x86-64 Baker's read barrier fast path implementation.
Introduce an x86-64 fast path implementation in Optimizing
for Baker's read barriers (for both heap reference loads and
GC root loads). The marking phase of the read barrier is
performed by a slow path, invoking the runtime entry point
artReadBarrierMark.
Other read barrier algorithms continue to use the original
slow path based implementation, which has been renamed as
GenerateReadBarrierSlow/GenerateReadBarrierForRootSlow.
Bug: 12687968
Change-Id: I9329293ddca7f9bcb512132bde6675aa202b98b2
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index 7351fed..dda9ea2 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -213,11 +213,44 @@
void GenerateDivRemWithAnyConstant(HBinaryOperation* instruction);
void GenerateDivRemIntegral(HBinaryOperation* instruction);
void HandleShift(HBinaryOperation* operation);
- void GenerateMemoryBarrier(MemBarrierKind kind);
+
void HandleFieldSet(HInstruction* instruction,
const FieldInfo& field_info,
bool value_can_be_null);
void HandleFieldGet(HInstruction* instruction, const FieldInfo& field_info);
+
+ // Generate a heap reference load using one register `out`:
+ //
+ // out <- *(out + offset)
+ //
+ // while honoring heap poisoning and/or read barriers (if any).
+ // Register `temp` is used when generating a read barrier.
+ void GenerateReferenceLoadOneRegister(HInstruction* instruction,
+ Location out,
+ uint32_t offset,
+ Location temp);
+ // Generate a heap reference load using two different registers
+ // `out` and `obj`:
+ //
+ // out <- *(obj + offset)
+ //
+ // while honoring heap poisoning and/or read barriers (if any).
+ // Register `temp` is used when generating a Baker's read barrier.
+ void GenerateReferenceLoadTwoRegisters(HInstruction* instruction,
+ Location out,
+ Location obj,
+ uint32_t offset,
+ Location temp);
+ // Generate a GC root reference load:
+ //
+ // root <- *(obj + offset)
+ //
+ // while honoring read barriers (if any).
+ void GenerateGcRootFieldLoad(HInstruction* instruction,
+ Location root,
+ CpuRegister obj,
+ uint32_t offset);
+
void GenerateImplicitNullCheck(HNullCheck* instruction);
void GenerateExplicitNullCheck(HNullCheck* instruction);
void PushOntoFPStack(Location source, uint32_t temp_offset,
@@ -324,6 +357,8 @@
CpuRegister value,
bool value_can_be_null);
+ void GenerateMemoryBarrier(MemBarrierKind kind);
+
// Helper method to move a value between two locations.
void Move(Location destination, Location source);
@@ -356,7 +391,26 @@
return isa_features_;
}
- // Generate a read barrier for a heap reference within `instruction`.
+ // Fast path implementation of ReadBarrier::Barrier for a heap
+ // reference field load when Baker's read barriers are used.
+ void GenerateFieldLoadWithBakerReadBarrier(HInstruction* instruction,
+ Location out,
+ CpuRegister obj,
+ uint32_t offset,
+ Location temp,
+ bool needs_null_check);
+ // Fast path implementation of ReadBarrier::Barrier for a heap
+ // reference array load when Baker's read barriers are used.
+ void GenerateArrayLoadWithBakerReadBarrier(HInstruction* instruction,
+ Location out,
+ CpuRegister obj,
+ uint32_t data_offset,
+ Location index,
+ Location temp,
+ bool needs_null_check);
+
+ // Generate a read barrier for a heap reference within `instruction`
+ // using a slow path.
//
// A read barrier for an object reference read from the heap is
// implemented as a call to the artReadBarrierSlow runtime entry
@@ -373,23 +427,25 @@
// When `index` provided (i.e., when it is different from
// Location::NoLocation()), the offset value passed to
// artReadBarrierSlow is adjusted to take `index` into account.
- void GenerateReadBarrier(HInstruction* instruction,
- Location out,
- Location ref,
- Location obj,
- uint32_t offset,
- Location index = Location::NoLocation());
+ void GenerateReadBarrierSlow(HInstruction* instruction,
+ Location out,
+ Location ref,
+ Location obj,
+ uint32_t offset,
+ Location index = Location::NoLocation());
- // If read barriers are enabled, generate a read barrier for a heap reference.
- // If heap poisoning is enabled, also unpoison the reference in `out`.
- void MaybeGenerateReadBarrier(HInstruction* instruction,
- Location out,
- Location ref,
- Location obj,
- uint32_t offset,
- Location index = Location::NoLocation());
+ // If read barriers are enabled, generate a read barrier for a heap
+ // reference using a slow path. If heap poisoning is enabled, also
+ // unpoison the reference in `out`.
+ void MaybeGenerateReadBarrierSlow(HInstruction* instruction,
+ Location out,
+ Location ref,
+ Location obj,
+ uint32_t offset,
+ Location index = Location::NoLocation());
- // Generate a read barrier for a GC root within `instruction`.
+ // Generate a read barrier for a GC root within `instruction` using
+ // a slow path.
//
// A read barrier for an object reference GC root is implemented as
// a call to the artReadBarrierForRootSlow runtime entry point,
@@ -399,7 +455,7 @@
//
// The `out` location contains the value returned by
// artReadBarrierForRootSlow.
- void GenerateReadBarrierForRoot(HInstruction* instruction, Location out, Location root);
+ void GenerateReadBarrierForRootSlow(HInstruction* instruction, Location out, Location root);
int ConstantAreaStart() const {
return constant_area_start_;
@@ -424,6 +480,15 @@
HInstruction* instruction);
private:
+ // Factored implementation of GenerateFieldLoadWithBakerReadBarrier
+ // and GenerateArrayLoadWithBakerReadBarrier.
+ void GenerateReferenceLoadWithBakerReadBarrier(HInstruction* instruction,
+ Location ref,
+ CpuRegister obj,
+ const Address& src,
+ Location temp,
+ bool needs_null_check);
+
struct PcRelativeDexCacheAccessInfo {
PcRelativeDexCacheAccessInfo(const DexFile& dex_file, uint32_t element_off)
: target_dex_file(dex_file), element_offset(element_off), label() { }