commit 6c020ea4ffbba2b403a5e14f937047646a54368f
author Evan Cheng <evan.cheng@apple.com> Thu Apr 01 05:58:17 2010 +0000
committer Evan Cheng <evan.cheng@apple.com> Thu Apr 01 05:58:17 2010 +0000
tree 19a56b30f819109548c3d601bbf07e3a9c0a4f28
parent 453b3bdebbcd34b1f45988a6e7c8f77c7fcec67e

Nehalem unaligned memory access is fast.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100089 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86Subtarget.cpp

diff --git a/lib/Target/X86/X86Subtarget.cpp b/lib/Target/X86/X86Subtarget.cpp
index cd56816..8a0cde4 100644
--- a/lib/Target/X86/X86Subtarget.cpp
+++ b/lib/Target/X86/X86Subtarget.cpp
@@ -266,6 +266,9 @@
     unsigned Model  = 0;
     DetectFamilyModel(EAX, Family, Model);
     IsBTMemSlow = IsAMD || (Family == 6 && Model >= 13);
+    // If it's Nehalem, unaligned memory access is fast.
+    if (Family == 15 && Model == 26)
+      IsUAMemFast = true;
 
     GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
     HasX86_64 = (EDX >> 29) & 0x1;
@@ -286,6 +289,7 @@
   , HasFMA3(false)
   , HasFMA4(false)
   , IsBTMemSlow(false)
+  , IsUAMemFast(false)
   , HasVectorUAMem(false)
   , DarwinVers(0)
   , stackAlignment(8)