Disable speculative LICM when it may lead to unnecessary deopts

test/mjsunit/regress/regress-2250.js

 // Copyright 2012 the V8 project authors. All rights reserved.
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 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Flags: --allow-natives-syntax
 
-var uint8 = new Uint8Array(1);
+// The original problem from the bug: In the example below SMI check for b
+// generated for inlining of equals invocation (marked with (*)) will be hoisted
+// out of the loop across the typeof b === "object" condition and cause an
+// immediate deopt. Another problem here is that no matter how many time we
+// deopt and reopt we will continue to produce the wrong code.
+//
+// The fix is to notice when a deopt and subsequent reopt doesn't find
+// additional type information, indicating that optimistic LICM should be
+// disabled during compilation.
+
+function eq(a, b) {
+  if (typeof b === "object") {
+    return b.equals(a);  // (*)
+  }
+  return a === b;
+}
+
+Object.prototype.equals = function (other) {
+  return (this === other);
+};
 
 function test() {
-  uint8[0] = 0x800000aa;
-  assertEquals(0xaa, uint8[0]);
+  for (var i = 0; !eq(i, 10); i++)
+    ;
 }
 
-test();
-test();
+eq({}, {});
+eq({}, {});
+eq(1, 1);
+eq(1, 1);
 test();
 %OptimizeFunctionOnNextCall(test);
 test();
+%OptimizeFunctionOnNextCall(test);
+// Second compilation should have noticed that LICM wasn't a good idea, and now
+// function should no longer deopt when called.
+test();
+assertTrue(2 != %GetOptimizationStatus(test));
 
-var uint32 = new Uint32Array(1);
-
-function test2() {
-  uint32[0] = 0x80123456789abcde;
-  assertEquals(0x789ac000, uint32[0]);
-}
-
-test2();
-test2();
-%OptimizeFunctionOnNextCall(test2);
-test2();