100644
--- a/crypto/rc4/asm/rc4-586.pl
+++ b/crypto/rc4/asm/rc4-586.pl
@@ -1,7 +1,7 @@
 #!/usr/local/bin/perl
 
 # At some point it became apparent that the original SSLeay RC4
-# assembler implementation performs suboptimal on latest IA-32
+# assembler implementation performs suboptimaly on latest IA-32
 # microarchitectures. After re-tuning performance has changed as
 # following:
 #
@@ -15,10 +15,12 @@
 #	In other words code performing further 13% faster on AMD
 #	would perform almost 2 times slower on Intel PIII...
 #	For reference! This code delivers ~80% of rc4-amd64.pl
-#	performance on same Opteron machine.
+#	performance on the same Opteron machine.
 # (**)	This number requires compressed key schedule set up by
-#	RC4_set_key, see commentary section in rc4_skey.c for
-#	further details.
+#	RC4_set_key and therefore doesn't apply to 0.9.7 [option for
+#	compressed key schedule is implemented in 0.9.8 and later,
+#	see commentary section in rc4_skey.c for further details].
+#
 #					<appro@fy.chalmers.se>
 
 push(@INC,"perlasm","../../perlasm");
@@ -130,6 +132,8 @@ sub RC4
 	 &add(	$d,	8);
 
 	# detect compressed schedule, see commentary section in rc4_skey.c...
+	# in 0.9.7 context ~50 bytes below RC4_CHAR label remain redundant,
+	# as compressed key schedule is set up in 0.9.8 and later.
 	&cmp(&DWP(256,$d),-1);
 	&je(&label("RC4_CHAR"));
 
@@ -190,7 +194,8 @@ sub RC4
 	&jmp(&label("finished"));
 
 	&align(16);
-	# this is essentially Intel P4 specific codepath, see rc4_skey.c...
+	# this is essentially Intel P4 specific codepath, see rc4_skey.c,
+	# and is engaged in 0.9.8 and later context...
 	&set_label("RC4_CHAR");
 
 	&lea	($ty,&DWP(0,$in,$ty));
diff --git a/crypto/rc4/asm/rc4-amd64.pl b/crypto/rc4/asm/rc4-amd64.pl
index 35e426d561..9e0da8af99 100755
--- a/crypto/rc4/asm/rc4-amd64.pl
+++ b/crypto/rc4/asm/rc4-amd64.pl
@@ -30,7 +30,9 @@
 # RC4_CHAR. Kind of ironic, huh? As it's apparently impossible to
 # compose blended code, which would perform even within 30% marginal
 # on either AMD and Intel platforms, I implement both cases. See
-# rc4_skey.c for further details...
+# rc4_skey.c for further details... This applies to 0.9.8 and later.
+# In 0.9.7 context RC4_CHAR codepath is never engaged and ~70 bytes
+# of code remain redundant.
 
 $output=shift;
 
diff --git a/crypto/rc4/asm/rc4-ia64.S b/crypto/rc4/asm/rc4-ia64.S
index 4af7fba7b3..ae84af6729 100644
--- a/crypto/rc4/asm/rc4-ia64.S
+++ b/crypto/rc4/asm/rc4-ia64.S
@@ -18,7 +18,7 @@
 // to input and output streams. Secondly, less obvious, it's possible
 // to pull up some references to elements of the key schedule itself.
 // Fact is that such prior loads are not safe only for "degenerated"
-// key schedule, when all elements equal to the same value, which is
+// key schedule, when some elements equal to the same value, which is
 // never the case [key schedule setup routine makes sure it's not].
 // Furthermore. In order to compress loop body to the minimum, I chose
 // to deploy deposit instruction, which substitutes for the whole