[9] RFR: 8044538: assert(which != imm_operand) failed: instruction is not a movq reg, imm64

[Christian Thalinger]

On Jun 5, 2014, at 1:33 AM, Tobias Hartmann <tobias.hartmann at oracle.com> wrote:

> Hi Vladimir,
> 
> thanks for the review.
> 
>> Looks good. PrintRelocations flag is used very rare, that is why it rotted. Please, add jreg test (use -XX:+IgnoreUnrecognizedVMOptions). 
> 
> I added a jtreg test to test/compiler/8044538/ that uses -Xcomp and -XX:+PrintRecolations. It fails without my changes.

We are trying to not use bug id directories anymore.  Please move the test to a more meaningful directory with a meaningful name.

> 
> New webrev: http://cr.openjdk.java.net/~thartmann/8044538/webrev.01/
> 
>> Since this debug flag almost never used backporting the fix only into 8u may be enough.
> 
> Okay.
> 
> Thanks,
> Tobias
> 
>> 
>> Thanks,
>> Vladimir
>> 
>> On 6/4/14 1:30 AM, Tobias Hartmann wrote:
>>> Hi,
>>> 
>>> please review the following patch for bug 8044538.
>>> 
>>> *Problem*
>>> Executing a debug build of HotSpot with the flags -XX:+PrintRelocations
>>> -Xcomp hits a ShouldNotReachHere() or an assert in
>>> Assembler::locate_operand(..) stating that the instruction for which we
>>> try to find the operand is not valid.
>>> 
>>> The problem occurs while printing the relocation entries for a C2
>>> compiled function. The C2 compiler adds internal_word_type relocations
>>> for the jump table entries in the constant section of a method (see
>>> Compile::ConstantTable::fill_jump_table(...)). These relocations are
>>> processed by RelocIterator::print_current(...) and
>>> internal_word_Relocation::target().
>>> Relocation::pd_get_address_from_code() then tries to retrieve the
>>> address from an instruction but fails because the relocation points into
>>> the constant section only containing the target address.
>>> 
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8044538
>>> 
>>> *Solution*
>>> The implementation of internal_word_Relocation::target() is changed to
>>> check if the relocation points into the constant section and if so
>>> directly returns the target address instead of trying to retrieve it
>>> from an instruction. The same is already done in
>>> internal_word_Relocation::fix_relocation_after_move(..).
>>> 
>>> Webrev: http://cr.openjdk.java.net/~thartmann/8044538/webrev.00/
>>> 
>>> *Tests*
>>> Failing configuration, JPRT
>>> 
>>> Apparently this did not show up for any of our tests. Do we need an
>>> additional test for this?
>>> Since it already fails for JDK 7 and 8. Should we backport the patch?
>>> 
>>> Thanks,
>>> Tobias
>>> 
>>> 
>