commit 579885a26d761f5ba9550f2a1cd7f0f598c2e1e3
author Serban Constantinescu <serban.constantinescu@arm.com> Sun Feb 22 20:51:33 2015 +0000
committer Serban Constantinescu <serban.constantinescu@arm.com> Mon Mar 02 14:16:56 2015 +0000
tree 58d144157b7a24bbdf7f8892631a15abeefa2c9f
parent 2eb5168bd9e43b80452eaee5be32c063e124886e

Opt Compiler: ARM64: Enable explicit memory barriers over acquire/release

Implement remaining explicit memory barrier code paths and temporarily
enable the use of explicit memory barriers for testing.

This CL also enables the use of instruction set features in the ARM64
backend. kUseAcquireRelease has been replaced with PreferAcquireRelease(),
which for now is statically set to false (prefer explicit memory barriers).

Please note that we still prefer acquire-release for the ARM64 Optimizing
Compiler, but we would like to exercise the explicit memory barrier code
path too.

Change-Id: I84e047ecd43b6fbefc5b82cf532e3f5c59076458
Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>

compiler/optimizing/code_generator_arm64.h

diff --git a/compiler/optimizing/code_generator_arm64.h b/compiler/optimizing/code_generator_arm64.h
index afb7fc3..48961d6 100644
--- a/compiler/optimizing/code_generator_arm64.h
+++ b/compiler/optimizing/code_generator_arm64.h
@@ -32,10 +32,6 @@
 
 class CodeGeneratorARM64;
 
-// TODO: Tune the use of Load-Acquire, Store-Release vs Data Memory Barriers.
-// For now we prefer the use of load-acquire, store-release over explicit memory barriers.
-static constexpr bool kUseAcquireRelease = true;
-
 // Use a local definition to prevent copying mistakes.
 static constexpr size_t kArm64WordSize = kArm64PointerSize;
 
@@ -195,7 +191,9 @@
 
 class CodeGeneratorARM64 : public CodeGenerator {
  public:
-  CodeGeneratorARM64(HGraph* graph, const CompilerOptions& compiler_options);
+  CodeGeneratorARM64(HGraph* graph,
+                     const Arm64InstructionSetFeatures& isa_features,
+                     const CompilerOptions& compiler_options);
   virtual ~CodeGeneratorARM64() {}
 
   void GenerateFrameEntry() OVERRIDE;
@@ -273,6 +271,10 @@
     return InstructionSet::kArm64;
   }
 
+  const Arm64InstructionSetFeatures& GetInstructionSetFeatures() const {
+    return isa_features_;
+  }
+
   void Initialize() OVERRIDE {
     HGraph* graph = GetGraph();
     int length = graph->GetBlocks().Size();
@@ -317,6 +319,7 @@
   InstructionCodeGeneratorARM64 instruction_visitor_;
   ParallelMoveResolverARM64 move_resolver_;
   Arm64Assembler assembler_;
+  const Arm64InstructionSetFeatures& isa_features_;
 
   DISALLOW_COPY_AND_ASSIGN(CodeGeneratorARM64);
 };