Request for reviews (S): 6910484: incorrect integer optimization (loosing and op-r in a given example)

[Tom Rodriguez]

Why does the new test only guard the dividend->in(i) line and not the needs_rounding line?  Shouldn't it guard both?

tom

On Jan 7, 2010, at 5:48 PM, Vladimir Kozlov wrote:

> 
> http://cr.openjdk.java.net/~kvn/6910484/webrev
> 
> Fixed 6910484: incorrect integer optimization (loosing and op-r in a given example)
> 
> Problem:
> After 6667595 changes Div node ideal optimization incorrectly
> removes AND operation if mask is larger then shift:
> 
> (x & -32)/2 incorrectly transformed to x/2
> 
> Solution:
> Remove AND operation only if mask is equal to shift.
> Add regression test.
> 
> Reviewed by:
> 
> Fix verified (y/n): y, test
> 
> Other testing:
> JPRT
>