[AArch64] Sets the preferred function alignment for Cortex-A53/A55.

Setting the preffered function alignment to 16 for Cortex A53/A55
improves performance in a wide range of benchmarks. This brings it
in line with the Cortex-A53/A55 tuning that is used in GCC
(gcc/config/aarch64/aarch64.c).

Differential Revision: https://reviews.llvm.org/D101636

Change-Id: I2ce47fe7ab5e3b54f49c89038d8da4e404742de2

diff --git a/llvm/lib/Target/AArch64/AArch64Subtarget.cpp b/llvm/lib/Target/AArch64/AArch64Subtarget.cpp
index 3451e8f..480600d 100644 (file)
--- a/llvm/lib/Target/AArch64/AArch64Subtarget.cpp
+++ b/llvm/lib/Target/AArch64/AArch64Subtarget.cpp
@@ -89,9 +89,8 @@ void AArch64Subtarget::initializeProperties() {
   case CortexA35:
     break;
   case CortexA53:
-    PrefFunctionLogAlignment = 3;
-    break;
   case CortexA55:
+    PrefFunctionLogAlignment = 4;
     break;
   case CortexA57:
     MaxInterleaveFactor = 4;

diff --git a/llvm/test/CodeGen/AArch64/preferred-function-alignment.ll b/llvm/test/CodeGen/AArch64/preferred-function-alignment.ll
index fb7b805..cba5116 100644 (file)
--- a/llvm/test/CodeGen/AArch64/preferred-function-alignment.ll
+++ b/llvm/test/CodeGen/AArch64/preferred-function-alignment.ll
@@ -1,6 +1,7 @@
 ; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=generic < %s | FileCheck --check-prefixes=ALIGN2,CHECK %s
 ; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=cortex-a35 < %s | FileCheck --check-prefixes=ALIGN2,CHECK %s
-; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=cortex-a53 < %s | FileCheck --check-prefixes=ALIGN3,CHECK %s
+; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=cortex-a53 < %s | FileCheck --check-prefixes=ALIGN4,CHECK %s
+; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=cortex-a55 < %s | FileCheck --check-prefixes=ALIGN4,CHECK %s
 ; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=cortex-a57 < %s | FileCheck --check-prefixes=ALIGN4,CHECK %s
 ; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=cortex-a65 < %s | FileCheck --check-prefixes=ALIGN3,CHECK %s
 ; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=cortex-a65ae < %s | FileCheck --check-prefixes=ALIGN3,CHECK %s