Implement flooring division by a constant via truncating division by a constant.

src/hydrogen-instructions.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 1815 matching lines @@
     Range* a = left()->range();
     Range* b = right()->range();
     Range* result = new(zone) Range();
     result->set_can_be_minus_zero(!CheckFlag(kAllUsesTruncatingToInt32) &&
                                   (a->CanBeMinusZero() ||
                                    (a->CanBeZero() && b->CanBeNegative())));
     if (!a->Includes(kMinInt)) {
       ClearFlag(kLeftCanBeMinInt);
     }
 
+    if (!a->CanBeNegative()) {
+      ClearFlag(HValue::kLeftCanBeNegative);
+    }
+
+    if (!a->CanBePositive()) {
+      ClearFlag(HValue::kLeftCanBePositive);
+    }
+
     if (!a->Includes(kMinInt) || !b->Includes(-1)) {
       ClearFlag(kCanOverflow);
     }
 
     if (!b->CanBeZero()) {
       ClearFlag(kCanBeDivByZero);
     }
     return result;
   } else {
     return HValue::InferRange(zone);
@@ skipping 2733 matching lines @@
       break;
     case kExternalMemory:
       stream->Add("[external-memory]");
       break;
   }
 
   stream->Add("@%d", offset());
 }
 
 } }  // namespace v8::internal