From 2312c8abdf4ee6f2dc9350bcfffdfa8802bca0b2 Mon Sep 17 00:00:00 2001
From: "weiliang.lin@intel.com"
 <weiliang.lin@intel.com@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Wed, 28 May 2014 08:16:11 +0000
Subject: [PATCH] X87: Avoid HeapObject check in HStoreNamedField.

port r21509 (78a54b0)

Original commit message:
This way an HStoreNamedField instruction can never deoptimize
itself, which is another important step towards a working
store elimination.

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/306483013

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21547 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/x87/lithium-codegen-x87.cc | 31 ++++++-------------------------
 src/x87/lithium-x87.cc         | 11 +----------
 src/x87/macro-assembler-x87.cc |  5 +++++
 3 files changed, 12 insertions(+), 35 deletions(-)

diff --git a/src/x87/lithium-codegen-x87.cc b/src/x87/lithium-codegen-x87.cc
index 60fe7254e9..975226bdaa 100644
--- a/src/x87/lithium-codegen-x87.cc
+++ b/src/x87/lithium-codegen-x87.cc
@@ -3888,30 +3888,11 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
   }
 
   Register object = ToRegister(instr->object());
-  SmiCheck check_needed =
-      instr->hydrogen()->value()->IsHeapObject()
-          ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
-
-  ASSERT(!(representation.IsSmi() &&
-           instr->value()->IsConstantOperand() &&
-           !IsSmi(LConstantOperand::cast(instr->value()))));
-  if (representation.IsHeapObject()) {
-    if (instr->value()->IsConstantOperand()) {
-      LConstantOperand* operand_value = LConstantOperand::cast(instr->value());
-      if (chunk_->LookupConstant(operand_value)->HasSmiValue()) {
-        DeoptimizeIf(no_condition, instr->environment());
-      }
-    } else {
-      if (!instr->hydrogen()->value()->type().IsHeapObject()) {
-        Register value = ToRegister(instr->value());
-        __ test(value, Immediate(kSmiTagMask));
-        DeoptimizeIf(zero, instr->environment());
-
-        // We know now that value is not a smi, so we can omit the check below.
-        check_needed = OMIT_SMI_CHECK;
-      }
-    }
-  } else if (representation.IsDouble()) {
+  __ AssertNotSmi(object);
+  ASSERT(!representation.IsSmi() ||
+         !instr->value()->IsConstantOperand() ||
+         IsSmi(LConstantOperand::cast(instr->value())));
+  if (representation.IsDouble()) {
     ASSERT(access.IsInobject());
     ASSERT(!instr->hydrogen()->has_transition());
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
@@ -3976,7 +3957,7 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
                         value,
                         temp,
                         EMIT_REMEMBERED_SET,
-                        check_needed);
+                        instr->hydrogen()->SmiCheckForWriteBarrier());
   }
 }
 
diff --git a/src/x87/lithium-x87.cc b/src/x87/lithium-x87.cc
index 715c936227..9bb649c1ff 100644
--- a/src/x87/lithium-x87.cc
+++ b/src/x87/lithium-x87.cc
@@ -2379,16 +2379,7 @@ LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
   // We need a temporary register for write barrier of the map field.
   LOperand* temp_map = needs_write_barrier_for_map ? TempRegister() : NULL;
 
-  LInstruction* result =
-      new(zone()) LStoreNamedField(obj, val, temp, temp_map);
-  if (!instr->access().IsExternalMemory() &&
-      instr->field_representation().IsHeapObject() &&
-      (val->IsConstantOperand()
-       ? HConstant::cast(instr->value())->HasSmiValue()
-       : !instr->value()->type().IsHeapObject())) {
-    result = AssignEnvironment(result);
-  }
-  return result;
+  return new(zone()) LStoreNamedField(obj, val, temp, temp_map);
 }
 
 
diff --git a/src/x87/macro-assembler-x87.cc b/src/x87/macro-assembler-x87.cc
index 7baa659d01..8d8876f1dd 100644
--- a/src/x87/macro-assembler-x87.cc
+++ b/src/x87/macro-assembler-x87.cc
@@ -55,6 +55,11 @@ void MacroAssembler::Store(Register src, const Operand& dst, Representation r) {
   } else if (r.IsInteger16() || r.IsUInteger16()) {
     mov_w(dst, src);
   } else {
+    if (r.IsHeapObject()) {
+      AssertNotSmi(src);
+    } else if (r.IsSmi()) {
+      AssertSmi(src);
+    }
     mov(dst, src);
   }
 }