Prevent deopt when assigning double values to typed arrays

src/ia32/lithium-ia32.cc

 // Copyright 2011 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 786 matching lines @@
 }
 
 
 LInstruction* LChunkBuilder::DoDeoptimize(HDeoptimize* instr) {
   return AssignEnvironment(new LDeoptimize);
 }
 
 
 LInstruction* LChunkBuilder::DoBit(Token::Value op,
                                    HBitwiseBinaryOperation* instr) {
-  if (instr->representation().IsInteger32()) {
-    ASSERT(instr->left()->representation().IsInteger32());
-    ASSERT(instr->right()->representation().IsInteger32());
+  if (instr->representation().IsInteger()) {
+    ASSERT(instr->left()->representation().IsInteger());
+    ASSERT(instr->right()->representation().IsInteger());
 
     LOperand* left = UseRegisterAtStart(instr->LeastConstantOperand());
     LOperand* right = UseOrConstantAtStart(instr->MostConstantOperand());
     return DefineSameAsFirst(new LBitI(op, left, right));
   } else {
     ASSERT(instr->representation().IsTagged());
     ASSERT(instr->left()->representation().IsTagged());
     ASSERT(instr->right()->representation().IsTagged());
 
     LOperand* left = UseFixed(instr->left(), edx);
     LOperand* right = UseFixed(instr->right(), eax);
     LArithmeticT* result = new LArithmeticT(op, left, right);
     return MarkAsCall(DefineFixed(result, eax), instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoShift(Token::Value op,
                                      HBitwiseBinaryOperation* instr) {
   if (instr->representation().IsTagged()) {
     ASSERT(instr->left()->representation().IsTagged());
     ASSERT(instr->right()->representation().IsTagged());
 
     LOperand* left = UseFixed(instr->left(), edx);
     LOperand* right = UseFixed(instr->right(), eax);
     LArithmeticT* result = new LArithmeticT(op, left, right);
     return MarkAsCall(DefineFixed(result, eax), instr);
   }
 
-  ASSERT(instr->representation().IsInteger32());
-  ASSERT(instr->OperandAt(0)->representation().IsInteger32());
-  ASSERT(instr->OperandAt(1)->representation().IsInteger32());
+  ASSERT(instr->representation().IsInteger());
+  ASSERT(instr->OperandAt(0)->representation().IsInteger32X());
+  ASSERT(instr->OperandAt(1)->representation().IsInteger32X());
   LOperand* left = UseRegisterAtStart(instr->OperandAt(0));
 
   HValue* right_value = instr->OperandAt(1);
   LOperand* right = NULL;
   int constant_value = 0;
   if (right_value->IsConstant()) {
     HConstant* constant = HConstant::cast(right_value);
     right = chunk_->DefineConstantOperand(constant);
     constant_value = constant->Integer32Value() & 0x1f;
   } else {
     right = UseFixed(right_value, ecx);
   }
 
   // Shift operations can only deoptimize if we do a logical shift
   // by 0 and the result cannot be truncated to int32.
-  bool can_deopt = (op == Token::SHR && constant_value == 0);
-  if (can_deopt) {
-    bool can_truncate = true;
-    for (int i = 0; i < instr->uses()->length(); i++) {
-      if (!instr->uses()->at(i)->CheckFlag(HValue::kTruncatingToInt32)) {
-        can_truncate = false;
-        break;
-      }
-    }
-    can_deopt = !can_truncate;
-  }
+  bool can_deopt = op == Token::SHR &&
+      constant_value == 0 &&
+      !instr->representation().Equals(Representation::TruncatedInteger32());
 
   LShiftI* result = new LShiftI(op, left, right, can_deopt);
   return can_deopt
       ? AssignEnvironment(DefineSameAsFirst(result))
       : DefineSameAsFirst(result);
 }
 
 
 LInstruction* LChunkBuilder::DoArithmeticD(Token::Value op,
                                            HArithmeticBinaryOperation* instr) {
@@ skipping 168 matching lines @@
 
       return new LClassOfTestAndBranch(UseTempRegister(compare->value()),
                                        TempRegister(),
                                        TempRegister());
     } else if (v->IsCompare()) {
       HCompare* compare = HCompare::cast(v);
       Token::Value op = compare->token();
       HValue* left = compare->left();
       HValue* right = compare->right();
       Representation r = compare->GetInputRepresentation();
-      if (r.IsInteger32()) {
-        ASSERT(left->representation().IsInteger32());
-        ASSERT(right->representation().IsInteger32());
+      if (r.IsInteger()) {
+        ASSERT(left->representation().IsInteger());
+        ASSERT(right->representation().IsInteger());
 
         return new LCmpIDAndBranch(UseRegisterAtStart(left),
                                    UseOrConstantAtStart(right));
       } else if (r.IsDouble()) {
         ASSERT(left->representation().IsDouble());
         ASSERT(right->representation().IsDouble());
 
         return new LCmpIDAndBranch(UseRegisterAtStart(left),
                                    UseRegisterAtStart(right));
       } else {
@@ skipping 273 matching lines @@
   return DoShift(Token::SHL, instr);
 }
 
 
 LInstruction* LChunkBuilder::DoBitAnd(HBitAnd* instr) {
   return DoBit(Token::BIT_AND, instr);
 }
 
 
 LInstruction* LChunkBuilder::DoBitNot(HBitNot* instr) {
-  ASSERT(instr->value()->representation().IsInteger32());
-  ASSERT(instr->representation().IsInteger32());
+  ASSERT(instr->value()->representation().IsInteger());
+  ASSERT(instr->representation().IsInteger32X());
   LOperand* input = UseRegisterAtStart(instr->value());
   LBitNotI* result = new LBitNotI(input);
   return DefineSameAsFirst(result);
 }
 
 
 LInstruction* LChunkBuilder::DoBitOr(HBitOr* instr) {
   return DoBit(Token::BIT_OR, instr);
 }
 
 
 LInstruction* LChunkBuilder::DoBitXor(HBitXor* instr) {
   return DoBit(Token::BIT_XOR, instr);
 }
 
 
 LInstruction* LChunkBuilder::DoDiv(HDiv* instr) {
   if (instr->representation().IsDouble()) {
     return DoArithmeticD(Token::DIV, instr);
-  } else if (instr->representation().IsInteger32()) {
+  } else if (instr->representation().IsInteger()) {
+    ASSERT(instr->representation().IsInteger32X());
     // The temporary operand is necessary to ensure that right is not allocated
     // into edx.
     LOperand* temp = FixedTemp(edx);
     LOperand* dividend = UseFixed(instr->left(), eax);
     LOperand* divisor = UseRegister(instr->right());
     LDivI* result = new LDivI(dividend, divisor, temp);
     return AssignEnvironment(DefineFixed(result, eax));
   } else {
     ASSERT(instr->representation().IsTagged());
     return DoArithmeticT(Token::DIV, instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoMod(HMod* instr) {
-  if (instr->representation().IsInteger32()) {
-    ASSERT(instr->left()->representation().IsInteger32());
-    ASSERT(instr->right()->representation().IsInteger32());
+  if (instr->representation().IsInteger32X()) {
+    ASSERT(instr->left()->representation().IsInteger());
+    ASSERT(instr->right()->representation().IsInteger());
 
     LInstruction* result;
     if (instr->HasPowerOf2Divisor()) {
       ASSERT(!instr->CheckFlag(HValue::kCanBeDivByZero));
       LOperand* value = UseRegisterAtStart(instr->left());
       LModI* mod = new LModI(value, UseOrConstant(instr->right()), NULL);
       result = DefineSameAsFirst(mod);
     } else {
       // The temporary operand is necessary to ensure that right is
       // not allocated into edx.
@@ skipping 17 matching lines @@
     // TODO(fschneider): Allow any register as input registers.
     LOperand* left = UseFixedDouble(instr->left(), xmm2);
     LOperand* right = UseFixedDouble(instr->right(), xmm1);
     LArithmeticD* result = new LArithmeticD(Token::MOD, left, right);
     return MarkAsCall(DefineFixedDouble(result, xmm1), instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoMul(HMul* instr) {
-  if (instr->representation().IsInteger32()) {
-    ASSERT(instr->left()->representation().IsInteger32());
-    ASSERT(instr->right()->representation().IsInteger32());
+  if (instr->representation().IsInteger32X()) {
+    ASSERT(instr->left()->representation().IsInteger());
+    ASSERT(instr->right()->representation().IsInteger());
     LOperand* left = UseRegisterAtStart(instr->LeastConstantOperand());
     LOperand* right = UseOrConstant(instr->MostConstantOperand());
     LOperand* temp = NULL;
     if (instr->CheckFlag(HValue::kBailoutOnMinusZero)) {
       temp = TempRegister();
     }
     LMulI* mul = new LMulI(left, right, temp);
     return AssignEnvironment(DefineSameAsFirst(mul));
   } else if (instr->representation().IsDouble()) {
     return DoArithmeticD(Token::MUL, instr);
   } else {
     ASSERT(instr->representation().IsTagged());
     return DoArithmeticT(Token::MUL, instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoSub(HSub* instr) {
-  if (instr->representation().IsInteger32()) {
-    ASSERT(instr->left()->representation().IsInteger32());
-    ASSERT(instr->right()->representation().IsInteger32());
+  if (instr->representation().IsInteger32X()) {
+    ASSERT(instr->left()->representation().IsInteger());
+    ASSERT(instr->right()->representation().IsInteger());
     LOperand* left = UseRegisterAtStart(instr->left());
     LOperand* right = UseOrConstantAtStart(instr->right());
     LSubI* sub = new LSubI(left, right);
     LInstruction* result = DefineSameAsFirst(sub);
     if (instr->CheckFlag(HValue::kCanOverflow)) {
       result = AssignEnvironment(result);
     }
     return result;
   } else if (instr->representation().IsDouble()) {
     return DoArithmeticD(Token::SUB, instr);
   } else {
     ASSERT(instr->representation().IsTagged());
     return DoArithmeticT(Token::SUB, instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoAdd(HAdd* instr) {
-  if (instr->representation().IsInteger32()) {
-    ASSERT(instr->left()->representation().IsInteger32());
-    ASSERT(instr->right()->representation().IsInteger32());
+  if (instr->representation().IsInteger32X()) {
+    ASSERT(instr->left()->representation().IsInteger());
+    ASSERT(instr->right()->representation().IsInteger());
     LOperand* left = UseRegisterAtStart(instr->LeastConstantOperand());
     LOperand* right = UseOrConstantAtStart(instr->MostConstantOperand());
     LAddI* add = new LAddI(left, right);
     LInstruction* result = DefineSameAsFirst(add);
     if (instr->CheckFlag(HValue::kCanOverflow)) {
       result = AssignEnvironment(result);
     }
     return result;
   } else if (instr->representation().IsDouble()) {
     return DoArithmeticD(Token::ADD, instr);
@@ skipping 16 matching lines @@
       UseFixed(instr->right(), eax);
   LPower* result = new LPower(left, right);
   return MarkAsCall(DefineFixedDouble(result, xmm3), instr,
                     CAN_DEOPTIMIZE_EAGERLY);
 }
 
 
 LInstruction* LChunkBuilder::DoCompare(HCompare* instr) {
   Token::Value op = instr->token();
   Representation r = instr->GetInputRepresentation();
-  if (r.IsInteger32()) {
-    ASSERT(instr->left()->representation().IsInteger32());
-    ASSERT(instr->right()->representation().IsInteger32());
+  if (r.IsInteger32X()) {
+    ASSERT(instr->left()->representation().IsInteger());
+    ASSERT(instr->right()->representation().IsInteger());
     LOperand* left = UseRegisterAtStart(instr->left());
     LOperand* right = UseOrConstantAtStart(instr->right());
     return DefineAsRegister(new LCmpID(left, right));
   } else if (r.IsDouble()) {
     ASSERT(instr->left()->representation().IsDouble());
     ASSERT(instr->right()->representation().IsDouble());
     LOperand* left = UseRegisterAtStart(instr->left());
     LOperand* right = UseRegisterAtStart(instr->right());
     return DefineAsRegister(new LCmpID(left, right));
   } else {
@@ skipping 122 matching lines @@
 
 LInstruction* LChunkBuilder::DoChange(HChange* instr) {
   Representation from = instr->from();
   Representation to = instr->to();
   if (from.IsTagged()) {
     if (to.IsDouble()) {
       LOperand* value = UseRegister(instr->value());
       LNumberUntagD* res = new LNumberUntagD(value);
       return AssignEnvironment(DefineAsRegister(res));
     } else {
-      ASSERT(to.IsInteger32());
+      ASSERT(to.IsInteger());
       LOperand* value = UseRegister(instr->value());
       bool needs_check = !instr->value()->type().IsSmi();
+      bool needs_temp = to.IsClampedRoundedInteger8() ||
+          (!(CpuFeatures::IsSupported(SSE3) && to.IsTruncatedInteger32()));
+      ToIRoundingMode rounding_mode(RepresentationToRoundingMode(to));
       if (needs_check) {
-        LOperand* xmm_temp =
-            (instr->CanTruncateToInt32() && CpuFeatures::IsSupported(SSE3))
-            ? NULL
-            : FixedTemp(xmm1);
-        LTaggedToI* res = new LTaggedToI(value, xmm_temp);
+        LOperand* xmm_temp = needs_temp ? FixedTemp(xmm1) : NULL;
+        LTaggedToI* res = new LTaggedToI(value, xmm_temp, rounding_mode);
         return AssignEnvironment(DefineSameAsFirst(res));
       } else {
-        return DefineSameAsFirst(new LSmiUntag(value, needs_check));
+        bool should_clamp = to.IsClampedRoundedInteger8();
+        return DefineSameAsFirst(new LSmiUntag(value,
+                                               false,
+                                               should_clamp));
       }
     }
   } else if (from.IsDouble()) {
     if (to.IsTagged()) {
       LOperand* value = UseRegister(instr->value());
       LOperand* temp = TempRegister();
 
       // Make sure that temp and result_temp are different registers.
       LUnallocated* result_temp = TempRegister();
       LNumberTagD* result = new LNumberTagD(value, temp);
       return AssignPointerMap(Define(result, result_temp));
     } else {
-      ASSERT(to.IsInteger32());
-      bool needs_temp = instr->CanTruncateToInt32() &&
-          !CpuFeatures::IsSupported(SSE3);
+      ASSERT(to.IsInteger());
+      ToIRoundingMode rounding_mode(RepresentationToRoundingMode(to));
+      bool needs_temp = to.IsClampedRoundedInteger8() ||
+          (!(CpuFeatures::IsSupported(SSE3) && to.IsTruncatedInteger32()));
       LOperand* value = needs_temp ?
           UseTempRegister(instr->value()) : UseRegister(instr->value());
       LOperand* temp = needs_temp ? TempRegister() : NULL;
-      return AssignEnvironment(DefineAsRegister(new LDoubleToI(value, temp)));
+      return AssignEnvironment(DefineAsRegister(new LDoubleToI(value,
+                                                               temp,
+                                                               rounding_mode)));
     }
-  } else if (from.IsInteger32()) {
+  } else if (from.IsInteger()) {
     if (to.IsTagged()) {
       HValue* val = instr->value();
       LOperand* value = UseRegister(val);
       if (val->HasRange() && val->range()->IsInSmiRange()) {
         return DefineSameAsFirst(new LSmiTag(value));
       } else {
         LNumberTagI* result = new LNumberTagI(value);
         return AssignEnvironment(AssignPointerMap(DefineSameAsFirst(result)));
       }
+    } else if (to.IsClampedRoundedInteger8()) {
+      return DefineFixed(new LInteger32ToClamped(
+          UseFixed(instr->value(), eax)), eax);
     } else {
       ASSERT(to.IsDouble());
       return DefineAsRegister(new LInteger32ToDouble(Use(instr->value())));
     }
   }
   UNREACHABLE();
   return NULL;
 }
 
 
@@ skipping 37 matching lines @@
 }
 
 
 LInstruction* LChunkBuilder::DoReturn(HReturn* instr) {
   return new LReturn(UseFixed(instr->value(), eax));
 }
 
 
 LInstruction* LChunkBuilder::DoConstant(HConstant* instr) {
   Representation r = instr->representation();
-  if (r.IsInteger32()) {
+  if (r.IsInteger()) {
     return DefineAsRegister(new LConstantI);
   } else if (r.IsDouble()) {
     double value = instr->DoubleValue();
     LOperand* temp = (BitCast<uint64_t, double>(value) != 0)
         ? TempRegister()
         : NULL;
     return DefineAsRegister(new LConstantD(temp));
   } else if (r.IsTagged()) {
     return DefineAsRegister(new LConstantT);
   } else {
@@ skipping 106 matching lines @@
 LInstruction* LChunkBuilder::DoLoadExternalArrayPointer(
     HLoadExternalArrayPointer* instr) {
   LOperand* input = UseRegisterAtStart(instr->value());
   return DefineAsRegister(new LLoadExternalArrayPointer(input));
 }
 
 
 LInstruction* LChunkBuilder::DoLoadKeyedFastElement(
     HLoadKeyedFastElement* instr) {
   ASSERT(instr->representation().IsTagged());
-  ASSERT(instr->key()->representation().IsInteger32());
+  ASSERT(instr->key()->representation().IsInteger32X());
   LOperand* obj = UseRegisterAtStart(instr->object());
   LOperand* key = UseRegisterAtStart(instr->key());
   LLoadKeyedFastElement* result = new LLoadKeyedFastElement(obj, key);
   return AssignEnvironment(DefineSameAsFirst(result));
 }
 
 
 LInstruction* LChunkBuilder::DoLoadKeyedSpecializedArrayElement(
     HLoadKeyedSpecializedArrayElement* instr) {
   ExternalArrayType array_type = instr->array_type();
   Representation representation(instr->representation());
-  ASSERT((representation.IsInteger32() && array_type != kExternalFloatArray) ||
+  ASSERT((representation.IsInteger32X() && array_type != kExternalFloatArray) ||
          (representation.IsDouble() && array_type == kExternalFloatArray));
-  ASSERT(instr->key()->representation().IsInteger32());
+  ASSERT(instr->key()->representation().IsInteger32X());
   LOperand* external_pointer = UseRegister(instr->external_pointer());
   LOperand* key = UseRegister(instr->key());
   LLoadKeyedSpecializedArrayElement* result =
       new LLoadKeyedSpecializedArrayElement(external_pointer,
                                             key);
   LInstruction* load_instr = DefineAsRegister(result);
   // An unsigned int array load might overflow and cause a deopt, make sure it
   // has an environment.
   return (array_type == kExternalUnsignedIntArray)
       ? AssignEnvironment(load_instr)
       : load_instr;
 }
 
 
 LInstruction* LChunkBuilder::DoLoadKeyedGeneric(HLoadKeyedGeneric* instr) {
   LOperand* context = UseFixed(instr->context(), esi);
   LOperand* object = UseFixed(instr->object(), edx);
   LOperand* key = UseFixed(instr->key(), eax);
 
   LLoadKeyedGeneric* result = new LLoadKeyedGeneric(context, object, key);
   return MarkAsCall(DefineFixed(result, eax), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoStoreKeyedFastElement(
     HStoreKeyedFastElement* instr) {
   bool needs_write_barrier = instr->NeedsWriteBarrier();
   ASSERT(instr->value()->representation().IsTagged());
   ASSERT(instr->object()->representation().IsTagged());
-  ASSERT(instr->key()->representation().IsInteger32());
+  ASSERT(instr->key()->representation().IsInteger32X());
 
   LOperand* obj = UseTempRegister(instr->object());
   LOperand* val = needs_write_barrier
       ? UseTempRegister(instr->value())
       : UseRegisterAtStart(instr->value());
   LOperand* key = needs_write_barrier
       ? UseTempRegister(instr->key())
       : UseRegisterOrConstantAtStart(instr->key());
 
   return AssignEnvironment(new LStoreKeyedFastElement(obj, key, val));
 }
 
 
 LInstruction* LChunkBuilder::DoStoreKeyedSpecializedArrayElement(
     HStoreKeyedSpecializedArrayElement* instr) {
   Representation representation(instr->value()->representation());
   ExternalArrayType array_type = instr->array_type();
-  ASSERT((representation.IsInteger32() && array_type != kExternalFloatArray) ||
-         (representation.IsDouble() && array_type == kExternalFloatArray));
   ASSERT(instr->external_pointer()->representation().IsExternal());
-  ASSERT(instr->key()->representation().IsInteger32());
+  ASSERT(instr->key()->representation().IsInteger32X());
 
   LOperand* external_pointer = UseRegister(instr->external_pointer());
   LOperand* key = UseRegister(instr->key());
-  LOperand* temp = NULL;
-
-  if (array_type == kExternalPixelArray) {
-    // The generated code for pixel array stores requires that the clamped value
-    // is in a byte register. eax is an arbitrary choice to satisfy this
-    // requirement.
-    temp = FixedTemp(eax);
-  }
 
   LOperand* val = NULL;
   if (array_type == kExternalByteArray ||
-      array_type == kExternalUnsignedByteArray) {
+      array_type == kExternalUnsignedByteArray ||
+      array_type == kExternalPixelArray) {
     // We need a byte register in this case for the value.
     val = UseFixed(instr->value(), eax);
   } else {
     val = UseRegister(instr->value());
   }
 
   return new LStoreKeyedSpecializedArrayElement(external_pointer,
                                                 key,
-                                                val,
-                                                temp);
+                                                val);
 }
 
 
 LInstruction* LChunkBuilder::DoStoreKeyedGeneric(HStoreKeyedGeneric* instr) {
   LOperand* context = UseFixed(instr->context(), esi);
   LOperand* object = UseFixed(instr->object(), edx);
   LOperand* key = UseFixed(instr->key(), ecx);
   LOperand* value = UseFixed(instr->value(), eax);
 
   ASSERT(instr->object()->representation().IsTagged());
@@ skipping 215 matching lines @@
 LInstruction* LChunkBuilder::DoLeaveInlined(HLeaveInlined* instr) {
   HEnvironment* outer = current_block_->last_environment()->outer();
   current_block_->UpdateEnvironment(outer);
   return NULL;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32