MIPS: Optimise Math.floor(x/y) to use integer division for MIPS.

test/mjsunit/math-floor-of-div.js

 // Copyright 2012 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
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 //
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@@ skipping 77 matching lines @@
     assertEquals(Math.floor(div(k,  18)), Math.floor(k /  18));
     assertEquals(Math.floor(div(k,  -18)), Math.floor(k /  -18));
     assertEquals(Math.floor(div(k,  19)), Math.floor(k /  19));
     assertEquals(Math.floor(div(k,  -19)), Math.floor(k /  -19));
     assertEquals(Math.floor(div(k,  20)), Math.floor(k /  20));
     assertEquals(Math.floor(div(k,  -20)), Math.floor(k /  -20));
     assertEquals(Math.floor(div(k,  21)), Math.floor(k /  21));
     assertEquals(Math.floor(div(k,  -21)), Math.floor(k /  -21));
     assertEquals(Math.floor(div(k,  22)), Math.floor(k /  22));
     assertEquals(Math.floor(div(k,  -22)), Math.floor(k /  -22));
-    assertEquals(Math.floor(div(k,  23)), Math.floor(k /  23));
+    assertEquals(Math.floor(div(k,  13)), Math.floor(k /  13));

[danno, 2013/02/11 15:30:50]

Why this change?

[palfia, 2013/05/09 22:50:09]

This change is not needed, removed.

     assertEquals(Math.floor(div(k,  -23)), Math.floor(k /  -23));
     assertEquals(Math.floor(div(k,  24)), Math.floor(k /  24));
     assertEquals(Math.floor(div(k,  -24)), Math.floor(k /  -24));
     assertEquals(Math.floor(div(k,  25)), Math.floor(k /  25));
     assertEquals(Math.floor(div(k,  -25)), Math.floor(k /  -25));
     assertEquals(Math.floor(div(k, 125)), Math.floor(k / 125));
     assertEquals(Math.floor(div(k, -125)), Math.floor(k / -125));
     assertEquals(Math.floor(div(k, 625)), Math.floor(k / 625));
     assertEquals(Math.floor(div(k, -625)), Math.floor(k / -625));
   }
@@ skipping 170 matching lines @@
 
 test_div_deopt_minus_zero_v();
 test_div_deopt_overflow_v();
 test_div_deopt_div_by_zero_v();
 %OptimizeFunctionOnNextCall(test_div_deopt_minus_zero_v);
 %OptimizeFunctionOnNextCall(test_div_deopt_overflow_v);
 %OptimizeFunctionOnNextCall(test_div_deopt_div_by_zero_v);
 test_div_deopt_minus_zero_v();
 test_div_deopt_overflow_v();
 test_div_deopt_div_by_zero_v();