C++ Interpreter

[steve goldman]

Volker Simonis wrote:
>
> 
> Hi Steve,
> 
> thank you for the assistence. Although your fix helps a little, the
> Interpreter dosn't run much further. After applying the fix, I got an
> assertion, which claims that the last_Java_sp is biased:
> 
> #  Internal Error
> (/sapmnt/us4312/a/priv/d046063/p4/bas2/j2se/17_adapted/control/sap/../../hotspot/src/cpu/sparc/vm/javaFrameAnchor_sparc.hpp:90),
> pid=3756, tid=2
> #  Error: assert(((intptr_t)_last_Java_sp & 0xF) == 0,"Biased last_Java_sp")
> 
> However I dont think that the last_Java_SP is really biased. It seems
> that it is just not 16-byte aligned as expected, because it's value at
> the assertion point is 0x7adfe8a8. If it would be really biased, it
> should have an odd value, right?

Yep. I suspect in the ages since 64bit sparc ran it has had lots of bit 
rot. I'll look at getting it going but it isn't likely to be too soon.


> After your 'encouraging words' about the state of the C++ Interpreter,
> I tried a 32 bit build and it built and ran. So this seems to be yet
> another 64 bit problem. Any idea what's wrong now?

I suspect that the frame manager isn't doing proper alignment of the 
stack it is creating.

> 
> I also tried a 32 bit build on Linux/Intel. The debug build succeeded
> (and ran) out of the box, but the opt had some problems because of an
> error in the labels array  " opclabels_data" in
> bytecodeInterpreter.cpp. Attached you can find a patch that solves the
> problem. So at least on Linux/x86 the C++ Interpreter seems to be
> usabel (i.e. it runs JVM98 with -Xint).
> 
> What about the defects detected so far (the fix supplied by you and
> the patch for bytecodeInterpreter.cpp). Would you be so kind to open a
> Java bug report or should I do this myself?

I'll open a bug and work on getting them fixed. It will be a while 
(weeks) as the workspace situation is about to get quite interesting 
around here as we are switching from teamware to mercurial very shortly 
and my "real" work does have higher priority.

-- 
Steve