RFR (XXS): 8079156: 32 bit Java 9-fastdebug hit assertion in client mode with StackShadowPages flag value from 32 to 50
david.holmes at oracle.com
Mon Jul 13 05:34:49 UTC 2015
On 11/07/2015 7:09 AM, gerard ziemski wrote:
> (resending - forgot to include the issue number in the title)
> Hi all,
> Please review this very small fix:
> bug: https://bugs.openjdk.java.net/browse/JDK-8079156
> webrev: http://cr.openjdk.java.net/~gziemski/8079156_rev0
I'd like to hear from the compiler folk about this bug as I'm unclear on
why StackBanging adds to the code buffer, and why this suddenly seems to
be a new problem - did something change? Or have we not exercised the
range of values before?
I'd also like to understand whether the code buffer resizing should be
rounded up (or whether it will be rounded up internally)? e.g. power of
two, multiple of nK for some n etc.
The 112 value seems odd for 50 pages - is this 2 bytes (words?) per page
plus some fixed overhead? Can it be expressed as a function of
StackShadowPages rather than hardwiring to 112 which only works for
values < 50?
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