Revert "Revert "X86: Use locked add rather than mfence""
This reverts commit 0da3b9117706760e8722029f407da6d0297cc943.
Fix a compilation failure that slipped in somehow.
Change-Id: Ide8681cdc921febb296ea47aa282cc195f154049
diff --git a/compiler/optimizing/code_generator_x86.h b/compiler/optimizing/code_generator_x86.h
index 7c292fa..ebbe486 100644
--- a/compiler/optimizing/code_generator_x86.h
+++ b/compiler/optimizing/code_generator_x86.h
@@ -17,6 +17,7 @@
#ifndef ART_COMPILER_OPTIMIZING_CODE_GENERATOR_X86_H_
#define ART_COMPILER_OPTIMIZING_CODE_GENERATOR_X86_H_
+#include "arch/x86/instruction_set_features_x86.h"
#include "code_generator.h"
#include "dex/compiler_enums.h"
#include "driver/compiler_options.h"
@@ -496,6 +497,19 @@
// artReadBarrierForRootSlow.
void GenerateReadBarrierForRootSlow(HInstruction* instruction, Location out, Location root);
+ // Ensure that prior stores complete to memory before subsequent loads.
+ // The locked add implementation will avoid serializing device memory, but will
+ // touch (but not change) the top of the stack.
+ // The 'non_temporal' parameter should be used to ensure ordering of non-temporal stores.
+ void MemoryFence(bool non_temporal = false) {
+ if (!non_temporal && isa_features_.PrefersLockedAddSynchronization()) {
+ assembler_.lock()->addl(Address(ESP, 0), Immediate(0));
+ } else {
+ assembler_.mfence();
+ }
+ }
+
+
private:
// Factored implementation of GenerateFieldLoadWithBakerReadBarrier
// and GenerateArrayLoadWithBakerReadBarrier.