Page MenuHomePhabricator

draganm (Dragan Mladjenovic)
User

Projects

User does not belong to any projects.

User Details

User Since
Jun 14 2018, 11:38 PM (74 w, 3 d)

Recent Activity

Oct 7 2019

draganm added a comment to D68542: [Mips] Always save RA when disabling frame pointer elimination.

I don't think you can have frame-pointer based stack unwinding under current Mips ABIs, albeit this might be useful for some stack scan based unwind. Not sure tho.

You can most of the time, you just have to scan backwards to find the function prologue. Yes, it can break, but unless you have full DWARF info you can't do much better. Both FreeBSD (sys/mips/mips/db_trace.c) and Linux (arch/mips/kernel/process.c) do instruction-based unwinding on MIPS to get a good-enough backtrace on panic, so without this they can end up terminating the backtrace early. In particular, if you want a specific instance of the issue that motivated this patch, on FreeBSD, they have a panic which calls vpanic (much like printf vs vprintf), but due to being marked noreturn, $ra is dead and thus being clobbered by the call doesn't force a save like normal, so *every* panic ends up with a useless backtrace terminating at panic.

Oct 7 2019, 8:54 AM · Restricted Project
draganm added a comment to D68542: [Mips] Always save RA when disabling frame pointer elimination.

I don't think you can have frame-pointer based stack unwinding under current Mips ABIs, albeit this might be useful for some stack scan based unwind. Not sure tho.

Oct 7 2019, 7:44 AM · Restricted Project

Sep 20 2018

draganm added a comment to D52045: [Mips][FastISel] Fix selectBranch on icmp i1.

Sorry, I still have to delete some redundant empty lines. I believe that @petarj will commit it later.

Sep 20 2018, 6:37 AM
draganm added a comment to D52045: [Mips][FastISel] Fix selectBranch on icmp i1.

No, I do not have it.

Sep 20 2018, 4:59 AM

Sep 13 2018

draganm created D52045: [Mips][FastISel] Fix selectBranch on icmp i1.
Sep 13 2018, 9:49 AM

Jul 17 2018

draganm updated the diff for D49290: [Mips][FastISel] Fix handling of icmp with i1 type..

Replaced the usage of icmp i1 with xor i1 within test/CodeGen/Mips/Fast-ISel/sel1.ll . Now the test won't trigger fast-isel-abort.

Jul 17 2018, 7:21 AM

Jul 13 2018

draganm created D49290: [Mips][FastISel] Fix handling of icmp with i1 type..
Jul 13 2018, 5:45 AM
draganm abandoned D48629: Do not sext i1 constants when selecting binary ops.

Closing in favor of fixing this in Mips back-end.

Jul 13 2018, 2:33 AM

Jul 6 2018

draganm added a comment to D48629: Do not sext i1 constants when selecting binary ops.

PING.

Jul 6 2018, 5:26 AM

Jul 2 2018

draganm retitled D48642: [Mips][FastISel] Do not duplicate condition while lowering branches from [Mips][FastISel] Do not duplicate compare condition when lowering conditional branches to [Mips][FastISel] Do not duplicate condition while lowering branches.
Jul 2 2018, 1:50 AM

Jun 28 2018

draganm updated subscribers of D48642: [Mips][FastISel] Do not duplicate condition while lowering branches.
Jun 28 2018, 8:20 AM

Jun 27 2018

draganm created D48642: [Mips][FastISel] Do not duplicate condition while lowering branches.
Jun 27 2018, 6:08 AM
draganm created D48629: Do not sext i1 constants when selecting binary ops.
Jun 27 2018, 4:27 AM