Faster 64-bit right-shift for the ia32 compiler.

runtime/vm/flow_graph_optimizer.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/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 130 matching lines @@
 
 void FlowGraphOptimizer::SelectRepresentations() {
   // Convervatively unbox all phis that were proven to be of type Double.
   for (intptr_t i = 0; i < block_order_.length(); ++i) {
     JoinEntryInstr* join_entry = block_order_[i]->AsJoinEntry();
     if (join_entry == NULL) continue;
 
     if (join_entry->phis() != NULL) {
       for (intptr_t i = 0; i < join_entry->phis()->length(); ++i) {
         PhiInstr* phi = (*join_entry->phis())[i];
-        if ((phi != NULL) && (phi->GetPropagatedCid() == kDoubleCid)) {
+        if (phi == NULL) continue;
+        if (phi->GetPropagatedCid() == kDoubleCid) {
           phi->set_representation(kUnboxedDouble);
         }
       }
     }
   }
 
   // Process all instructions and insert conversions where needed.
   GraphEntryInstr* graph_entry = block_order_[0]->AsGraphEntry();
 
   // Visit incoming parameters and constants.
@@ skipping 351 matching lines @@
     case Token::kBIT_XOR:
       if (HasOnlyTwoSmi(ic_data)) {
         operands_type = kSmiCid;
       } else if (HasTwoMintOrSmi(ic_data) &&
                  FlowGraphCompiler::SupportsUnboxedMints()) {
         operands_type = kMintCid;
       } else {
         return false;
       }
       break;
+    case Token::kSHR:
+      if (HasOnlyTwoSmi(ic_data)) {

[Kevin Millikin (Google), 2012/10/05 12:52:58]

Should really be ...TwoSmis.

[Florian Schneider, 2012/10/05 14:40:31]

Done.

+        operands_type = kSmiCid;
+      } else if (HasTwoMintOrSmi(ic_data) &&
+                 FlowGraphCompiler::SupportsUnboxedMints()) {
+        operands_type = kMintCid;
+      } else {
+        return false;
+      }
+      break;
     case Token::kTRUNCDIV:
-    case Token::kSHR:
     case Token::kSHL:
       if (HasOnlyTwoSmi(ic_data)) {
         operands_type = kSmiCid;
       } else {
         return false;
       }
       break;
     default:
       UNREACHABLE();
   };
@@ skipping 12 matching lines @@
                  call->env(),
                  Definition::kEffect);
 
     BinaryDoubleOpInstr* double_bin_op =
         new BinaryDoubleOpInstr(op_kind, left->Copy(), right->Copy(), call);
     call->ReplaceWith(double_bin_op, current_iterator());
     RemovePushArguments(call);
   } else if (operands_type == kMintCid) {
     Value* left = call->ArgumentAt(0)->value();
     Value* right = call->ArgumentAt(1)->value();
-    BinaryMintOpInstr* bin_op =
-        new BinaryMintOpInstr(op_kind, left, right, call);
-    call->ReplaceWith(bin_op, current_iterator());
+    if (op_kind == Token::kSHR) {
+      ShiftMintOpInstr* shift_op =
+          new ShiftMintOpInstr(op_kind, left, right, call);
+      call->ReplaceWith(shift_op, current_iterator());
+    } else {
+      BinaryMintOpInstr* bin_op =
+          new BinaryMintOpInstr(op_kind, left, right, call);
+      call->ReplaceWith(bin_op, current_iterator());
+    }
     RemovePushArguments(call);
   } else if (op_kind == Token::kMOD) {
     // TODO(vegorov): implement fast path code for modulo.
     ASSERT(operands_type == kSmiCid);
     if (!call->ArgumentAt(1)->value()->BindsToConstant()) return false;
     const Object& obj = call->ArgumentAt(1)->value()->BoundConstant();
     if (!obj.IsSmi()) return false;
     const intptr_t value = Smi::Cast(obj).Value();
     if ((value > 0) && Utils::IsPowerOfTwo(value)) {
       Value* left = call->ArgumentAt(0)->value();
@@ skipping 2406 matching lines @@
 }
 
 
 void ConstantPropagator::VisitBinaryMintOp(
     BinaryMintOpInstr* instr) {
   // TODO(kmillikin): Handle binary operations.
   SetValue(instr, non_constant_);
 }
 
 
+void ConstantPropagator::VisitShiftMintOp(
+    ShiftMintOpInstr* instr) {
+  // TODO(kmillikin): Handle shift operations.
+  SetValue(instr, non_constant_);
+}
+
+
 void ConstantPropagator::VisitUnaryMintOp(
     UnaryMintOpInstr* instr) {
   // TODO(kmillikin): Handle unary operations.
   SetValue(instr, non_constant_);
 }
 
 
 void ConstantPropagator::VisitUnarySmiOp(UnarySmiOpInstr* instr) {
   const Object& value = instr->value()->definition()->constant_value();
   if (IsNonConstant(value)) {
@@ skipping 230 matching lines @@
 
   if (FLAG_trace_constant_propagation) {
     OS::Print("\n==== After constant propagation ====\n");
     FlowGraphPrinter printer(*graph_);
     printer.PrintBlocks();
   }
 }
 
 
 }  // namespace dart