[llvm] 36a44df - [AArch64] Sets the preferred function alignment for Cortex-A53/A55.

[Stelios Ioannou via llvm-commits]

Author: Stelios Ioannou
Date: 2021-05-03T00:00:10+01:00
New Revision: 36a44dfd95d88fc13ce45b8d202ab05ff7641d23

URL: https://github.com/llvm/llvm-project/commit/36a44dfd95d88fc13ce45b8d202ab05ff7641d23
DIFF: https://github.com/llvm/llvm-project/commit/36a44dfd95d88fc13ce45b8d202ab05ff7641d23.diff

LOG: [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

Added: 
    

Modified: 
    llvm/lib/Target/AArch64/AArch64Subtarget.cpp
    llvm/test/CodeGen/AArch64/preferred-function-alignment.ll

Removed: 
    


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diff  --git a/llvm/lib/Target/AArch64/AArch64Subtarget.cpp b/llvm/lib/Target/AArch64/AArch64Subtarget.cpp
index 3451e8fc66496..480600dcd9321 100644
--- 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 fb7b805e4882c..cba5116b41d60 100644
--- 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