From: Liubov Dmitrieva <liubov.dmitrieva@intel.com>
Date: Fri, 14 Jun 2013 18:46:15 +0000 (+0200)
Subject: Set fast unaligned load flag for new Intel microarchitecture
X-Git-Tag: glibc-2.18~125
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d086fc7ba0d4b58c9db901780cb8adf415e1f2b5;p=thirdparty%2Fglibc.git

Set fast unaligned load flag for new Intel microarchitecture

I have small patch for new Intel Silvermont machines.

http://newsroom.intel.com/community/intel_newsroom/blog/2013/05/06/intel-launches-low-power-high-performance-silvermont-microarchitecture

I checked this on my machine and see that strcpy, ... unaligned
versions are faster than ssse3 versions.
---

diff --git a/ChangeLog b/ChangeLog
index 77ac80380c0..86d98f7274a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-06-14  Liubov Dmitrieva  <liubov.dmitrieva@intel.com>
+
+	* sysdeps/x86_64/multiarch/init-arch.c (__init_cpu_features):
+	Set bit_Fast_Unaligned_Load for Intel Silvermont architecture.
+
 2013-06-14  Siddhesh Poyarekar  <siddhesh@redhat.com>
 	    H.J. Lu  <hjl.tools@gmail.com>
 
diff --git a/sysdeps/x86_64/multiarch/init-arch.c b/sysdeps/x86_64/multiarch/init-arch.c
index 7daaf46099a..9524aeea18a 100644
--- a/sysdeps/x86_64/multiarch/init-arch.c
+++ b/sysdeps/x86_64/multiarch/init-arch.c
@@ -78,6 +78,13 @@ __init_cpu_features (void)
 	      __cpu_features.feature[index_Slow_BSF] |= bit_Slow_BSF;
 	      break;
 
+	    case 0x37:
+	      /* Unaligned load versions are faster than SSSE3
+		 on Silvermont.  */
+	      __cpu_features.feature[index_Fast_Unaligned_Load]
+		|= bit_Fast_Unaligned_Load;
+	      break;
+
 	    default:
 	      /* Unknown family 0x06 processors.  Assuming this is one
 		 of Core i3/i5/i7 processors if AVX is available.  */