Request for reviews (XS): 6876037: CTW fails jdk7/hotspot/src/share/vm/opto/type.cpp:2055. assert(bits,"Use TypePtr for NULL")

[Vladimir Kozlov]

Thank you, Tom

Vladimir

Tom Rodriguez wrote:
> Looks ok.
> 
> tom
> 
> On Jan 5, 2011, at 4:17 PM, Vladimir Kozlov wrote:
> 
>> http://cr.openjdk.java.net/~kvn/6876037/webrev
>>
>> Fixed 6876037: CTW fails jdk7/hotspot/src/share/vm/opto/type.cpp:2055. assert(bits,"Use TypePtr for NULL")
>>
>> Missing 0 value check in TypeRawPtr::add_offset().
>>
>> CastX2P node in address expression for unsafe memory operation
>> AddP(top, (CastX2P(SubI(3, loop_phi)), long) transformed into
>> AddP(top, ConP#3, SubI(0, loop_phi)):
>>
>> for (int idx = 0; idx < 4; idx++) {
>>  unsafe.putByte(bufptr + (3-idx), b);
>>
>> After loop full unroll this expression transformed
>> into AddP(top, ConP#3, -3). We hit assert during type
>> calculation for this node.
>