Implement type recording for ToBoolean on x64.

Handle oddballs on ia32 via root indices, similar to other platforms. Added a
special case for Smi types on ia32 to make lithium code generation on both Intel
platforms more similar.
Review URL: http://codereview.chromium.org/7544012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8767 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/code-stubs.h

@@ -955,7 +955,7 @@ class ToBooleanStub: public CodeStub {
 
   void CheckOddball(MacroAssembler* masm,
                     Type type,
-                    Handle<Object> value,
+                    Heap::RootListIndex value,
                     bool result,
                     Label* patch);
   void GenerateTypeTransition(MacroAssembler* masm);

src/ia32/code-stubs-ia32.cc

@@ -249,14 +249,14 @@ void ToBooleanStub::Generate(MacroAssembler* masm) {
   }
 
   // undefined -> false
-  CheckOddball(masm, UNDEFINED, factory->undefined_value(), false, &patch);
+  CheckOddball(masm, UNDEFINED, Heap::kUndefinedValueRootIndex, false, &patch);
 
   // Boolean -> its value
-  CheckOddball(masm, BOOLEAN, factory->false_value(), false, &patch);
-  CheckOddball(masm, BOOLEAN, factory->true_value(), true, &patch);
+  CheckOddball(masm, BOOLEAN, Heap::kFalseValueRootIndex, false, &patch);
+  CheckOddball(masm, BOOLEAN, Heap::kTrueValueRootIndex, true, &patch);
 
-  // 'null' -> false.
-  CheckOddball(masm, NULL_TYPE, factory->null_value(), false, &patch);
+  // 'null' -> false.!!!
+  CheckOddball(masm, NULL_TYPE, Heap::kNullValueRootIndex, false, &patch);
 
   if (types_.Contains(SMI)) {
     // Smis: 0 -> false, all other -> true
@@ -351,14 +351,14 @@ void ToBooleanStub::Generate(MacroAssembler* masm) {
 
 void ToBooleanStub::CheckOddball(MacroAssembler* masm,
                                  Type type,
-                                 Handle<Object> value,
+                                 Heap::RootListIndex value,
                                  bool result,
                                  Label* patch) {
   const Register argument = eax;
   if (types_.Contains(type)) {
     // If we see an expected oddball, return its ToBoolean value tos_.
     Label different_value;
-    __ cmp(argument, value);
+    __ CompareRoot(argument, value);
     __ j(not_equal, &different_value, Label::kNear);
     __ Set(tos_, Immediate(result ? 1 : 0));
     __ ret(1 * kPointerSize);
@@ -366,7 +366,7 @@ void ToBooleanStub::CheckOddball(MacroAssembler* masm,
   } else if (types_.Contains(INTERNAL_OBJECT)) {
     // If we see an unexpected oddball and handle internal objects, we must
     // patch because the code for internal objects doesn't handle it explictly.
-    __ cmp(argument, value);
+    __ CompareRoot(argument, value);
     __ j(equal, patch);
   }
 }

src/ia32/lithium-codegen-ia32.cc

@@ -1393,9 +1393,13 @@ void LCodeGen::DoBranch(LBranch* instr) {
   } else {
     ASSERT(r.IsTagged());
     Register reg = ToRegister(instr->InputAt(0));
-    if (instr->hydrogen()->value()->type().IsBoolean()) {
+    HType type = instr->hydrogen()->value()->type();
+    if (type.IsBoolean()) {
       __ cmp(reg, factory()->true_value());
       EmitBranch(true_block, false_block, equal);
+    } else if (type.IsSmi()) {
+      __ test(reg, Operand(reg));
+      EmitBranch(true_block, false_block, not_equal);
     } else {
       Label* true_label = chunk_->GetAssemblyLabel(true_block);
       Label* false_label = chunk_->GetAssemblyLabel(false_block);

src/ia32/macro-assembler-ia32.cc

@@ -263,6 +263,14 @@ void MacroAssembler::SafePush(const Immediate& x) {
 }
 
 
+void MacroAssembler::CompareRoot(Register with, Heap::RootListIndex index) {
+  // see ROOT_ACCESSOR macro in factory.h
+  Handle<Object> value(BitCast<Object**>(
+      &isolate()->heap()->roots_address()[index]));
+  cmp(with, value);
+}
+
+
 void MacroAssembler::CmpObjectType(Register heap_object,
                                    InstanceType type,
                                    Register map) {

src/ia32/macro-assembler-ia32.h

@@ -209,6 +209,9 @@ class MacroAssembler: public Assembler {
   void SafeSet(Register dst, const Immediate& x);
   void SafePush(const Immediate& x);
 
+  // Compare a register against a known root, e.g. undefined, null, true, ...
+  void CompareRoot(Register with, Heap::RootListIndex index);
+
   // Compare object type for heap object.
   // Incoming register is heap_object and outgoing register is map.
   void CmpObjectType(Register heap_object, InstanceType type, Register map);

src/x64/code-stubs-x64.cc

@@ -230,68 +230,151 @@ void FastCloneShallowArrayStub::Generate(MacroAssembler* masm) {
 }
 
 
-// The stub returns zero for false, and a non-zero value for true.
+// The stub expects its argument on the stack and returns its result in tos_:
+// zero for false, and a non-zero value for true.
 void ToBooleanStub::Generate(MacroAssembler* masm) {
-  Label false_result, true_result, not_string;
+  Label patch;
+  const Register argument = rax;
   const Register map = rdx;
 
-  __ movq(rax, Operand(rsp, 1 * kPointerSize));
+  if (!types_.IsEmpty()) {
+    __ movq(argument, Operand(rsp, 1 * kPointerSize));
+  }
 
   // undefined -> false
-  __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
-  __ j(equal, &false_result);
+  CheckOddball(masm, UNDEFINED, Heap::kUndefinedValueRootIndex, false, &patch);
 
   // Boolean -> its value
-  __ CompareRoot(rax, Heap::kFalseValueRootIndex);
-  __ j(equal, &false_result);
-  __ CompareRoot(rax, Heap::kTrueValueRootIndex);
-  __ j(equal, &true_result);
-
-  // Smis: 0 -> false, all other -> true
-  __ Cmp(rax, Smi::FromInt(0));
-  __ j(equal, &false_result);
-  __ JumpIfSmi(rax, &true_result);
+  CheckOddball(masm, BOOLEAN, Heap::kFalseValueRootIndex, false, &patch);
+  CheckOddball(masm, BOOLEAN, Heap::kTrueValueRootIndex, true, &patch);
 
   // 'null' -> false.
-  __ CompareRoot(rax, Heap::kNullValueRootIndex);
-  __ j(equal, &false_result, Label::kNear);
+  CheckOddball(masm, NULL_TYPE, Heap::kNullValueRootIndex, false, &patch);
+
+  if (types_.Contains(SMI)) {
+    // Smis: 0 -> false, all other -> true
+    Label not_smi;
+    __ JumpIfNotSmi(argument, &not_smi, Label::kNear);
+    // argument contains the correct return value already
+    if (!tos_.is(argument)) {
+      __ movq(tos_, argument);
+    }
+    __ ret(1 * kPointerSize);
+    __ bind(&not_smi);
+  } else if (types_.NeedsMap()) {
+    // If we need a map later and have a Smi -> patch.
+    __ JumpIfSmi(argument, &patch, Label::kNear);
+  }
 
-  // Get the map of the heap object.
-  __ movq(map, FieldOperand(rax, HeapObject::kMapOffset));
+  if (types_.NeedsMap()) {
+    __ movq(map, FieldOperand(argument, HeapObject::kMapOffset));
 
-  // Undetectable -> false.
-  __ testb(FieldOperand(map, Map::kBitFieldOffset),
-           Immediate(1 << Map::kIsUndetectable));
-  __ j(not_zero, &false_result, Label::kNear);
+    // Everything with a map could be undetectable, so check this now.
+    __ testb(FieldOperand(map, Map::kBitFieldOffset),
+             Immediate(1 << Map::kIsUndetectable));
+    // Undetectable -> false.
+    Label not_undetectable;
+    __ j(zero, &not_undetectable, Label::kNear);
+    __ Set(tos_, 0);
+    __ ret(1 * kPointerSize);
+    __ bind(&not_undetectable);
+  }
 
-  // JavaScript object -> true.
-  __ CmpInstanceType(map, FIRST_SPEC_OBJECT_TYPE);
-  __ j(above_equal, &true_result, Label::kNear);
+  if (types_.Contains(SPEC_OBJECT)) {
+    // spec object -> true.
+    Label not_js_object;
+    __ CmpInstanceType(map, FIRST_SPEC_OBJECT_TYPE);
+    __ j(below, &not_js_object, Label::kNear);
+    __ Set(tos_, 1);
+    __ ret(1 * kPointerSize);
+    __ bind(&not_js_object);
+  } else if (types_.Contains(INTERNAL_OBJECT)) {
+    // We've seen a spec object for the first time -> patch.
+    __ CmpInstanceType(map, FIRST_SPEC_OBJECT_TYPE);
+    __ j(above_equal, &patch, Label::kNear);
+  }
 
-  // String value -> false iff empty.
-  __ CmpInstanceType(map, FIRST_NONSTRING_TYPE);
-  __ j(above_equal, &not_string, Label::kNear);
-  __ cmpq(FieldOperand(rax, String::kLengthOffset), Immediate(0));
-  __ j(zero, &false_result, Label::kNear);
-  __ jmp(&true_result, Label::kNear);
+  if (types_.Contains(STRING)) {
+    // String value -> false iff empty.
+    Label not_string;
+    __ CmpInstanceType(map, FIRST_NONSTRING_TYPE);
+    __ j(above_equal, &not_string, Label::kNear);
+    __ movq(tos_, FieldOperand(argument, String::kLengthOffset));
+    __ ret(1 * kPointerSize);  // the string length is OK as the return value
+    __ bind(&not_string);
+  } else if (types_.Contains(INTERNAL_OBJECT)) {
+    // We've seen a string for the first time -> patch
+    __ CmpInstanceType(map, FIRST_NONSTRING_TYPE);
+    __ j(below, &patch, Label::kNear);
+  }
 
-  __ bind(&not_string);
-  // HeapNumber -> false iff +0, -0, or NaN.
-  // These three cases set the zero flag when compared to zero using ucomisd.
-  __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
-  __ j(not_equal, &true_result, Label::kNear);
-  __ xorps(xmm0, xmm0);
-  __ ucomisd(xmm0, FieldOperand(rax, HeapNumber::kValueOffset));
-  __ j(zero, &false_result, Label::kNear);
-  // Fall through to |true_result|.
+  if (types_.Contains(HEAP_NUMBER)) {
+    // heap number -> false iff +0, -0, or NaN.
+    Label not_heap_number, false_result;
+    __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
+    __ j(not_equal, &not_heap_number, Label::kNear);
+    __ xorps(xmm0, xmm0);
+    __ ucomisd(xmm0, FieldOperand(argument, HeapNumber::kValueOffset));
+    __ j(zero, &false_result, Label::kNear);
+    __ Set(tos_, 1);
+    __ ret(1 * kPointerSize);
+    __ bind(&false_result);
+    __ Set(tos_, 0);
+    __ ret(1 * kPointerSize);
+    __ bind(&not_heap_number);
+  } else if (types_.Contains(INTERNAL_OBJECT)) {
+    // We've seen a heap number for the first time -> patch
+    __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
+    __ j(equal, &patch, Label::kNear);
+  }
 
-  // Return 1/0 for true/false in tos_.
-  __ bind(&true_result);
-  __ Set(tos_, 1);
-  __ ret(1 * kPointerSize);
-  __ bind(&false_result);
-  __ Set(tos_, 0);
-  __ ret(1 * kPointerSize);
+  if (types_.Contains(INTERNAL_OBJECT)) {
+    // internal objects -> true
+    __ Set(tos_, 1);
+    __ ret(1 * kPointerSize);
+  }
+
+  if (!types_.IsAll()) {
+    __ bind(&patch);
+    GenerateTypeTransition(masm);
+  }
+}
+
+
+void ToBooleanStub::CheckOddball(MacroAssembler* masm,
+                                 Type type,
+                                 Heap::RootListIndex value,
+                                 bool result,
+                                 Label* patch) {
+  const Register argument = rax;
+  if (types_.Contains(type)) {
+    // If we see an expected oddball, return its ToBoolean value tos_.
+    Label different_value;
+    __ CompareRoot(argument, value);
+    __ j(not_equal, &different_value, Label::kNear);
+    __ Set(tos_, result ? 1 : 0);
+    __ ret(1 * kPointerSize);
+    __ bind(&different_value);
+  } else if (types_.Contains(INTERNAL_OBJECT)) {
+    // If we see an unexpected oddball and handle internal objects, we must
+    // patch because the code for internal objects doesn't handle it explictly.
+    __ CompareRoot(argument, value);
+    __ j(equal, patch);
+  }
+}
+
+
+void ToBooleanStub::GenerateTypeTransition(MacroAssembler* masm) {
+  __ pop(rcx);  // Get return address, operand is now on top of stack.
+  __ Push(Smi::FromInt(tos_.code()));
+  __ Push(Smi::FromInt(types_.ToByte()));
+  __ push(rcx);  // Push return address.
+  // Patch the caller to an appropriate specialized stub and return the
+  // operation result to the caller of the stub.
+  __ TailCallExternalReference(
+      ExternalReference(IC_Utility(IC::kToBoolean_Patch), masm->isolate()),
+      3,
+      1);
 }
 
 

src/x64/lithium-codegen-x64.cc

@@ -1402,39 +1402,119 @@ void LCodeGen::DoBranch(LBranch* instr) {
       Label* true_label = chunk_->GetAssemblyLabel(true_block);
       Label* false_label = chunk_->GetAssemblyLabel(false_block);
 
-      __ CompareRoot(reg, Heap::kUndefinedValueRootIndex);
-      __ j(equal, false_label);
-      __ CompareRoot(reg, Heap::kTrueValueRootIndex);
-      __ j(equal, true_label);
-      __ CompareRoot(reg, Heap::kFalseValueRootIndex);
-      __ j(equal, false_label);
-      __ Cmp(reg, Smi::FromInt(0));
-      __ j(equal, false_label);
-      __ JumpIfSmi(reg, true_label);
-
-      // Test for double values. Plus/minus zero and NaN are false.
-      Label call_stub;
-      __ CompareRoot(FieldOperand(reg, HeapObject::kMapOffset),
-                     Heap::kHeapNumberMapRootIndex);
-      __ j(not_equal, &call_stub, Label::kNear);
-
-      // HeapNumber => false iff +0, -0, or NaN. These three cases set the
-      // zero flag when compared to zero using ucomisd.
-      __ xorps(xmm0, xmm0);
-      __ ucomisd(xmm0, FieldOperand(reg, HeapNumber::kValueOffset));
-      __ j(zero, false_label);
-      __ jmp(true_label);
-
-      // The conversion stub doesn't cause garbage collections so it's
-      // safe to not record a safepoint after the call.
-      __ bind(&call_stub);
-      ToBooleanStub stub(rax);
-      __ Pushad();
-      __ push(reg);
-      __ CallStub(&stub);
-      __ testq(rax, rax);
-      __ Popad();
-      EmitBranch(true_block, false_block, not_zero);
+      ToBooleanStub::Types expected = instr->hydrogen()->expected_input_types();
+      // Avoid deopts in the case where we've never executed this path before.
+      if (expected.IsEmpty()) expected = ToBooleanStub::all_types();
+
+      if (expected.Contains(ToBooleanStub::UNDEFINED)) {
+        // undefined -> false.
+        __ CompareRoot(reg, Heap::kUndefinedValueRootIndex);
+        __ j(equal, false_label);
+      } else if (expected.Contains(ToBooleanStub::INTERNAL_OBJECT)) {
+        // We've seen undefined for the first time -> deopt.
+        __ CompareRoot(reg, Heap::kUndefinedValueRootIndex);
+        DeoptimizeIf(equal, instr->environment());
+      }
+
+      if (expected.Contains(ToBooleanStub::BOOLEAN)) {
+        // true -> true.
+        __ CompareRoot(reg, Heap::kTrueValueRootIndex);
+        __ j(equal, true_label);
+      } else if (expected.Contains(ToBooleanStub::INTERNAL_OBJECT)) {
+        // We've seen a boolean for the first time -> deopt.
+        __ CompareRoot(reg, Heap::kTrueValueRootIndex);
+        DeoptimizeIf(equal, instr->environment());
+      }
+
+      if (expected.Contains(ToBooleanStub::BOOLEAN)) {
+        // false -> false.
+        __ CompareRoot(reg, Heap::kFalseValueRootIndex);
+        __ j(equal, false_label);
+      } else if (expected.Contains(ToBooleanStub::INTERNAL_OBJECT)) {
+        // We've seen a boolean for the first time -> deopt.
+        __ CompareRoot(reg, Heap::kFalseValueRootIndex);
+        DeoptimizeIf(equal, instr->environment());
+      }
+
+      if (expected.Contains(ToBooleanStub::NULL_TYPE)) {
+        // 'null' -> false.
+        __ CompareRoot(reg, Heap::kNullValueRootIndex);
+        __ j(equal, false_label);
+      } else if (expected.Contains(ToBooleanStub::INTERNAL_OBJECT)) {
+        // We've seen null for the first time -> deopt.
+        __ CompareRoot(reg, Heap::kNullValueRootIndex);
+        DeoptimizeIf(equal, instr->environment());
+      }
+
+      if (expected.Contains(ToBooleanStub::SMI)) {
+        // Smis: 0 -> false, all other -> true.
+        __ Cmp(reg, Smi::FromInt(0));
+        __ j(equal, false_label);
+        __ JumpIfSmi(reg, true_label);
+      } else if (expected.NeedsMap()) {
+        // If we need a map later and have a Smi -> deopt.
+        __ testb(reg, Immediate(kSmiTagMask));
+        DeoptimizeIf(zero, instr->environment());
+      }
+
+      const Register map = kScratchRegister;
+      if (expected.NeedsMap()) {
+        __ movq(map, FieldOperand(reg, HeapObject::kMapOffset));
+        // Everything with a map could be undetectable, so check this now.
+        __ testb(FieldOperand(map, Map::kBitFieldOffset),
+                 Immediate(1 << Map::kIsUndetectable));
+        // Undetectable -> false.
+        __ j(not_zero, false_label);
+      }
+
+      if (expected.Contains(ToBooleanStub::SPEC_OBJECT)) {
+        // spec object -> true.
+        __ CmpInstanceType(map, FIRST_SPEC_OBJECT_TYPE);
+        __ j(above_equal, true_label);
+      } else if (expected.Contains(ToBooleanStub::INTERNAL_OBJECT)) {
+        // We've seen a spec object for the first time -> deopt.
+        __ CmpInstanceType(map, FIRST_SPEC_OBJECT_TYPE);
+        DeoptimizeIf(above_equal, instr->environment());
+      }
+
+      if (expected.Contains(ToBooleanStub::STRING)) {
+        // String value -> false iff empty.
+        Label not_string;
+        __ CmpInstanceType(map, FIRST_NONSTRING_TYPE);
+        __ j(above_equal, &not_string, Label::kNear);
+        __ cmpq(FieldOperand(reg, String::kLengthOffset), Immediate(0));
+        __ j(not_zero, true_label);
+        __ jmp(false_label);
+        __ bind(&not_string);
+      } else if (expected.Contains(ToBooleanStub::INTERNAL_OBJECT)) {
+        // We've seen a string for the first time -> deopt
+        __ CmpInstanceType(map, FIRST_NONSTRING_TYPE);
+        DeoptimizeIf(below, instr->environment());
+      }
+
+      if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
+        // heap number -> false iff +0, -0, or NaN.
+        Label not_heap_number;
+        __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
+        __ j(not_equal, &not_heap_number, Label::kNear);
+        __ xorps(xmm0, xmm0);
+        __ ucomisd(xmm0, FieldOperand(reg, HeapNumber::kValueOffset));
+        __ j(zero, false_label);
+        __ jmp(true_label);
+        __ bind(&not_heap_number);
+      } else if (expected.Contains(ToBooleanStub::INTERNAL_OBJECT)) {
+        // We've seen a heap number for the first time -> deopt.
+        __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
+        DeoptimizeIf(equal, instr->environment());
+      }
+
+      if (expected.Contains(ToBooleanStub::INTERNAL_OBJECT)) {
+        // internal objects -> true
+        __ jmp(true_label);
+      } else {
+        // We've seen something for the first time -> deopt.
+        DeoptimizeIf(no_condition, instr->environment());
+      }
     }
   }
 }

src/x64/lithium-x64.cc

@@ -1036,7 +1036,11 @@ LInstruction* LChunkBuilder::DoBranch(HBranch* instr) {
         : instr->SecondSuccessor();
     return new LGoto(successor->block_id());
   }
-  return new LBranch(UseRegisterAtStart(v));
+  LInstruction* branch = new LBranch(UseRegister(v));
+  // When we handle all cases, we never deopt, so we don't need to assign the
+  // environment then.
+  bool all_cases_handled = instr->expected_input_types().IsAll();
+  return all_cases_handled ? branch : AssignEnvironment(branch);
 }