Request for reviews (S): 6711117: Assertion in 64bit server vm (flat != TypePtr::BOTTOM,"cannot alias-analyze an untyped ptr")

[Tom Rodriguez]

The extra load of base can be eliminated too since you moved the check  
for != NULL outside.

I don't understand this addition:

  && phase->type(base)->higher_equal(TypePtr::NOTNULL)

Why does the base need to be NOTNULL?

tom

On Apr 6, 2009, at 3:33 PM, Vladimir Kozlov wrote:

> http://cr.openjdk.java.net/~kvn/6711117/webrev.00
>
> Fixed 6711117: Assertion in 64bit server vm (flat !=  
> TypePtr::BOTTOM,"cannot alias-analyze an untyped ptr")
>
> Problem:
> The assert is triggered by the eliminate AutoBox code which asks
> an alias type of "NULL+off" address type.
> It is caused by the memory node processing during IGVN before
> its control edge which checks the address's nullness is processed.
>
> Solution:
> Delay a memory node transformation if its control on IGVN worklist.
> Delay a memory node transformation if its address on IGVN worklist.
> Execute the eliminate AutoBox code only when the address is not NULL.
> Use replace_node() instead of subsume_node() during macro nodes
> expansion to put users of the old node on IGVN worklist.
>
> Reviewed by:
>
> Fix verified (y/n): y, bug test
>
> Other testing:
> JPRT