VM: Intrinsify double arithmetic operations with a smi rhs.

runtime/vm/intrinsifier_ia32.cc

Index: runtime/vm/intrinsifier_ia32.cc
diff --git a/runtime/vm/intrinsifier_ia32.cc b/runtime/vm/intrinsifier_ia32.cc
index 4e2a8e9f34136f7c39aa396f8ce09c303d8e95e4..44dd318073f8b05c216b91d3fa41994dc42e395a 100644
--- a/runtime/vm/intrinsifier_ia32.cc
+++ b/runtime/vm/intrinsifier_ia32.cc
@@ -1441,10 +1441,11 @@ void Intrinsifier::Double_lessEqualThan(Assembler* assembler) {
 // Expects left argument to be double (receiver). Right argument is unknown.
 // Both arguments are on stack.
 static void DoubleArithmeticOperations(Assembler* assembler, Token::Kind kind) {
-  Label fall_through;
-  TestLastArgumentIsDouble(assembler, &fall_through, &fall_through);
+  Label fall_through, is_smi, double_op;
+  TestLastArgumentIsDouble(assembler, &is_smi, &fall_through);
   // Both arguments are double, right operand is in EAX.
   __ movsd(XMM1, FieldAddress(EAX, Double::value_offset()));
+  __ Bind(&double_op);
   __ movl(EAX, Address(ESP, + 2 * kWordSize));  // Left argument.
   __ movsd(XMM0, FieldAddress(EAX, Double::value_offset()));
   switch (kind) {
@@ -1463,6 +1464,10 @@ static void DoubleArithmeticOperations(Assembler* assembler, Token::Kind kind) {
                  EBX);
   __ movsd(FieldAddress(EAX, Double::value_offset()), XMM0);
   __ ret();
+  __ Bind(&is_smi);
+  __ SmiUntag(EAX);
+  __ cvtsi2sd(XMM1, EAX);
+  __ jmp(&double_op);
   __ Bind(&fall_through);
 }