Inline toDouble calls on mints

runtime/vm/flow_graph_optimizer.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.
 
 #include "vm/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
@@ skipping 45 matching lines @@
 static bool ShouldInlineSimd() {
   return FlowGraphCompiler::SupportsUnboxedSimd128();
 }
 
 
 static bool CanUnboxDouble() {
   return FlowGraphCompiler::SupportsUnboxedDoubles();
 }
 
 
+static bool CanConvertUnboxedMintToDouble() {
+#if defined(TARGET_ARCH_IA32)
+  return true;
+#else

[Florian Schneider, 2014/09/19 09:49:00]

I think there should be a TODO for the other platforms that have unboxed mints.

[Cutch, 2014/09/19 16:17:41]

Added a note about ARM and a TODO to check for MIPS.

+  return false;
+#endif
+}
+
 // Optimize instance calls using ICData.
 void FlowGraphOptimizer::ApplyICData() {
   VisitBlocks();
 }
 
 
 // Optimize instance calls using cid.  This is called after optimizer
 // converted instance calls to instructions. Any remaining
 // instance calls are either megamorphic calls, cannot be optimized or
 // have no runtime type feedback collected.
@@ skipping 554 matching lines @@
         deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
     converted = new UnboxInt32Instr(use->CopyWithType(), deopt_id);
   } else if ((from == kUnboxedInt32) && (to == kTagged)) {
     converted = new BoxInt32Instr(use->CopyWithType());
   } else if ((from == kTagged) && (to == kUnboxedUint32)) {
     const intptr_t deopt_id = (deopt_target != NULL) ?
         deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
     converted = new UnboxUint32Instr(use->CopyWithType(), deopt_id);
   } else if (from == kUnboxedMint && to == kUnboxedDouble) {
     ASSERT(CanUnboxDouble());
-    // Convert by boxing/unboxing.
-    // TODO(fschneider): Implement direct unboxed mint-to-double conversion.
-    BoxIntegerInstr* boxed =
-        new(I) BoxIntegerInstr(use->CopyWithType());
-    use->BindTo(boxed);
-    InsertBefore(insert_before, boxed, NULL, FlowGraph::kValue);
-
     const intptr_t deopt_id = (deopt_target != NULL) ?
         deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
-    converted = new(I) UnboxDoubleInstr(new(I) Value(boxed), deopt_id);
-
+    if (CanConvertUnboxedMintToDouble()) {
+      // Fast path.
+      converted = new MintToDoubleInstr(use->CopyWithType(), deopt_id);
+    } else {
+      // Slow path.
+      BoxIntegerInstr* boxed = new(I) BoxIntegerInstr(use->CopyWithType());
+      use->BindTo(boxed);
+      InsertBefore(insert_before, boxed, NULL, FlowGraph::kValue);
+      converted = new(I) UnboxDoubleInstr(new(I) Value(boxed), deopt_id);
+    }
   } else if ((from == kUnboxedDouble) && (to == kTagged)) {
     ASSERT(CanUnboxDouble());
     converted = new(I) BoxDoubleInstr(use->CopyWithType());
-
   } else if ((from == kTagged) && (to == kUnboxedDouble)) {
     ASSERT(CanUnboxDouble());
     ASSERT((deopt_target != NULL) ||
            (use->Type()->ToCid() == kDoubleCid));
     const intptr_t deopt_id = (deopt_target != NULL) ?
         deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
     ConstantInstr* constant = use->definition()->AsConstant();
     if ((constant != NULL) && constant->value().IsSmi()) {
       const double dbl_val = Smi::Cast(constant->value()).AsDoubleValue();
       const Double& dbl_obj =
@@ skipping 2379 matching lines @@
           call->deopt_id(),
           call->token_pos());
       ReplaceCall(call, store_op);
       return true;
     }
     return false;
   }
 
   if (CanUnboxDouble() &&
       (recognized_kind == MethodRecognizer::kIntegerToDouble) &&
-      (ic_data.NumberOfChecks() == 1) &&
-      (class_ids[0] == kSmiCid)) {
-    AddReceiverCheck(call);
-    ReplaceCall(call,
-                new(I) SmiToDoubleInstr(
-                    new(I) Value(call->ArgumentAt(0)),
-                    call->token_pos()));
-    return true;
+      (ic_data.NumberOfChecks() == 1)) {
+    if (class_ids[0] == kSmiCid) {
+      AddReceiverCheck(call);
+      ReplaceCall(call,
+                  new(I) SmiToDoubleInstr(
+                      new(I) Value(call->ArgumentAt(0)),
+                      call->token_pos()));
+      return true;
+    } else if ((class_ids[0] == kMintCid) && CanConvertUnboxedMintToDouble()) {
+      AddReceiverCheck(call);
+      ReplaceCall(call,
+                  new(I) MintToDoubleInstr(new(I) Value(call->ArgumentAt(0)),
+                                           call->deopt_id()));
+      return true;
+    }
   }
 
   if (class_ids[0] == kDoubleCid) {
     if (!CanUnboxDouble()) {
       return false;
     }
     switch (recognized_kind) {
       case MethodRecognizer::kDoubleToInteger: {
         AddReceiverCheck(call);
         ASSERT(call->HasICData());
@@ skipping 1425 matching lines @@
     }
     InvokeMathCFunctionInstr* invoke =
         new(I) InvokeMathCFunctionInstr(args,
                                         call->deopt_id(),
                                         recognized_kind,
                                         call->token_pos());
     ReplaceCall(call, invoke);
   } else if (recognized_kind == MethodRecognizer::kDoubleFromInteger) {
     if (call->HasICData() && (call->ic_data()->NumberOfChecks() == 1)) {
       const ICData& ic_data = *call->ic_data();
-      if (CanUnboxDouble() && ArgIsAlways(kSmiCid, ic_data, 0)) {
-        Definition* arg = call->ArgumentAt(0);
-        InsertBefore(call,
-                     new(I) CheckSmiInstr(
-                         new(I) Value(arg),
-                         call->deopt_id(),
-                         call->token_pos()),
-                     call->env(),
-                     FlowGraph::kEffect);
-        ReplaceCall(call,
-                    new(I) SmiToDoubleInstr(new(I) Value(arg),
-                                            call->token_pos()));
+      if (CanUnboxDouble()) {
+        if (ArgIsAlways(kSmiCid, ic_data, 1)) {
+          Definition* arg = call->ArgumentAt(1);
+          AddCheckSmi(arg, call->deopt_id(), call->env(), call);
+          ReplaceCall(call,
+                      new(I) SmiToDoubleInstr(new(I) Value(arg),
+                                              call->token_pos()));
+        } else if (ArgIsAlways(kMintCid, ic_data, 1) &&
+                   CanConvertUnboxedMintToDouble()) {
+          Definition* arg = call->ArgumentAt(1);
+          ReplaceCall(call,
+                      new(I) MintToDoubleInstr(new(I) Value(arg),
+                                               call->deopt_id()));
+        }
       }
     }
   } else if (call->function().IsFactory()) {
     const Class& function_class =
         Class::Handle(I, call->function().Owner());
     if ((function_class.library() == Library::CoreLibrary()) ||
         (function_class.library() == Library::TypedDataLibrary())) {
       intptr_t cid = FactoryRecognizer::ResultCid(call->function());
       switch (cid) {
         case kArrayCid: {
@@ skipping 3888 matching lines @@
   const Object& value = instr->value()->definition()->constant_value();
   if (IsConstant(value) && value.IsInteger()) {
     SetValue(instr, Double::Handle(I,
         Double::New(Integer::Cast(value).AsDoubleValue(), Heap::kOld)));
   } else if (IsNonConstant(value)) {
     SetValue(instr, non_constant_);
   }
 }
 
 
+void ConstantPropagator::VisitMintToDouble(MintToDoubleInstr* instr) {
+  const Object& value = instr->value()->definition()->constant_value();
+  if (IsConstant(value) && value.IsInteger()) {
+    SetValue(instr, Double::Handle(I,
+        Double::New(Integer::Cast(value).AsDoubleValue(), Heap::kOld)));
+  } else if (IsNonConstant(value)) {
+    SetValue(instr, non_constant_);
+  }
+}
+
+
 void ConstantPropagator::VisitInt32ToDouble(Int32ToDoubleInstr* instr) {
   const Object& value = instr->value()->definition()->constant_value();
   if (IsConstant(value) && value.IsInteger()) {
     SetValue(instr, Double::Handle(I,
         Double::New(Integer::Cast(value).AsDoubleValue(), Heap::kOld)));
   } else if (IsNonConstant(value)) {
     SetValue(instr, non_constant_);
   }
 }
 
@@ skipping 1647 matching lines @@
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits_collector_.exits().length(); i++) {
     CreateMaterializationAt(
         exits_collector_.exits()[i], alloc, alloc->cls(), *slots);
   }
 }
 
 
 }  // namespace dart