From: H.J. Lu Date: Fri, 1 Apr 2016 22:08:48 +0000 (-0700) Subject: Remove Fast_Copy_Backward from Intel Core processors X-Git-Tag: glibc-2.24~428 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=27d3ce1467990f89126e228559dec8f84b96c60e;p=thirdparty%2Fglibc.git Remove Fast_Copy_Backward from Intel Core processors Intel Core i3, i5 and i7 processors have fast unaligned copy and copy backward is ignored. Remove Fast_Copy_Backward from Intel Core processors to avoid confusion. * sysdeps/x86/cpu-features.c (init_cpu_features): Don't set bit_arch_Fast_Copy_Backward for Intel Core proessors. --- diff --git a/ChangeLog b/ChangeLog index c181042349e..d22231b95d5 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2016-04-01 H.J. Lu + + * sysdeps/x86/cpu-features.c (init_cpu_features): Don't set + bit_arch_Fast_Copy_Backward for Intel Core proessors. + 2016-04-01 Adhemerval Zanella * string/strcspn.c (strcspn): Use PTR_ALIGN_DOWN. diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c index de75c79cf98..963b8459168 100644 --- a/sysdeps/x86/cpu-features.c +++ b/sysdeps/x86/cpu-features.c @@ -176,11 +176,8 @@ init_cpu_features (struct cpu_features *cpu_features) case 0x2c: case 0x2e: case 0x2f: - /* Rep string instructions, copy backward, unaligned loads + /* Rep string instructions, unaligned load, unaligned copy, and pminub are fast on Intel Core i3, i5 and i7. */ -#if index_arch_Fast_Rep_String != index_arch_Fast_Copy_Backward -# error index_arch_Fast_Rep_String != index_arch_Fast_Copy_Backward -#endif #if index_arch_Fast_Rep_String != index_arch_Fast_Unaligned_Load # error index_arch_Fast_Rep_String != index_arch_Fast_Unaligned_Load #endif @@ -192,7 +189,6 @@ init_cpu_features (struct cpu_features *cpu_features) #endif cpu_features->feature[index_arch_Fast_Rep_String] |= (bit_arch_Fast_Rep_String - | bit_arch_Fast_Copy_Backward | bit_arch_Fast_Unaligned_Load | bit_arch_Fast_Unaligned_Copy | bit_arch_Prefer_PMINUB_for_stringop);