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41 lines
1.6 KiB
41 lines
1.6 KiB
From 27d3ce1467990f89126e228559dec8f84b96c60e Mon Sep 17 00:00:00 2001 |
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From: "H.J. Lu" <hjl.tools@gmail.com> |
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Date: Fri, 1 Apr 2016 15:08:48 -0700 |
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Subject: [PATCH] Remove Fast_Copy_Backward from Intel Core processors |
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Intel Core i3, i5 and i7 processors have fast unaligned copy and |
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copy backward is ignored. Remove Fast_Copy_Backward from Intel Core |
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processors to avoid confusion. |
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* sysdeps/x86/cpu-features.c (init_cpu_features): Don't set |
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bit_arch_Fast_Copy_Backward for Intel Core proessors. |
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--- |
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ChangeLog | 5 +++++ |
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sysdeps/x86/cpu-features.c | 6 +----- |
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2 files changed, 6 insertions(+), 5 deletions(-) |
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diff -rup a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c |
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--- a/sysdeps/x86/cpu-features.c 2020-01-21 16:44:28.637555853 -0500 |
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+++ b/sysdeps/x86/cpu-features.c 2020-01-21 16:46:51.208756416 -0500 |
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@@ -116,11 +116,8 @@ init_cpu_features (struct cpu_features * |
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case 0x2c: |
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case 0x2e: |
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case 0x2f: |
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- /* Rep string instructions, copy backward, unaligned loads |
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+ /* Rep string instructions, unaligned load, unaligned copy, |
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and pminub are fast on Intel Core i3, i5 and i7. */ |
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-#if index_Fast_Rep_String != index_Fast_Copy_Backward |
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-# error index_Fast_Rep_String != index_Fast_Copy_Backward |
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-#endif |
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#if index_Fast_Rep_String != index_Fast_Unaligned_Load |
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# error index_Fast_Rep_String != index_Fast_Unaligned_Load |
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#endif |
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@@ -129,7 +126,6 @@ init_cpu_features (struct cpu_features * |
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#endif |
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cpu_features->feature[index_Fast_Rep_String] |
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|= (bit_Fast_Rep_String |
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- | bit_Fast_Copy_Backward |
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| bit_Fast_Unaligned_Load |
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| bit_Prefer_PMINUB_for_stringop); |
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break; |
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