Expand ia32 intrinsic for integer modulo, implement it for x64. Next step will be to emit it direct…

runtime/vm/intrinsifier_ia32.cc

 // Copyright (c) 2012, 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 568 matching lines @@
   __ Bind(&fall_through);
   return false;
 }
 
 
 bool Intrinsifier::Integer_mul(Assembler* assembler) {
   return Integer_mulFromInteger(assembler);
 }
 
 
-// Simple implementation: for positive dividend values greater than divisor,
-// return dividend.
 bool Intrinsifier::Integer_modulo(Assembler* assembler) {
-  Label fall_through, return_zero;
+  Label fall_through, return_zero, try_modulo;
   TestBothArgumentsSmis(assembler, &fall_through);
   // EAX: right argument (divisor)
   // Check if modulo by zero -> exception thrown in main function.
   __ cmpl(EAX, Immediate(0));
   __ j(EQUAL, &fall_through,  Assembler::kNearJump);
   __ movl(EBX, Address(ESP, + 2 * kWordSize));  // Left argument (dividend).
   __ cmpl(EBX, Immediate(0));
   __ j(LESS, &fall_through, Assembler::kNearJump);
   __ cmpl(EBX, EAX);
   __ j(EQUAL, &return_zero, Assembler::kNearJump);
-  __ j(GREATER, &fall_through, Assembler::kNearJump);
-  __ movl(EAX, EBX);  // Return dividend.
+  __ j(GREATER, &try_modulo, Assembler::kNearJump);
+  __ movl(EAX, EBX);  // Return dividend as it is smaller than divisor.
   __ ret();
   __ Bind(&return_zero);
   __ xorl(EAX, EAX);  // Return zero.
   __ ret();
+  __ Bind(&try_modulo);
+  // EAX: right (non-null divisor).
+  __ movl(EBX, EAX);
+  __ SmiUntag(EBX);
+  __ movl(EAX, Address(ESP, + 2 * kWordSize));  // Left argument (dividend).
+  __ SmiUntag(EAX);
+  __ cdq();
+  __ idivl(EBX);
+  __ movl(EAX, EDX);
+  __ SmiTag(EAX);
+  __ ret();
   __ Bind(&fall_through);
   return false;
 }
 
 
 bool Intrinsifier::Integer_truncDivide(Assembler* assembler) {
   Label fall_through;
   TestBothArgumentsSmis(assembler, &fall_through);
   // EAX: right argument (divisor)
   __ cmpl(EAX, Immediate(0));
@@ skipping 736 matching lines @@
   __ Bind(&is_true);
   __ LoadObject(EAX, bool_true);
   __ ret();
   return true;
 }
 
 #undef __
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32