[AArch64] Disable useAA for Cortex-A57.

Using AA during CodeGen is very useful for in-order cores. It is less useful for ooo cores. Also I find
enabling useAA for Cortex-A57 may generate worse code for some test cases. If useAA in codegen is improved
and benefical for ooo cores, we can enable it again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222333 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/AArch64/AArch64Subtarget.h b/lib/Target/AArch64/AArch64Subtarget.h
index 06bd3698c6a77f9280c2c9b685b6679b862d1e1e..e2740f137c26a203e720883e66872ef7fcb66674 100644 (file)
--- a/lib/Target/AArch64/AArch64Subtarget.h
+++ b/lib/Target/AArch64/AArch64Subtarget.h
@@ -115,7 +115,7 @@ public:
   bool isCortexA57() const { return CPUString == "cortex-a57"; }
   bool isCortexA53() const { return CPUString == "cortex-a53"; }
 
-  bool useAA() const override { return isCortexA53() || isCortexA57(); }
+  bool useAA() const override { return isCortexA53(); }
 
   /// getMaxInlineSizeThreshold - Returns the maximum memset / memcpy size
   /// that still makes it profitable to inline the call.