On Fri, Apr 22, 2011 at 2:39 AM, Laurent Desnogues <laurent.desnog...@gmail.com> wrote: > On Thu, Apr 21, 2011 at 9:45 PM, Igor Kovalenko > <igor.v.kovale...@gmail.com> wrote: >> On Thu, Apr 21, 2011 at 7:44 PM, Laurent Desnogues >> <laurent.desnog...@gmail.com> wrote: >>> On Thu, Apr 21, 2011 at 4:57 PM, Artyom Tarasenko <atar4q...@gmail.com> >>> wrote: >>>> On Tue, Apr 12, 2011 at 4:14 AM, Igor Kovalenko >>>> <igor.v.kovale...@gmail.com> wrote: >>>>>>> Do you have public test case? >>>>>>> It is possible to code this delay slot write test but real issue may >>>>>>> be corruption elsewhere. >>>> >>>> The test case is trivial: it's just the two instructions, branch and wrpr. >>>> >>>>> In theory there could be multiple issues including compiler induced ones. >>>>> I'd prefer to see some kind of reproducible testcase. >>>> >>>> Ok, attached a 40 byte long test (the first 32 bytes are not used and >>>> needed only because the bios entry point is 0x20). >>>> >>>> $ git pull && make && sparc64-softmmu/qemu-system-sparc64 -bios >>>> test-wrpr.bin -nographic >>>> Already up-to-date. >>>> make[1]: Nothing to be done for `all'. >>>> /mnt/terra/projects/vanilla/qemu/tcg/tcg.c:1892: tcg fatal error >>>> Aborted >>> >>> The problem seems to be that wrpr is using a non-local >>> TCG tmp (cpu_tmp0). >> >> Just tried the test case with write to %pil - seems like write itself is OK. >> The issue appears to be with save_state() call since adding save_state >> to %pil case provokes the same tcg abort. > > The problem is that cpu_tmp0, not being a local tmp, doesn't > need to be saved across helper calls. This results in the > TCG "optimizer" getting rid of it even though it's later used. > Look at the log and you'll see what I mean :-)
I'm not very comfortable with tcg yet. Would it be possible to teach optimizer working with delay slots? Or do I look in the wrong place. -- Kind regards, Igor V. Kovalenko