similar to: [LLVMdev] implementing PIC for linux x86-64

On Fri, 2008-06-06 at 17:08 +0100, Rafael Espindola wrote: > 2008/6/6 Anton Korobeynikov <asl at math.spbu.ru>: > > Hello, Rafael > > > > Awesome! But... -ENOPATCH :( > > Attached now. Hi Rafael, Thanks a lot for working on this! I have one question about the patch; why did you choose too add a new enum, PICCallStyle, instead of reusing (possibly with some

On Jun 6, 2008, at 11:55 AM, Dan Gohman wrote: > On Fri, 2008-06-06 at 17:08 +0100, Rafael Espindola wrote: >> 2008/6/6 Anton Korobeynikov <asl at math.spbu.ru>: >>> Hello, Rafael >>> >>> Awesome! But... -ENOPATCH :( >> >> Attached now. > > Hi Rafael, > > Thanks a lot for working on this! > > I have one question about the

2008/6/6 Anton Korobeynikov <asl at math.spbu.ru>: > Hello, Rafael > > Awesome! But... -ENOPATCH :( Attached now. Thanks, -- Rafael Avila de Espindola Google Ireland Ltd. Gordon House Barrow Street Dublin 4 Ireland Registered in Dublin, Ireland Registration Number: 368047 -------------- next part -------------- A non-text attachment was scrubbed... Name: x86-64-plt.patch Type:

Hello, Rafael > With this patch I was able to bootstrap gcc in linux x86-64 with > shared libraries enabled :-) Awesome! But... -ENOPATCH :( -- With best regards, Anton Korobeynikov. Faculty of Mathematics & Mechanics, Saint Petersburg State University.

Hello, I am currently facing an issue at linking stage when compiling basic C code for an embedded PPC32 platform and linking with LLD. For external symbol linkage LLVM appears to use PLT which results in generating a R_PPC_PLTREL24 relocation, that is not support by LDD. Therefore even such a basic example cannot be built: /* s.c */ int f() { return 0; } /* t.c */ int f(); int _start() {

Hello, Rafael > On linux X86_64, calls to local but externally visible functions > should use the PLT. Access to local (same compilation unit), variables > can just use RIP relative access. Right, this is just optimization. AFAIR, current code already does this for 'normal' PIC - it just checks for linkage and doesn't assemble call via PLT for stuff with internal linkage.

Hal, I very well understand that LDD may not be in a good state for PPC32, and it would definitely need some improvements sooner or later. In fact I even submitted a patch adding a relocation to ldd just a few hours ago. However, this particular case is not related to LDD, it is a design issue and furthermore a regression in LLVM itself. I checked gcc, and neither does it try to use PLT and

> Yes, please remove PICCallStyle and have printPLT check for pic > relocation model and Subtarget.isTargetELF(). Done. > And where you are modifying this part of the code. Please rename > printGOT, printStub, and printPLT to something that indicates they are > predicate functions. Perhaps shouldPrintGOT, etc.? Done. Updated patch attached. > Thanks, > > Evan Cheers,

The attached patch adds support for PIC on linux x86-64. It also adds some tests. The patch fixes tests 1, 10 and 11. I would like to keep all tests, since I find the assembler printer code a bit hard to read, and I like to have tests around to find out if a change does what I think it does. With this patch I was able to bootstrap gcc in linux x86-64 with shared libraries enabled :-) Cheers, --

> Message: 4 > Date: Thu, 27 Oct 2016 22:04:28 +0200 > From: Joerg Sonnenberger via llvm-dev <llvm-dev at lists.llvm.org> > To: llvm-dev at lists.llvm.org > Subject: Re: [llvm-dev] PIC and mcmodel=large on x86 doesn't use any > relocations > Message-ID: <20161027200428.GA2177 at britannica.bec.de> > Content-Type: text/plain; charset=us-ascii > > On

Hi Rafael, Yes, merging gv prevents linker to do garbage collection. Should it be implemented as a peephole pass? If we do it too early, the distance between GVs are not fixed yet. PS: Below is the GCC output with "extern" hidden: ldr r2, .L2 stmfd sp!, {r3, lr} .save {r3, lr} .LPIC0: add r0, pc, r2 bl _Z4initPv(PLT) ldr r1, .L2+4 .LPIC1: add r0, pc, r1 bl _Z4initPv(PLT) ldr

> > Message: 2 > Date: Sat, 29 Oct 2016 22:36:41 +0200 > From: Joerg Sonnenberger via llvm-dev <llvm-dev at lists.llvm.org> > To: llvm-dev at lists.llvm.org > Subject: Re: [llvm-dev] PIC and mcmodel=large on x86 doesn't use any > relocations > Message-ID: <20161029203641.GB20270 at britannica.bec.de> > Content-Type: text/plain; charset=us-ascii >

>> Any thoughs? > > I'm now struggling to see how GCC justifies it. What if a different > translation-unit declared those variables in a different order? I also > can't get the same behaviour here, do you have a more complete > command-line? Ah, I see; the translation-unit that does the optimisation needs to have them as a definition (i.e. "= {0}") rather

H all, I'm looking at generating PIC code for RISC-V in the context of Linux. Not sure if anyone is working on this already, any inputs are very welcome. I'm now looking at function calls which in the RISCV backend are represented via two pseudoinstructions RISCV::TAIL and RISCV::CALL. Currently those pseudos are lowered in MCCodeEmitter. They are expanded into AUIPC and JALR

Hey Evan, At the point of the instructions you suggested I step through, X86ISelLowering has this state: - this 0x00000000005fe728 {VarArgsFrameIndex=-842150451 RegSaveFrameIndex=-842150451 VarArgsGPOffset=3452816845 ...} llvm::X86TargetLowering * const + llvm::TargetLowering {TM={...} TD=0x00000000008edac0

On Feb 12, 2008, at 5:26 PM, Chuck Rose III wrote: > Hola LLVMers, > > I’m debugging through some strangeness that I’m seeing on X64 on > windows with LLVM2.2. I had to change the code so that it would > engage the x64 target machine on windows builds, but I’ve otherwise > left LLVM 2.2 alone. The basic idea is that I’ve got a function bar > which is compiled by

We're at the point in our port of OpenVMS to x86 using LLVM to make choices on mcmodel. Given OpenVMS's history, our linker will allocate static data (ie, .data, .bss, .plt, GOT, etc.) in the bottom 32-bits of address space (ie, 00000000.xxxxxxxx). However, we support code anywhere in the 64-bit address space as PIC code (we do this on Itanium today using our own code-generator and

I know I am just back from vacations, but I am sorry to inform I will be out for some time. I am changing jobs here at Google and for some time I will have to do a bit of both. This would make it hard for me to keep track of a very vivid project like LLVM. The good news Is that this should last no more the 4 months from now and that I am moving to a software developer position that should be a

Hi Lang, Yeah, I remember this case. Basically what’s happening is that there are relocations for ELF on x86 that use a value that is present in the object image as part of the calculation for the final value that goes in the same location. If you ever find yourself applying relocations for a second time (for instance, because the loaded object location is remapped for out-of-proc execution)

Rafael, I believe MachO can't represent this relocation, even in non-PIC mode. On my Mac, I tried compiling "call 256". I got: in section __TEXT,__text reloc 0: R_ABS reloc but no absolute symbol at target address I believe the correct thing to do is: isTargetELF() && TM.getRelocationModel() == Reloc::Static This will do the right thing on ELF, and the right thing on