commit 37de2b5c1e370b493932552556940eb89922b027
author Andy Polyakov <appro@openssl.org> Wed Oct 09 11:08:52 2013 +0200
committer Andy Polyakov <appro@openssl.org> Wed Oct 09 11:08:52 2013 +0200
tree 180b9384cdf6c70b106db49a6e77e8f472a87979
parent 2d752737c53d0cf4953c11551d6d2a9df3655329

bn/bn_exp.c: prefer MULX/AD*X over AVX2.

crypto/bn/bn_exp.c

diff --git a/crypto/bn/bn_exp.c b/crypto/bn/bn_exp.c
index cfbaf2b..6e3a726 100644
--- a/crypto/bn/bn_exp.c
+++ b/crypto/bn/bn_exp.c
@@ -691,7 +691,8 @@
 	 * RSAZ exponentiation. For further information see
 	 * crypto/bn/rsaz_exp.c and accompanying assembly modules.
 	 */
-	if ((16 == a->top) && (16 == p->top) && (BN_num_bits(m) == 1024)
+	if (((OPENSSL_ia32cap_P[2]&0x80100) != 0x80100) /* check for MULX/AD*X */
+	    && (16 == a->top) && (16 == p->top) && (BN_num_bits(m) == 1024)
 	    && rsaz_avx2_eligible())
 	    	{
 		if (NULL == bn_wexpand(rr, 16)) goto err;