s390x assembler pack: tune-up and support for new z196 hardware.
diff --git a/crypto/modes/asm/ghash-s390x.pl b/crypto/modes/asm/ghash-s390x.pl
index 16ad034..48cb08d 100644
--- a/crypto/modes/asm/ghash-s390x.pl
+++ b/crypto/modes/asm/ghash-s390x.pl
@@ -28,6 +28,15 @@
# remains z/Architecture specific. On z990 it was measured to perform
# 2.8x better than 32-bit code generated by gcc 4.3.
+# March 2011.
+#
+# Support for hardware KIMD-GHASH is verified to produce correct
+# result and therefore is engaged. On z196 it was measured to process
+# 8KB buffer ~7 faster than software implementation. It's not as
+# impressive for smaller buffer sizes and for smallest 16-bytes buffer
+# it's actually almost 2 times slower. Which is the reason why
+# KIMD-GHASH is not used in gcm_gmult_4bit.
+
$flavour = shift;
if ($flavour =~ /3[12]/) {
@@ -41,7 +50,7 @@
while (($output=shift) && ($output!~/^\w[\w\-]*\.\w+$/)) {}
open STDOUT,">$output";
-$softonly=1; # disable hardware support for now
+$softonly=0;
$Zhi="%r0";
$Zlo="%r1";
@@ -70,7 +79,7 @@
.align 32
gcm_gmult_4bit:
___
-$code.=<<___ if(!$softonly);
+$code.=<<___ if(!$softonly && 0); # hardware is slow for single block...
larl %r1,OPENSSL_s390xcap_P
lg %r0,0(%r1)
tmhl %r0,0x4000 # check for message-security-assist
