Add DoubleToSmi optimistically, preventing boxing/unboxing of doubles and propagate smi-nessof the …

runtime/vm/intermediate_language_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.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/intermediate_language.h"
 
 #include "lib/error.h"
@@ skipping 2297 matching lines @@
   compiler->GenerateStaticCall(instance_call()->deopt_id(),
                                instance_call()->token_pos(),
                                target,
                                kNumberOfArguments,
                                Array::Handle(),  // No argument names.,
                                locs());
   __ Bind(&done);
 }
 
 
+LocationSummary* DoubleToSmiInstr::MakeLocationSummary() const {
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* result = new LocationSummary(
+      kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  result->set_in(0, Location::RequiresXmmRegister());
+  result->set_out(Location:: Location::RequiresRegister());
+  return result;
+}
+
+
+void DoubleToSmiInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Label* deopt = compiler->AddDeoptStub(deopt_id(), kDeoptDoubleToSmi);
+  Register result = locs()->out().reg();
+  XmmRegister value = locs()->in(0).xmm_reg();
+  __ cvttsd2si(result, value);

[Vyacheslav Egorov (Google), 2012/12/17 12:53:44]

This code is almost exactly repeating code in the Intrinsifier::Double_toInt. 

I hope we will find a way to remove this duplication soon.

[srdjan, 2012/12/18 00:12:47]

Code duplication of short patterns is OK. I think it is more readable and
actually easier to maintain, than calling a 'macro' assembler function that does
something.

[Vyacheslav Egorov (Google), 2012/12/18 11:45:10]

Well, the discrepancy in x64 demonstrates that it is not easier to maintain at
all. However at the moment I see no easy alternative. 

+  // Overflow is signalled with minint.
+  Label do_call, done;
+  // Check for overflow and that it fits into Smi.
+  __ cmpl(result, Immediate(0xC0000000));
+  __ j(NEGATIVE, deopt);
+  __ SmiTag(result);
+}
+
+
 LocationSummary* PolymorphicInstanceCallInstr::MakeLocationSummary() const {
   return MakeCallSummary();
 }
 
 
 void PolymorphicInstanceCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Label* deopt = compiler->AddDeoptStub(instance_call()->deopt_id(),
                                         kDeoptPolymorphicInstanceCallTestFail);
   if (ic_data().NumberOfChecks() == 0) {
     __ jmp(deopt);
@@ skipping 464 matching lines @@
   __ pcmpeqq(XMM0, XMM0);  // Generate all 1's.
   __ pxor(value, XMM0);
 }
 
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64