We should call UsesBeforeIonRecompile() instead of using js_IonOptions.usesBeforeCompile. Problem with the latter is that we can Ion-compile large scripts too eagerly when called from the interpreter/VM. This seems to win 1000 points or so on Octane-mandreel. It fixes an issue where a pretty big Ion script is immediately invalidated when it runs due to incomplete type information for the non-OSR entry point. Hannes, I think this also affects bug 939614.

Comment on attachment 8341271 [details] [diff] [review] Patch Review of attachment 8341271 [details] [diff] [review]: ----------------------------------------------------------------- I already wondered why we used different tests for checking IonCompile is ready to compile or when baseline decides when to compile. But at the time I reasoned this wouldn't occur. But indeed a very cold script (usecount < 10) calling such a problem case script will not use the right usecount. Good find!