X64: Use roundsd for DoMathFloor.

test/mjsunit/math-round.js

 // Copyright 2010 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 14 matching lines @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Flags: --allow-natives-syntax
 
 function testRound(expect, input) {
   function doRound(input) {
     return Math.round(input);
   }
   assertEquals(expect, doRound(input));
+  assertEquals(expect, doRound(input));
+  assertEquals(expect, doRound(input));
   %OptimizeFunctionOnNextCall(doRound);
   assertEquals(expect, doRound(input));
 }
 
 testRound(0, 0);
 testRound(-0, -0);
 testRound(Infinity, Infinity);
 testRound(-Infinity, -Infinity);
 testRound(NaN, NaN);
 
@@ skipping 101 matching lines @@
 testRound(-Math.pow(2,52)+1, -max_fraction);
 testRound(-min_nonfraction, -min_nonfraction);
 testRound(-max_non_infinite, -max_non_infinite);
 
 testRound(min_smi31, min_smi31 - 0.5);
 testRound(min_smi31 + 1, min_smi31 + 0.5);
 testRound(min_smi32, min_smi32 - 0.5);
 testRound(min_smi32 + 1, min_smi32 + 0.5);