search for: jelesnianski

...f there is an instruction to read the base of %gs directly. Maybe rdgsbase, but that's only available on Ivy Bridge and later CPUs.. But ussing %gs as part of the memory address for any other instruction is automatically relative to the base of %gs. ~Craig On Tue, Jun 26, 2018 at 12:57 PM K Jelesnianski <kjski at vt.edu> wrote: > Dear Craig, > > Thanks for the help so far. I have rewritten my assembly to comply > with user-land not being able to directly modify the segment registers > %GS/%FS. I used llvm-mc with -show-inst to get the equivalent LLVM > instruction + operan...

...rent instructions from each other. So for example, if two instructions only differ in the lower case letters and one says "rr" and one says "rm", the first is the register form and the second is the memory form of the same instruction. ~Craig On Sat, Jun 23, 2018 at 7:55 PM K Jelesnianski <kjski at vt.edu> wrote: > Dear Craig, > > Thank you super much for the quick reply! Yea I'm still new to working > on the back-end and that sounds great. I already have the raw assembly > of what I want to accomplish so this is perfect. I just tried it and > yea, I wil...

...gets encoded only 3 or 4 bits > of the register value make it into the binary encoding. Objdump just > extracts those 3 or 4 bits back out and prints one of the > EAX/EBX/EDX/ECX/EBP registers that those bits correspond to. > > ~Craig > > > On Sat, Jun 23, 2018 at 5:28 PM K Jelesnianski via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> Dear All, >> >> Currently I am trying to inject custom x86-64 assembly into a >> functions entry basic block. More specifically, I am trying to build >> assembly in a machine function pass from scratc...

...airly complicated hybrid approach between an IR Function pass with Backend support. I would like to stay as a single machinefunction pass. Believe me I would do this at the IR level if I didnt need to specifically use the segment registers. Thanks for the help in advance! Sincerely, Christopher Jelesnianski Graduate Research Assistant Virginia Tech

...Pass to add the trampolines per module (file) (so far I have only created BasicBlock, MachineBasicBlock, and MachineFunction passes)?? Do I need to make a separate custom section for these trampolines symbols, or can I just add them to the .text section? Thanks again for your reply. Sincerely, K Jelesnianski -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20180922/bc574791/attachment.html>

...te out my metadata into a output text file (gathered from the IR pass) and have the MF pass read that output text file in again to do the tagging I need. (Another issue here is how to code opt to take in a text file as pass data and NOT a file to be compiled/opted) Thanks! Sincerely, Christopher Jelesnianski Virginia Tech Research Assistant

...) $ make -j40 (This is where error happens) I have worked with llvm for over 6 years now and still never ran into something so bizarre. Any help is appreciated. I have looked online for a few hours now and found similar postings but no clear replies or solutions for this. Sincerely, Christopher Jelesnianski

Thanks for your quick reply. I have also tried disabling build shared libs, specifying via "-DBUILD_SHARED_LIBS=OFF" in my cmake config line However I am getting the same exact error with this flag specified as well. Just an idea, would removing all llvm/clang instances/libs on my machine work? Do you know what the default location is of these shared/static llvm libraries that are

...ary symbol or 2) /usr/bin/ld: /tmp/foo-d523b6.o: relocation R_X86_64_32S against `.text' can not be used when making a shared object; recompile with -fPIC /usr/bin/ld: final link failed: Nonrepresentable section on output Any suggestions? Much appreciated for taking a look! Sincerely, K Jelesnianski -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20180922/f830f042/attachment.html>

...ntrinsics, which carry the metadata you require. The backend won't touch such elements, since it does not know how to operate on them. Clearly, it may come with several important drawbacks. Have a nice day :) -- Lorenzo > Message: 8 > Date: Thu, 5 Nov 2020 13:56:57 -0500 > From: K Jelesnianski via llvm-dev<llvm-dev at lists.llvm.org> > To: llvm-dev<llvm-dev at lists.llvm.org> > Subject: [llvm-dev] How to pass custom metadata from IR module pass to > backend MF pass? > Message-ID: > <CAH=yU0a8YX=c3Jih_52PXCvodW5dT1ogsd3MHrEQVqJ_A0raOQ at mail.gmail.com>...

...ess(), but doesn't need the Value. Maybe MDNode metadata could be of use here? TLDR: How can I leverage a Value that is of StructType generated from a C++ object to get its vtable ptr in LLVM to use as a Value for a to-be-inserted function call?? Thank you in advance! Sincerely, Christopher Jelesnianski Graduate Research Assistant, Virginia Tech

Dear llvm-dev-list, I have created my own custom section to be added at the end into a binary upon compilation which contains address of all basic blocks. As the final address of the basic block is not known until link time, I collect the MCSymbol* Symbol Values per BB in a temp array and at the in the custom section and emit it (emitSymbolValue) into my section within EmitEndOfAsmFile() I have