Reland "Add DoubleTestOp instruction"

runtime/vm/intrinsifier_ia32.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // The intrinsic code below is executed before a method has built its frame.
 // The return address is on the stack and the arguments below it.
 // Registers EDX (arguments descriptor) and ECX (function) must be preserved.
 // Each intrinsification method returns true if the corresponding
 // Dart method was intrinsified.
 
@@ skipping 1548 matching lines @@
   __ comisd(XMM0, XMM0);
   __ j(PARITY_EVEN, &is_true, Assembler::kNearJump);  // NaN -> true;
   __ LoadObject(EAX, Bool::False());
   __ ret();
   __ Bind(&is_true);
   __ LoadObject(EAX, Bool::True());
   __ ret();
 }
 
 
+void Intrinsifier::Double_getIsInfinite(Assembler* assembler) {
+  Label not_inf;
+  __ movl(EAX, Address(ESP, +1 * kWordSize));
+  __ movl(EBX, FieldAddress(EAX, Double::value_offset()));
+
+  // If the low word isn't zero, then it isn't infinity.
+  __ cmpl(EBX, Immediate(0));
+  __ j(NOT_EQUAL, &not_inf, Assembler::kNearJump);
+  // Check the high word.
+  __ movl(EBX, FieldAddress(EAX, Double::value_offset() + kWordSize));
+  // Mask off sign bit.
+  __ andl(EBX, Immediate(0x7FFFFFFF));
+  // Compare with +infinity.
+  __ cmpl(EBX, Immediate(0x7FF00000));
+  __ j(NOT_EQUAL, &not_inf, Assembler::kNearJump);
+  __ LoadObject(EAX, Bool::True());
+  __ ret();
+
+  __ Bind(&not_inf);
+  __ LoadObject(EAX, Bool::False());
+  __ ret();
+}
+
+
 void Intrinsifier::Double_getIsNegative(Assembler* assembler) {
   Label is_false, is_true, is_zero;
   __ movl(EAX, Address(ESP, +1 * kWordSize));
   __ movsd(XMM0, FieldAddress(EAX, Double::value_offset()));
   __ xorpd(XMM1, XMM1);  // 0.0 -> XMM1.
   __ comisd(XMM0, XMM1);
   __ j(PARITY_EVEN, &is_false, Assembler::kNearJump);  // NaN -> false.
   __ j(EQUAL, &is_zero, Assembler::kNearJump);  // Check for negative zero.
   __ j(ABOVE_EQUAL, &is_false, Assembler::kNearJump);  // >= 0 -> false.
   __ Bind(&is_true);
@@ skipping 575 matching lines @@
   __ Bind(&true_label);
   __ LoadObject(EAX, Bool::True());
   __ ret();
 }
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32