Propagate representation: anything*double => double; -double => double

src/hydrogen.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6172 matching lines @@
   HValue* context = environment()->LookupContext();
   HInstruction* instr =
       new(zone()) HMul(context, value, graph_->GetConstantMinus1());
   TypeInfo info = oracle()->UnaryType(expr);
   if (info.IsUninitialized()) {
     AddInstruction(new(zone()) HSoftDeoptimize);
     current_block()->MarkAsDeoptimizing();
     info = TypeInfo::Unknown();
   }
   Representation rep = ToRepresentation(info);
+  if (value->representation().IsDouble()) {
+    rep = Representation::Double();
+  }
   TraceRepresentation(expr->op(), info, instr, rep);
   instr->AssumeRepresentation(rep);
   return ast_context()->ReturnInstruction(instr, expr->id());
 }
 
 
 void HGraphBuilder::VisitBitNot(UnaryOperation* expr) {
   CHECK_ALIVE(VisitForValue(expr->expression()));
   HValue* value = Pop();
   TypeInfo info = oracle()->UnaryType(expr);
@@ skipping 312 matching lines @@
   if (info.IsSmi() &&
       ((left->IsConstant() && HConstant::cast(left)->HasStringValue()) ||
        (right->IsConstant() && HConstant::cast(right)->HasStringValue()))) {
     return instr;
   }
   Representation rep = ToRepresentation(info);
   // We only generate either int32 or generic tagged bitwise operations.
   if (instr->IsBitwiseBinaryOperation() && rep.IsDouble()) {
     rep = Representation::Integer32();
   }
+  if (expr->op() == Token::MUL &&
+      (left->representation().IsDouble() ||
+       right->representation().IsDouble())) {
+    rep = Representation::Double();
+  }
   TraceRepresentation(expr->op(), info, instr, rep);
   instr->AssumeRepresentation(rep);
   return instr;
 }
 
 
 // Check for the form (%_ClassOf(foo) === 'BarClass').
 static bool IsClassOfTest(CompareOperation* expr) {
   if (expr->op() != Token::EQ_STRICT) return false;
   CallRuntime* call = expr->left()->AsCallRuntime();
@@ skipping 1630 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal