[llvm] r309494 - [AArch64] Use 8 bytes as preferred function alignment on Cortex-A53.

[Florian Hahn via llvm-commits]

Author: fhahn
Date: Sat Jul 29 13:04:54 2017
New Revision: 309494

URL: http://llvm.org/viewvc/llvm-project?rev=309494&view=rev
Log:
[AArch64] Use 8 bytes as preferred function alignment on Cortex-A53.

Summary:
This change gives a 0.25% speedup on execution time, a 0.82% improvement
in benchmark scores and a 0.20% increase in binary size on a Cortex-A53.
These numbers are the geomean results on a wide range of benchmarks from
the test-suite and a range of proprietary suites.

Reviewers: t.p.northover, aadg, silviu.baranga, mcrosier, rengolin

Reviewed By: rengolin

Subscribers: grimar, davide, aemerson, rengolin, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D35568

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

Modified: llvm/trunk/lib/Target/AArch64/AArch64Subtarget.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64Subtarget.cpp?rev=309494&r1=309493&r2=309494&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64Subtarget.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64Subtarget.cpp Sat Jul 29 13:04:54 2017
@@ -130,7 +130,9 @@ void AArch64Subtarget::initializePropert
     MinVectorRegisterBitWidth = 128;
     break;
   case CortexA35: break;
-  case CortexA53: break;
+  case CortexA53:
+    PrefFunctionAlignment = 3;
+    break;
   case CortexA72:
     PrefFunctionAlignment = 4;
     break;

Modified: llvm/trunk/test/CodeGen/AArch64/preferred-function-alignment.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/preferred-function-alignment.ll?rev=309494&r1=309493&r2=309494&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/preferred-function-alignment.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/preferred-function-alignment.ll Sat Jul 29 13:04:54 2017
@@ -1,9 +1,9 @@
 ; 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=ALIGN2,CHECK %s
 ; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=cyclone < %s | FileCheck --check-prefixes=ALIGN2,CHECK %s
 ; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=falkor < %s | FileCheck --check-prefixes=ALIGN2,CHECK %s
 ; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=kryo < %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=thunderx < %s | FileCheck --check-prefixes=ALIGN3,CHECK %s
 ; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=thunderxt81 < %s | FileCheck --check-prefixes=ALIGN3,CHECK %s
 ; RUN: llc -mtriple=aarch64-unknown-linux -mcpu=thunderxt83 < %s | FileCheck --check-prefixes=ALIGN3,CHECK %s