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authorH.J. Lu <hjl.tools@gmail.com>2016-04-01 15:08:48 -0700
committerH.J. Lu <hjl.tools@gmail.com>2016-04-01 15:09:14 -0700
commit27d3ce1467990f89126e228559dec8f84b96c60e (patch)
tree2d67df078f6e7ad4fdb0f7492426922ff762b9ee /sysdeps/x86
parent2e51bc3813ca3fe72fd197d08d79496e46669f43 (diff)
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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.
Diffstat (limited to 'sysdeps/x86')
-rw-r--r--sysdeps/x86/cpu-features.c6
1 files changed, 1 insertions, 5 deletions
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);