diff options
Diffstat (limited to 'results/classifier/semantic-bugs/instruction/1916269')
| -rw-r--r-- | results/classifier/semantic-bugs/instruction/1916269 | 70 |
1 files changed, 0 insertions, 70 deletions
diff --git a/results/classifier/semantic-bugs/instruction/1916269 b/results/classifier/semantic-bugs/instruction/1916269 deleted file mode 100644 index 45a2ef61..00000000 --- a/results/classifier/semantic-bugs/instruction/1916269 +++ /dev/null @@ -1,70 +0,0 @@ -instruction: 0.884 -socket: 0.821 -graphic: 0.779 -device: 0.775 -other: 0.721 -network: 0.656 -semantic: 0.654 -vnc: 0.626 -mistranslation: 0.626 -boot: 0.615 -assembly: 0.473 -KVM: 0.297 - -TCG: QEMU incorrectly raises exception on SSE4.2 CRC32 instruction - -If I run FreeBSD on QEMU 5.2 with TCG acceleration -cpu Nehalem, I get a FPU exception when executing crc32 (https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=253617). This is not a problem with the default CPU (or KVM) since that does not support SSE 4.2. - -Attaching GDB shows this is triggered in target/i386/tcg/translate.c:3067 - - /* simple MMX/SSE operation */ - if (s->flags & HF_TS_MASK) { - gen_exception(s, EXCP07_PREX, pc_start - s->cs_base); - return; - } - -However, according to https://software.intel.com/sites/default/files/m/8/b/8/D9156103.pdf, page 61 the CRC32 instruction works no matter what the value of the TS bit. - -The code sequence in question is: -0xffffffff8105a4de <+126>: f2 48 0f 38 f1 de crc32q %rsi,%rbx -0xffffffff8105a4e4 <+132>: f2 48 0f 38 f1 ca crc32q %rdx,%rcx. - -This should work even with the FPU disabled. - -Could someone familiar with the target/i386 decode logic could have a look at this? It should be a rather simple change to avoid the exception for the crc32 encoding. However, I am not familiar with x86 instruction encodings so it would take me a long time to come up with a correct patch. -Thanks! - -The QEMU project is currently moving its bug tracking to another system. -For this we need to know which bugs are still valid and which could be -closed already. Thus we are setting the bug state to "Incomplete" now. - -If the bug has already been fixed in the latest upstream version of QEMU, -then please close this ticket as "Fix released". - -If it is not fixed yet and you think that this bug report here is still -valid, then you have two options: - -1) If you already have an account on gitlab.com, please open a new ticket -for this problem in our new tracker here: - - https://gitlab.com/qemu-project/qemu/-/issues - -and then close this ticket here on Launchpad (or let it expire auto- -matically after 60 days). Please mention the URL of this bug ticket on -Launchpad in the new ticket on GitLab. - -2) If you don't have an account on gitlab.com and don't intend to get -one, but still would like to keep this ticket opened, then please switch -the state back to "New" or "Confirmed" within the next 60 days (other- -wise it will get closed as "Expired"). We will then eventually migrate -the ticket automatically to the new system (but you won't be the reporter -of the bug in the new system and thus you won't get notified on changes -anymore). - -Thank you and sorry for the inconvenience. - - -[Expired for QEMU because there has been no activity for 60 days.] - -Reported on GitLab as https://gitlab.com/qemu-project/qemu/-/issues/427 - |