Do not transform a/b into a * (1/b) in the parser for integer constants....

src/parser.cc

Index: src/parser.cc
===================================================================
--- src/parser.cc	(revision 6162)
+++ src/parser.cc	(working copy)
@@ -2323,26 +2323,6 @@
         }
       }
 
-      // Convert constant divisions to multiplications for speed.
-      if (op == Token::DIV &&
-          y && y->AsLiteral() && y->AsLiteral()->handle()->IsNumber()) {
-        double y_val = y->AsLiteral()->handle()->Number();
-        int64_t y_int = static_cast<int64_t>(y_val);
-        // There are rounding issues with this optimization, but they don't
-        // apply if the number to be divided with has a reciprocal that can be
-        // precisely represented as a floating point number.  This is the case
-        // if the number is an integer power of 2.  Negative integer powers of
-        // 2 work too, but for -2, -1, 1 and 2 we don't do the strength
-        // reduction because the inlined optimistic idiv has a reasonable
-        // chance of succeeding by producing a Smi answer with no remainder.
-        if (static_cast<double>(y_int) == y_val &&
-            (IsPowerOf2(y_int) || IsPowerOf2(-y_int)) &&
-            (y_int > 2 || y_int < -2)) {
-          y = NewNumberLiteral(1 / y_val);
-          op = Token::MUL;
-        }
-      }
-
       // For now we distinguish between comparisons and other binary
       // operations.  (We could combine the two and get rid of this
       // code and AST node eventually.)