X64: Fixed more bad smi operations.

src/x64/codegen-x64.cc

 // Copyright 2009 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 2706 matching lines @@
 
   virtual void Generate();
 
  private:
   Register dst_;
   bool is_increment_;
 };
 
 
 void DeferredPrefixCountOperation::Generate() {
-  // Undo the optimistic smi operation.
-  if (is_increment_) {
-    __ subq(dst_, Immediate(Smi::FromInt(1)));
-  } else {
-    __ addq(dst_, Immediate(Smi::FromInt(1)));
-  }
   __ push(dst_);
   __ InvokeBuiltin(Builtins::TO_NUMBER, CALL_FUNCTION);
   __ push(rax);
   __ push(Immediate(Smi::FromInt(1)));
   if (is_increment_) {
     __ CallRuntime(Runtime::kNumberAdd, 2);
   } else {
     __ CallRuntime(Runtime::kNumberSub, 2);
   }
   if (!dst_.is(rax)) __ movq(dst_, rax);
@@ skipping 15 matching lines @@
   virtual void Generate();
 
  private:
   Register dst_;
   Register old_;
   bool is_increment_;
 };
 
 
 void DeferredPostfixCountOperation::Generate() {
-  // Undo the optimistic smi operation.
-  if (is_increment_) {
-    __ subq(dst_, Immediate(Smi::FromInt(1)));
-  } else {
-    __ addq(dst_, Immediate(Smi::FromInt(1)));
-  }
   __ push(dst_);
   __ InvokeBuiltin(Builtins::TO_NUMBER, CALL_FUNCTION);
 
   // Save the result of ToNumber to use as the old value.
   __ push(rax);
 
   // Call the runtime for the addition or subtraction.
   __ push(rax);
   __ push(Immediate(Smi::FromInt(1)));
   if (is_increment_) {
@@ skipping 36 matching lines @@
     Result old_value;  // Only allocated in the postfix case.
     if (is_postfix) {
       // Allocate a temporary to preserve the old value.
       old_value = allocator_->Allocate();
       ASSERT(old_value.is_valid());
       __ movq(old_value.reg(), new_value.reg());
     }
     // Ensure the new value is writable.
     frame_->Spill(new_value.reg());
 
-    // In order to combine the overflow and the smi tag check, we need
-    // to be able to allocate a byte register.  We attempt to do so
-    // without spilling.  If we fail, we will generate separate overflow
-    // and smi tag checks.
-    //
-    // We allocate and clear the temporary register before
-    // performing the count operation since clearing the register using
-    // xor will clear the overflow flag.
-    Result tmp = allocator_->AllocateWithoutSpilling();
-
-    // Clear scratch register to prepare it for setcc after the operation below.
-    __ xor_(kScratchRegister, kScratchRegister);
-
     DeferredCode* deferred = NULL;
     if (is_postfix) {
       deferred = new DeferredPostfixCountOperation(new_value.reg(),
                                                    old_value.reg(),
                                                    is_increment);
     } else {
       deferred = new DeferredPrefixCountOperation(new_value.reg(),
                                                   is_increment);
     }
 
+    Result tmp = allocator_->AllocateWithoutSpilling();
+    ASSERT(kSmiTagMask == 1 && kSmiTag == 0);
+    __ movl(tmp.reg(), Immediate(kSmiTagMask));
+    // Smi test.
+    __ movq(kScratchRegister, new_value.reg());
     if (is_increment) {
-      __ addq(new_value.reg(), Immediate(Smi::FromInt(1)));
+      __ addl(kScratchRegister, Immediate(Smi::FromInt(1)));
     } else {
-      __ subq(new_value.reg(), Immediate(Smi::FromInt(1)));
+      __ subl(kScratchRegister, Immediate(Smi::FromInt(1)));
     }
-
-    // If the count operation didn't overflow and the result is a valid
-    // smi, we're done. Otherwise, we jump to the deferred slow-case
-    // code.
-
-    // We combine the overflow and the smi tag check.
-    __ setcc(overflow, kScratchRegister);
-    __ or_(kScratchRegister, new_value.reg());
-    __ testl(kScratchRegister, Immediate(kSmiTagMask));
+    // deferred->Branch(overflow);
+    __ cmovl(overflow, kScratchRegister, tmp.reg());
+    __ testl(kScratchRegister, tmp.reg());
     tmp.Unuse();
     deferred->Branch(not_zero);
+    __ movq(new_value.reg(), kScratchRegister);
 
     deferred->BindExit();
 
+
     // Postfix: store the old value in the allocated slot under the
     // reference.
     if (is_postfix) frame_->SetElementAt(target.size(), &old_value);
 
     frame_->Push(&new_value);
     // Non-constant: update the reference.
     if (!is_const) target.SetValue(NOT_CONST_INIT);
   }
 
   // Postfix: drop the new value and use the old.
@@ skipping 2192 matching lines @@
     __ testl(answer.reg(), Immediate(kSmiTagMask));
     deferred->Branch(not_zero);
 
     // Untag both operands.
     __ movq(answer.reg(), left->reg());
     __ sar(answer.reg(), Immediate(kSmiTagSize));
     __ sar(rcx, Immediate(kSmiTagSize));
     // Perform the operation.
     switch (op) {
       case Token::SAR:
-        __ sar(answer.reg());
+        __ sarl(answer.reg());
         // No checks of result necessary
         break;
       case Token::SHR: {
         Label result_ok;
-        __ shr(answer.reg());
+        __ shrl(answer.reg());
         // Check that the *unsigned* result fits in a smi.  Neither of
         // the two high-order bits can be set:
         //  * 0x80000000: high bit would be lost when smi tagging.
         //  * 0x40000000: this number would convert to negative when smi
         //    tagging.
         // These two cases can only happen with shifts by 0 or 1 when
         // handed a valid smi.  If the answer cannot be represented by a
         // smi, restore the left and right arguments, and jump to slow
         // case.  The low bit of the left argument may be lost, but only
         // in a case where it is dropped anyway.
@@ skipping 1706 matching lines @@
       if (use_sse3) {
         // Truncate the operands to 32-bit integers and check for
         // exceptions in doing so.
          CpuFeatures::Scope scope(CpuFeatures::SSE3);
         __ fisttp_s(Operand(rsp, 0 * kPointerSize));
         __ fisttp_s(Operand(rsp, 1 * kPointerSize));
         __ fnstsw_ax();
         __ testl(rax, Immediate(1));
         __ j(not_zero, &operand_conversion_failure);
       } else {
-        // TODO(X64): Verify that SSE3 is always supported, drop this code.
         // Check if right operand is int32.
         __ fist_s(Operand(rsp, 0 * kPointerSize));
         __ fild_s(Operand(rsp, 0 * kPointerSize));
         __ fucompp();
         __ fnstsw_ax();
         __ sahf();  // TODO(X64): Not available.
         __ j(not_zero, &operand_conversion_failure);
         __ j(parity_even, &operand_conversion_failure);
 
         // Check if left operand is int32.
         __ fist_s(Operand(rsp, 1 * kPointerSize));
         __ fild_s(Operand(rsp, 1 * kPointerSize));
         __ fucompp();
         __ fnstsw_ax();
         __ sahf();  // TODO(X64): Not available. Test bits in ax directly
         __ j(not_zero, &operand_conversion_failure);
         __ j(parity_even, &operand_conversion_failure);
       }
 
       // Get int32 operands and perform bitop.
       __ pop(rcx);
       __ pop(rax);
       switch (op_) {
         case Token::BIT_OR:  __ or_(rax, rcx); break;
         case Token::BIT_AND: __ and_(rax, rcx); break;
         case Token::BIT_XOR: __ xor_(rax, rcx); break;
-        case Token::SAR: __ sar(rax); break;
-        case Token::SHL: __ shl(rax); break;
-        case Token::SHR: __ shr(rax); break;
+        case Token::SAR: __ sarl(rax); break;
+        case Token::SHL: __ shll(rax); break;
+        case Token::SHR: __ shrl(rax); break;
         default: UNREACHABLE();
       }
       if (op_ == Token::SHR) {
         // Check if result is non-negative and fits in a smi.
         __ testl(rax, Immediate(0xc0000000));
         __ j(not_zero, &non_smi_result);
       } else {
         // Check if result fits in a smi.
         __ cmpl(rax, Immediate(0xc0000000));
         __ j(negative, &non_smi_result);
@@ skipping 105 matching lines @@
 int CompareStub::MinorKey() {
   // Encode the two parameters in a unique 16 bit value.
   ASSERT(static_cast<unsigned>(cc_) < (1 << 15));
   return (static_cast<unsigned>(cc_) << 1) | (strict_ ? 1 : 0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal