Hydrogenisation of binops

src/hydrogen.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 7409 matching lines @@
     CreateJoin(materialize_false, materialize_true, expr->id());
   set_current_block(join);
   if (join != NULL) return ast_context()->ReturnValue(Pop());
 }
 
 
 HInstruction* HOptimizedGraphBuilder::BuildIncrement(
     bool returns_original_input,
     CountOperation* expr) {
   // The input to the count operation is on top of the expression stack.
-  TypeInfo info = expr->type();
+  Handle<Type> info = expr->type();
   Representation rep = Representation::FromType(info);
   if (rep.IsNone() || rep.IsTagged()) {
     rep = Representation::Smi();
   }
 
   if (returns_original_input) {
     // We need an explicit HValue representing ToNumber(input).  The
     // actual HChange instruction we need is (sometimes) added in a later
     // phase, so it is not available now to be used as an input to HAdd and
     // as the return value.
@@ skipping 190 matching lines @@
     return false;
   }
   return (sub->right() == sa);
 }
 
 
 // Checks if the left and the right are shift instructions with the oposite
 // directions that can be replaced by one rotate right instruction or not.
 // Returns the operand and the shift amount for the rotate instruction in the
 // former case.
-bool HOptimizedGraphBuilder::MatchRotateRight(HValue* left,
-                                              HValue* right,
-                                              HValue** operand,
-                                              HValue** shift_amount) {
+bool HGraphBuilder::MatchRotateRight(HValue* left,
+                                     HValue* right,
+                                     HValue** operand,
+                                     HValue** shift_amount) {
   HShl* shl;
   HShr* shr;
   if (left->IsShl() && right->IsShr()) {
     shl = HShl::cast(left);
     shr = HShr::cast(right);
   } else if (left->IsShr() && right->IsShl()) {
     shl = HShl::cast(right);
     shr = HShr::cast(left);
   } else {
     return false;
@@ skipping 15 matching lines @@
     HConstant* right_const = HConstant::cast(right);
     if (right_const->HasInteger32Value() &&
        (right_const->Integer32Value() & 0x1f) != 0) {
       return false;
     }
   }
   return true;
 }
 
 
+HValue* HGraphBuilder::EnforceNumberType(HValue* number,
+                                         Handle<Type> expected) {
+  if (expected->Is(Type::Smi())) {
+    return Add<HForceRepresentation>(number, Representation::Smi());
+  } else if (expected->Is(Type::Signed32())) {
+    return Add<HForceRepresentation>(number, Representation::Integer32());
+  }
+
+  return number;
+}
+
+
 HValue* HGraphBuilder::TruncateToNumber(HValue* value, Handle<Type>* expected) {
   if (value->IsConstant()) {
     HConstant* constant = HConstant::cast(value);
     Maybe<HConstant*> number = constant->CopyToTruncatedNumber(zone());
     if (number.has_value) {
       *expected = handle(Type::Number(), isolate());
       return AddInstruction(number.value);
     }
   }
 
+  NoObservableSideEffectsScope no_effects(this);
+  Handle<Type> expected_type = *expected;
+
+  // Separate the number type from the rest.
+  Handle<Type> expected_obj = handle(Type::Intersect(
+      expected_type, handle(Type::NonNumber(), isolate())), isolate());
+  Handle<Type> expected_number = handle(Type::Intersect(
+      expected_type, handle(Type::Number(), isolate())), isolate());
+
+  // We expect to get a number.
+  // (We need to check first, since Type::None->Is(Type::Any()) == true.
+  if (expected_obj->Is(Type::None())) {
+    ASSERT(!expected_number->Is(Type::None()));
+    return value;
+  }
+
+  if (expected_obj->Is(Type::Undefined())) {
+    // This is already done by HChange.
+    *expected = handle(Type::Union(
+          expected_number, handle(Type::Double(), isolate())), isolate());
+    return value;
+  }
+
+  if (expected_obj->Is(Type::Null())) {
+    *expected = handle(Type::Union(
+          expected_number, handle(Type::Smi(), isolate())), isolate());
+    IfBuilder if_null(this);
+    if_null.If<HCompareObjectEqAndBranch>(value,
+                                          graph()->GetConstantNull());
+    if_null.Then();
+    Push(graph()->GetConstant0());
+    if_null.Else();
+    Push(value);
+    if_null.End();
+    return Pop();
+  }
+
+  if (expected_obj->Is(Type::Boolean())) {
+    *expected = handle(Type::Union(
+          expected_number, handle(Type::Smi(), isolate())), isolate());
+    IfBuilder if_true(this);
+    if_true.If<HCompareObjectEqAndBranch>(value,
+                                          graph()->GetConstantTrue());
+    if_true.Then();
+    Push(graph()->GetConstant1());
+    if_true.Else();
+    IfBuilder if_false(this);
+    if_false.If<HCompareObjectEqAndBranch>(value,
+                                           graph()->GetConstantFalse());
+    if_false.Then();
+    Push(graph()->GetConstant0());
+    if_false.Else();
+    Push(value);
+    if_false.End();
+    if_true.End();
+    return Pop();
+  }
+
   return value;
 }
 
 
 HInstruction* HOptimizedGraphBuilder::BuildBinaryOperation(
     BinaryOperation* expr,
     HValue* left,
     HValue* right) {
   HValue* context = environment()->context();
   Handle<Type> left_type = expr->left()->bounds().lower;
   Handle<Type> right_type = expr->right()->bounds().lower;
   Handle<Type> result_type = expr->bounds().lower;
   Maybe<int> fixed_right_arg = expr->fixed_right_arg();
+
+  return HGraphBuilder::BuildBinaryOperation(expr->op(), left, right,
+      left_type, right_type, result_type, fixed_right_arg, context);
+}
+
+
+HInstruction* HGraphBuilder::BuildBinaryOperation(
+    Token::Value op,
+    HValue* left,
+    HValue* right,
+    Handle<Type> left_type,
+    Handle<Type> right_type,
+    Handle<Type> result_type,
+    Maybe<int> fixed_right_arg,
+    HValue* context) {
+
+  bool is_stub = top_info()->IsStub();
   Representation left_rep = Representation::FromType(left_type);
   Representation right_rep = Representation::FromType(right_type);
+
+  if (left_type->Is(Type::None()) || right_type->Is(Type::None())) {
+    if (left_type->Is(Type::None())) {
+      Add<HDeoptimize>("Insufficient type feedback for LHS of binary operation",
+                       Deoptimizer::SOFT);
+      // TODO(rossberg): we should be able to get rid of non-continuous
+      // defaults.
+      left_type = handle(Type::Any(), isolate());
+    } else {
+      Add<HDeoptimize>("Insufficient type feedback for RHS of binary operation",
+                       Deoptimizer::SOFT);
+      right_type = handle(Type::Any(), isolate());
+    }
+  } else {
+    bool maybe_string_add = op == Token::ADD &&
+                            (left_type->Maybe(Type::String()) ||
+                             right_type->Maybe(Type::String()));
+
+    if (!maybe_string_add) {
+      left = TruncateToNumber(left, &left_type);
+      right = TruncateToNumber(right, &right_type);
+    }
+    if (is_stub) {
+      left = EnforceNumberType(left, left_type);
+      right = EnforceNumberType(right, right_type);
+    }
+
+    left_rep = Representation::FromType(left_type);
+    right_rep = Representation::FromType(right_type);
+  }
+
   Representation result_rep = Representation::FromType(result_type);
 
-  if (expr->op() != Token::ADD ||
-      (left->type().IsNonString() && right->type().IsNonString())) {
-    // For addition we can only truncate the arguments to number if we can
-    // prove that we will not end up in string concatenation mode.
-    left = TruncateToNumber(left, &left_type);
-    right = TruncateToNumber(right, &right_type);
-  }
+  bool is_tagged     = left_rep.IsTagged() || right_rep.IsTagged();
+  bool is_string_add = op == Token::ADD && is_tagged &&
+                       (left_type->Is(Type::String()) ||
+                        right_type->Is(Type::String()));
 
-  if (left_type->Is(Type::None())) {
-    Add<HDeoptimize>("Insufficient type feedback for LHS of binary operation",
-                     Deoptimizer::SOFT);
-    // TODO(rossberg): we should be able to get rid of non-continuous defaults.
-    left_type = handle(Type::Any(), isolate());
-  }
-  if (right_type->Is(Type::None())) {
-    Add<HDeoptimize>("Insufficient type feedback for RHS of binary operation",
-                     Deoptimizer::SOFT);
-    right_type = handle(Type::Any(), isolate());
-  }
   HInstruction* instr = NULL;
-  switch (expr->op()) {
-    case Token::ADD:
-      if (left_type->Is(Type::String()) && right_type->Is(Type::String())) {
-        BuildCheckHeapObject(left);
-        AddInstruction(HCheckInstanceType::NewIsString(left, zone()));
-        BuildCheckHeapObject(right);
-        AddInstruction(HCheckInstanceType::NewIsString(right, zone()));
-        instr = HStringAdd::New(zone(), context, left, right);
-      } else {
-        instr = HAdd::New(zone(), context, left, right);
+  // Only the stub is allowed to call into the runtime, since otherwise we would
+  // inline several instructions (including the two pushes) for every tagged
+  // operation in optimized code, which is more expensive, than a stub call.
+  if (is_stub && is_tagged && !is_string_add) {
+    HValue* function = AddLoadJSBuiltin(BinaryOpIC::TokenToJSBuiltin(op));
+    Add<HPushArgument>(left);
+    Add<HPushArgument>(right);
+    instr = HInvokeFunction::New(zone(), context, function, 2);
+  } else {
+    switch (op) {
+      case Token::ADD:
+        if (is_string_add) {
+          StringAddFlags flags = STRING_ADD_CHECK_BOTH;
+          if (left_type->Is(Type::String())) {
+            BuildCheckHeapObject(left);
+            AddInstruction(HCheckInstanceType::NewIsString(left, zone()));
+            flags = STRING_ADD_CHECK_RIGHT;
+          }
+          if (right_type->Is(Type::String())) {
+            BuildCheckHeapObject(right);
+            AddInstruction(HCheckInstanceType::NewIsString(right, zone()));
+            flags = (flags == STRING_ADD_CHECK_BOTH)
+                ? STRING_ADD_CHECK_LEFT : STRING_ADD_CHECK_NONE;
+          }
+          instr = HStringAdd::New(zone(), context, left, right, flags);
+        } else {
+          instr = HAdd::New(zone(), context, left, right);
+        }
+        break;
+      case Token::SUB:
+        instr = HSub::New(zone(), context, left, right);
+        break;
+      case Token::MUL:
+        instr = HMul::New(zone(), context, left, right);
+        break;
+      case Token::MOD:
+        instr = HMod::New(zone(), context, left, right, fixed_right_arg);
+        break;
+      case Token::DIV:
+        instr = HDiv::New(zone(), context, left, right);
+        break;
+      case Token::BIT_XOR:
+      case Token::BIT_AND:
+        instr = NewUncasted<HBitwise>(op, left, right);
+        break;
+      case Token::BIT_OR: {
+        HValue* operand, *shift_amount;
+        if (left_type->Is(Type::Signed32()) &&
+            right_type->Is(Type::Signed32()) &&
+            MatchRotateRight(left, right, &operand, &shift_amount)) {
+          instr = new(zone()) HRor(context, operand, shift_amount);
+        } else {
+          instr = NewUncasted<HBitwise>(op, left, right);
+        }
+        break;
       }
-      break;
-    case Token::SUB:
-      instr = HSub::New(zone(), context, left, right);
-      break;
-    case Token::MUL:
-      instr = HMul::New(zone(), context, left, right);
-      break;
-    case Token::MOD:
-      instr = HMod::New(zone(), context, left, right, fixed_right_arg);
-      break;
-    case Token::DIV:
-      instr = HDiv::New(zone(), context, left, right);
-      break;
-    case Token::BIT_XOR:
-    case Token::BIT_AND:
-      instr = NewUncasted<HBitwise>(expr->op(), left, right);
-      break;
-    case Token::BIT_OR: {
-      HValue* operand, *shift_amount;
-      if (left_type->Is(Type::Signed32()) &&
-          right_type->Is(Type::Signed32()) &&
-          MatchRotateRight(left, right, &operand, &shift_amount)) {
-        instr = new(zone()) HRor(context, operand, shift_amount);
-      } else {
-        instr = NewUncasted<HBitwise>(expr->op(), left, right);
-      }
-      break;
+      case Token::SAR:
+        instr = HSar::New(zone(), context, left, right);
+        break;
+      case Token::SHR:
+        instr = HShr::New(zone(), context, left, right);
+        if (FLAG_opt_safe_uint32_operations && instr->IsShr() &&
+            CanBeZero(right)) {
+          graph()->RecordUint32Instruction(instr);
+        }
+        break;
+      case Token::SHL:
+        instr = HShl::New(zone(), context, left, right);
+        break;
+      default:
+        UNREACHABLE();
     }
-    case Token::SAR:
-      instr = HSar::New(zone(), context, left, right);
-      break;
-    case Token::SHR:
-      instr = HShr::New(zone(), context, left, right);
-      if (FLAG_opt_safe_uint32_operations && instr->IsShr() &&
-          CanBeZero(right)) {
-        graph()->RecordUint32Instruction(instr);
-      }
-      break;
-    case Token::SHL:
-      instr = HShl::New(zone(), context, left, right);
-      break;
-    default:
-      UNREACHABLE();
   }
 
   if (instr->IsBinaryOperation()) {
     HBinaryOperation* binop = HBinaryOperation::cast(instr);
     binop->set_observed_input_representation(1, left_rep);
     binop->set_observed_input_representation(2, right_rep);
     binop->initialize_output_representation(result_rep);
+    // Stub should not call into stub.
+    if (is_stub) instr->SetFlag(HValue::kCannotBeTagged);
   }
   return instr;
 }
 
 
 // Check for the form (%_ClassOf(foo) === 'BarClass').
 static bool IsClassOfTest(CompareOperation* expr) {
   if (expr->op() != Token::EQ_STRICT) return false;
   CallRuntime* call = expr->left()->AsCallRuntime();
   if (call == NULL) return false;
@@ skipping 1892 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal