Clean up handling of global cell stores in the optimizing compiler.

Tell the register allocator the value is not overwritten.  Never use
temporary registers on ia32, avoid them on x64 and ARM.  Restore the
original copyright date on assembler.cc.

R=fschneider@chromium.org
BUG=v8:1870
TEST=

Review URL: http://codereview.chromium.org/8965038

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10280 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index 1ac152d6a7ec605d725dc8c5adfe4d8dbe853d89..643d0ebe606a422998d3c8fc4dee5986b5b2ebac 100644 (file)
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -1779,11 +1779,12 @@ LInstruction* LChunkBuilder::DoLoadGlobalGeneric(HLoadGlobalGeneric* instr) {
 
 
 LInstruction* LChunkBuilder::DoStoreGlobalCell(HStoreGlobalCell* instr) {
-  LOperand* temp = TempRegister();
-  LOperand* value = UseTempRegister(instr->value());
-  LInstruction* result = new LStoreGlobalCell(value, temp);
-  if (instr->RequiresHoleCheck()) result = AssignEnvironment(result);
-  return result;
+  LOperand* value = UseRegister(instr->value());
+  // Use a temp to check the value in the cell in the case where we perform
+  // a hole check.
+  return instr->RequiresHoleCheck()
+      ? AssignEnvironment(new LStoreGlobalCell(value, TempRegister()))
+      : new LStoreGlobalCell(value, NULL);
 }
 
 

diff --git a/src/arm/lithium-arm.h b/src/arm/lithium-arm.h
index 628c3d1a593a83007bf734f58a7c5eaba3cb9680..703666c4a15514a5f4d306617450c85272a50ddd 100644 (file)
--- a/src/arm/lithium-arm.h
+++ b/src/arm/lithium-arm.h
@@ -1242,6 +1242,8 @@ class LStoreGlobalCell: public LTemplateInstruction<0, 1, 1> {
 
   DECLARE_CONCRETE_INSTRUCTION(StoreGlobalCell, "store-global-cell")
   DECLARE_HYDROGEN_ACCESSOR(StoreGlobalCell)
+
+  LOperand* value() { return inputs_[0]; }
 };
 
 

diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index cdc464c32226e3ee2ebd40147b32c0ef953be8b7..4b68438300e32f8da20f84b9bb001ae7ba203c2b 100644 (file)
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -2262,27 +2262,26 @@ void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
 
 
 void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
-  Register value = ToRegister(instr->InputAt(0));
-  Register scratch = scratch0();
-  Register scratch2 = ToRegister(instr->TempAt(0));
+  Register value = ToRegister(instr->value());
+  Register cell = scratch0();
 
   // Load the cell.
-  __ mov(scratch, Operand(Handle<Object>(instr->hydrogen()->cell())));
+  __ mov(cell, Operand(instr->hydrogen()->cell()));
 
   // If the cell we are storing to contains the hole it could have
   // been deleted from the property dictionary. In that case, we need
   // to update the property details in the property dictionary to mark
   // it as no longer deleted.
   if (instr->hydrogen()->RequiresHoleCheck()) {
-    __ ldr(scratch2,
-           FieldMemOperand(scratch, JSGlobalPropertyCell::kValueOffset));
-    __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
-    __ cmp(scratch2, ip);
+    // We use a temp to check the payload (CompareRoot might clobber ip).
+    Register payload = ToRegister(instr->TempAt(0));
+    __ ldr(payload, FieldMemOperand(cell, JSGlobalPropertyCell::kValueOffset));
+    __ CompareRoot(payload, Heap::kTheHoleValueRootIndex);
     DeoptimizeIf(eq, instr->environment());
   }
 
   // Store the value.
-  __ str(value, FieldMemOperand(scratch, JSGlobalPropertyCell::kValueOffset));
+  __ str(value, FieldMemOperand(cell, JSGlobalPropertyCell::kValueOffset));
   // Cells are always rescanned, so no write barrier here.
 }
 

diff --git a/src/assembler.cc b/src/assembler.cc
index b66f448407c8c1982bfc1336f32eb9c756f3e39e..2de7b92f5ef2f0aa25375a5fa284e71b0155d3ad 100644 (file)
--- a/src/assembler.cc
+++ b/src/assembler.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 Sun Microsystems Inc.
+// Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without

diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 788348104110b5bfec90e9ed627c194171fe03b9..ab3850276891022b6823cb0f56a14c172f003898 100644 (file)
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -2124,26 +2124,20 @@ void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
 
 
 void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
-  Register object = ToRegister(instr->TempAt(0));
-  Register address = ToRegister(instr->TempAt(1));
-  Register value = ToRegister(instr->InputAt(0));
-  ASSERT(!value.is(object));
-  Handle<JSGlobalPropertyCell> cell_handle(instr->hydrogen()->cell());
-
-  int offset = JSGlobalPropertyCell::kValueOffset;
-  __ mov(object, Immediate(cell_handle));
+  Register value = ToRegister(instr->value());
+  Handle<JSGlobalPropertyCell> cell_handle = instr->hydrogen()->cell();
 
   // If the cell we are storing to contains the hole it could have
   // been deleted from the property dictionary. In that case, we need
   // to update the property details in the property dictionary to mark
   // it as no longer deleted. We deoptimize in that case.
   if (instr->hydrogen()->RequiresHoleCheck()) {
-    __ cmp(FieldOperand(object, offset), factory()->the_hole_value());
+    __ cmp(Operand::Cell(cell_handle), factory()->the_hole_value());
     DeoptimizeIf(equal, instr->environment());
   }
 
   // Store the value.
-  __ mov(FieldOperand(object, offset), value);
+  __ mov(Operand::Cell(cell_handle), value);
   // Cells are always rescanned, so no write barrier here.
 }
 

diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index f364439f10921d5ee47dbbd47771aa4c53bf10c5..c50378514a6bf1d25548be68c771a08c0d6e1d81 100644 (file)
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -1856,9 +1856,7 @@ LInstruction* LChunkBuilder::DoLoadGlobalGeneric(HLoadGlobalGeneric* instr) {
 
 LInstruction* LChunkBuilder::DoStoreGlobalCell(HStoreGlobalCell* instr) {
   LStoreGlobalCell* result =
-      new(zone()) LStoreGlobalCell(UseTempRegister(instr->value()),
-                           TempRegister(),
-                           TempRegister());
+      new(zone()) LStoreGlobalCell(UseRegister(instr->value()));
   return instr->RequiresHoleCheck() ? AssignEnvironment(result) : result;
 }
 

diff --git a/src/ia32/lithium-ia32.h b/src/ia32/lithium-ia32.h
index 7e126ff03c4c24ee56fc561cef9a3e3c2fc60d8e..cc3762d7ab42e0dbda448370ecd5b5da321c8f84 100644 (file)
--- a/src/ia32/lithium-ia32.h
+++ b/src/ia32/lithium-ia32.h
@@ -1269,16 +1269,16 @@ class LLoadGlobalGeneric: public LTemplateInstruction<1, 2, 0> {
 };
 
 
-class LStoreGlobalCell: public LTemplateInstruction<0, 1, 2> {
+class LStoreGlobalCell: public LTemplateInstruction<0, 1, 0> {
  public:
-  explicit LStoreGlobalCell(LOperand* value, LOperand* temp1, LOperand* temp2) {
+  explicit LStoreGlobalCell(LOperand* value) {
     inputs_[0] = value;
-    temps_[0] = temp1;
-    temps_[1] = temp2;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(StoreGlobalCell, "store-global-cell")
   DECLARE_HYDROGEN_ACCESSOR(StoreGlobalCell)
+
+  LOperand* value() { return inputs_[0]; }
 };
 
 

diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index a96d140d49b967f9b62fa3d75fb31f2ffaf75fe7..70f5874b5c50e33ea02353563d09227311328eda 100644 (file)
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -2028,25 +2028,27 @@ void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
 
 
 void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
-  Register object = ToRegister(instr->TempAt(0));
-  Register address = ToRegister(instr->TempAt(1));
-  Register value = ToRegister(instr->InputAt(0));
-  ASSERT(!value.is(object));
-  Handle<JSGlobalPropertyCell> cell_handle(instr->hydrogen()->cell());
-
-  __ movq(address, cell_handle, RelocInfo::GLOBAL_PROPERTY_CELL);
+  Register value = ToRegister(instr->value());
+  Handle<JSGlobalPropertyCell> cell_handle = instr->hydrogen()->cell();
 
   // If the cell we are storing to contains the hole it could have
   // been deleted from the property dictionary. In that case, we need
   // to update the property details in the property dictionary to mark
   // it as no longer deleted. We deoptimize in that case.
   if (instr->hydrogen()->RequiresHoleCheck()) {
-    __ CompareRoot(Operand(address, 0), Heap::kTheHoleValueRootIndex);
+    // We have a temp because CompareRoot might clobber kScratchRegister.
+    Register cell = ToRegister(instr->TempAt(0));
+    ASSERT(!value.is(cell));
+    __ movq(cell, cell_handle, RelocInfo::GLOBAL_PROPERTY_CELL);
+    __ CompareRoot(Operand(cell, 0), Heap::kTheHoleValueRootIndex);
     DeoptimizeIf(equal, instr->environment());
+    // Store the value.
+    __ movq(Operand(cell, 0), value);
+  } else {
+    // Store the value.
+    __ movq(kScratchRegister, cell_handle, RelocInfo::GLOBAL_PROPERTY_CELL);
+    __ movq(Operand(kScratchRegister, 0), value);
   }
-
-  // Store the value.
-  __ movq(Operand(address, 0), value);
   // Cells are always rescanned, so no write barrier here.
 }
 

diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index 7fa8a3999c91f797c05b4b7778d283f931f099dd..ac4d5f5d3e6ffae92863dc35d3877a663cfd1585 100644 (file)
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -1768,11 +1768,12 @@ LInstruction* LChunkBuilder::DoLoadGlobalGeneric(HLoadGlobalGeneric* instr) {
 
 
 LInstruction* LChunkBuilder::DoStoreGlobalCell(HStoreGlobalCell* instr) {
-  LStoreGlobalCell* result =
-      new LStoreGlobalCell(UseTempRegister(instr->value()),
-                           TempRegister(),
-                           TempRegister());
-  return instr->RequiresHoleCheck() ? AssignEnvironment(result) : result;
+  LOperand* value = UseRegister(instr->value());
+  // Use a temp to avoid reloading the cell value address in the case where
+  // we perform a hole check.
+  return instr->RequiresHoleCheck()
+      ? AssignEnvironment(new LStoreGlobalCell(value, TempRegister()))
+      : new LStoreGlobalCell(value, NULL);
 }
 
 

diff --git a/src/x64/lithium-x64.h b/src/x64/lithium-x64.h
index 280d2358c4c243942e42dbf65bc9dcae79353358..c6fcfeb81ea867f8d9a82b0888ff8cc429996bd0 100644 (file)
--- a/src/x64/lithium-x64.h
+++ b/src/x64/lithium-x64.h
@@ -1231,16 +1231,17 @@ class LLoadGlobalGeneric: public LTemplateInstruction<1, 1, 0> {
 };
 
 
-class LStoreGlobalCell: public LTemplateInstruction<0, 1, 2> {
+class LStoreGlobalCell: public LTemplateInstruction<0, 1, 1> {
  public:
-  explicit LStoreGlobalCell(LOperand* value, LOperand* temp1, LOperand* temp2) {
+  explicit LStoreGlobalCell(LOperand* value, LOperand* temp) {
     inputs_[0] = value;
-    temps_[0] = temp1;
-    temps_[1] = temp2;
+    temps_[0] = temp;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(StoreGlobalCell, "store-global-cell")
   DECLARE_HYDROGEN_ACCESSOR(StoreGlobalCell)
+
+  LOperand* value() { return inputs_[0]; }
 };