From 27d3ce1467990f89126e228559dec8f84b96c60e Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Fri, 1 Apr 2016 15:08:48 -0700 Subject: [PATCH] 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. --- ChangeLog | 5 +++++ sysdeps/x86/cpu-features.c | 6 +----- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/ChangeLog b/ChangeLog index c181042349..d22231b95d 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 de75c79cf9..963b845916 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);