From e7c6f40a65a8b103b6cc59dde0dfe8160b93275b Mon Sep 17 00:00:00 2001
From: "plind44@gmail.com"
 <plind44@gmail.com@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Fri, 9 May 2014 15:49:42 +0000
Subject: [PATCH] MIPS: Improve Array.shift() performance for small arrays.

Port r21203 (eaa92e4)

TEST=mjsunit/array-shift,mjsunit/array-shift2,mjsunit/array-shift3
BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/275883002

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21229 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/mips/code-stubs-mips.cc      | 10 ++++++++++
 src/mips/lithium-codegen-mips.cc |  9 +++++++++
 src/mips/lithium-mips.cc         |  8 ++++++++
 src/mips/lithium-mips.h          | 16 ++++++++++++++++
 4 files changed, 43 insertions(+)

diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index 486e4c2..a746d76 100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -306,6 +306,16 @@ void ElementsTransitionAndStoreStub::InitializeInterfaceDescriptor(
 }
 
 
+void ArrayShiftStub::InitializeInterfaceDescriptor(
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { a0 };
+  descriptor->register_param_count_ = 1;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ =
+      Builtins::c_function_address(Builtins::c_ArrayShift);
+}
+
+
 void BinaryOpICStub::InitializeInterfaceDescriptor(
     CodeStubInterfaceDescriptor* descriptor) {
   static Register registers[] = { a1, a0 };
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index 95ee3a6..b731baa 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -4442,6 +4442,15 @@ void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
 }
 
 
+void LCodeGen::DoArrayShift(LArrayShift* instr) {
+  ASSERT(ToRegister(instr->context()).is(cp));
+  ASSERT(ToRegister(instr->object()).is(a0));
+  ASSERT(ToRegister(instr->result()).is(v0));
+  ArrayShiftStub stub(isolate(), instr->hydrogen()->kind());
+  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
+}
+
+
 void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
   Register object = ToRegister(instr->object());
   Register temp = ToRegister(instr->temp());
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index e882655..97b91fa 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -2209,6 +2209,14 @@ LInstruction* LChunkBuilder::DoTransitionElementsKind(
 }
 
 
+LInstruction* LChunkBuilder::DoArrayShift(HArrayShift* instr) {
+  LOperand* object = UseFixed(instr->object(), a0);
+  LOperand* context = UseFixed(instr->context(), cp);
+  LArrayShift* result = new(zone()) LArrayShift(context, object);
+  return MarkAsCall(DefineFixed(result, v0), instr, CANNOT_DEOPTIMIZE_EAGERLY);
+}
+
+
 LInstruction* LChunkBuilder::DoTrapAllocationMemento(
     HTrapAllocationMemento* instr) {
   LOperand* object = UseRegister(instr->object());
diff --git a/src/mips/lithium-mips.h b/src/mips/lithium-mips.h
index 14ac0a4..8133c31 100644
--- a/src/mips/lithium-mips.h
+++ b/src/mips/lithium-mips.h
@@ -26,6 +26,7 @@ class LCodeGen;
   V(ArgumentsLength)                            \
   V(ArithmeticD)                                \
   V(ArithmeticT)                                \
+  V(ArrayShift)                                 \
   V(BitI)                                       \
   V(BoundsCheck)                                \
   V(Branch)                                     \
@@ -2236,6 +2237,21 @@ class LTransitionElementsKind V8_FINAL : public LTemplateInstruction<0, 2, 1> {
 };
 
 
+class LArrayShift V8_FINAL : public LTemplateInstruction<1, 2, 0> {
+ public:
+  LArrayShift(LOperand* context, LOperand* object) {
+    inputs_[0] = context;
+    inputs_[1] = object;
+  }
+
+  LOperand* context() const { return inputs_[0]; }
+  LOperand* object() const { return inputs_[1]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(ArrayShift, "array-shift")
+  DECLARE_HYDROGEN_ACCESSOR(ArrayShift)
+};
+
+
 class LTrapAllocationMemento V8_FINAL : public LTemplateInstruction<0, 1, 1> {
  public:
   LTrapAllocationMemento(LOperand* object,
-- 
2.7.4