similar to: MachineFunction Instructions Pass using Segment Registers

More specifically there is no instruction that can add/subtract segment registers. They can only be updated my the mov segment register instructions, opcodes 0x8c and 0x8e in x86 assembly. I suggest you write the text version of the assembly you want to generate and assemble it with llvm-mc. This will tell you if its even valid. After that you can use -show-inst to print the names of the

The size suffix thing is a weird quirk in our assembler I should look into fixing. Instructions in at&t syntax usually have a size suffix that is often optional For example: add %ax, %bx and addw %ax, %bx Are equivalent because the register name indicates the size. but for an instruction like this addw $1, (%ax) There is nothing to infer the size from so an explicit suffix is

This shouldn't have parsed. movq (%gs), %r14 That's trying to use%gs as a base register which isn't valid. GNU assembler rejects it. And coincidentally llvm-mc started rejecting it on trunk late last week. That's probably why it printed as %ebp. I don't know if there is an instruction to read the base of %gs directly. Maybe rdgsbase, but that's only available on Ivy

Dear Mr. Northover, Thank you for the quick reply. You are correct about the address-mode operands :) . I guess an important detail left out was that the basic block (call it A) that wants to calculate the address of the target stationary trampoline basic block (call it B) will be moved around in memory during run-time. Our earlier solution, before the feature was implemented to move around (A)

Dear All, I am working on a x86 backend machineFunction pass, where I am trying to save the hard coded address of an arbitrary machine basic block to memory in ASM. I know the assembly needed for this but am lost at how to construct the BuildMI(). Note that these machine basic blocks are not entry's to a function. but in the middle of the function. so using addGlobalAddress or

Comments: CheckDAGForTailCallsAndFixThem - 1. for (SelectionDAG::allnodes_iterator BE = DAG.allnodes_begin(), + BI = prior(DAG.allnodes_end()); BI != BE; BI--) { Please use pre-decrement instead of post-decrement. 2. The function is slower than it should be. You are scanning all the nodes in the DAG twice. You should just examine DAG.getRoot() to make determine whether it's a

-----Original Message----- From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of John Criswell Sent: Tuesday, September 11, 2012 1:42 PM To: Steve Checkoway Cc: LLVMdev at cs.uiuc.edu Subject: Re: [LLVMdev] Need Help Understanding Operands in X86 MachineFunctionPass ... > >> The code for adding the 32-bit instruction is: >> >>

On Sep 11, 2012, at 10:57 AM, John Criswell wrote: > I'm working on an X86 MachineFunctionPass that adds prefetch instructions to a function. I have code that adds a "prefetchnta <constant address>" instruction to x86 32-bit code. What I want to do is to add a "prefetchnta <constant address>" instruction to x86_64 code. Given that you don't actually

Hi Evan, I incoporated the changes you request but to the following i have got a question: > Also, moving the option > there will allow us to change fastcc ABI (callee popping arguments) > only when this option is on. See Chris' email: I am not to sure on that. because that would make modules compiled with the flag on incompatible with ones compiled without the flag off as

On 9/11/12 12:10 PM, Stephen Checkoway wrote: > On Sep 11, 2012, at 10:57 AM, John Criswell wrote: > >> I'm working on an X86 MachineFunctionPass that adds prefetch instructions to a function. I have code that adds a "prefetchnta <constant address>" instruction to x86 32-bit code. What I want to do is to add a "prefetchnta <constant address>"

Hi, I'm trying to implement __builtin_setjmp / __builtin_longjmp for Sparc processors. I think I'm very close, but I can't work out how to issue BuildMI-type instructions to load the address of the recovery location (set in setjmp) into a register using the SETHI / OR combination. I can't see any equivalent code anywhere else in Sparc. I imagine this is similar if I try to make a

There are 11 BuildMI() functions in MachineInstrBuilder.h including four using the iterator and one using an instruction. But I just don't think that's it. The creation of the new instruction works fine (works fine with OldMI as well) and the new instruction is present in the assembly output. The problem is removing the old instruction correctly. > The loop header needs to be

On 02/15/2013 03:07 PM, Jakob Stoklund Olesen wrote: > On Feb 15, 2013, at 1:21 PM, Reed Kotler <rkotler at mips.com> wrote: > >> I want to have some functions that create machine instructions, not specifying which machine function or basic block or iterator they are part of. > All machine instructions must be created by a machine function. It provides the context for memory

I ended up settling on a scheme which I'm not completely happy with but it's the best I can see to do. const MCInstrDesc& AddiuSpImm(int64_t Imm) const; and then if (isInt<16>(-Remainder)) BuildMI(MBB, I, DL, AddiuSpImm(-Remainder)).addImm(-Remainder); So the AddiuSpImm choses which instruction description to use depending on the immediate value and then

This seems a very natural approach but I probably am having a trouble with the iterator invalidation. However, looking at other peephole optimizers passes, I couldn't see how to do this: #define BUILD_INS(opcode, new_reg, i) \ BuildMI(*MBB, MBBI, MBBI->getDebugLoc(), TII->get(X86::opcode)) \ .addReg(X86::new_reg, kill).addImm(i) for

Hi, I'm having trouble using virtual register in the X86 backend. I implemented a new intrinsic and I use a custom inserter. The goal of the intrinsic is to set the content of the stack to zero at the end of each function. Here is my code: MachineBasicBlock * X86TargetLowering::EmitBURNSTACKWithCustomInserter( MachineInstr *MI, MachineBasicBlock

Is there are reason why ConstantInt::getRawValue method can't be moved one step into class hierarchy, into ConstantIntegral::getRawValue The reason I'd like this is that to handle both ConstantInt and ConstantBool, I need the following: if (ConstantInt* CI = dyn_cast<ConstantInt>(V)) { BuildMI(*MBB, IPt, NM::MOVE, 1, Reg).addImm(CI->getRawValue()); } if

On Oct 5, 2007, at 2:42 AM, Arnold Schwaighofer wrote: > Hi Evan, > I incoporated the changes you request but to the following i have got > a question: > >> Also, moving the option >> there will allow us to change fastcc ABI (callee popping arguments) >> only when this option is on. See Chris' email: > > I am not to sure on that. because that would make

Sorry, this is the part in ARMLoadStoreOptimizer.cpp that creates a LDRD instruction. Ops.pop_back(); Ops.pop_back(); // Form the pair instruction. if (isLd) { MachineInstrBuilder MIB = BuildMI(*MBB, InsertPos, dl, TII->get(NewOpc)) .addReg(EvenReg, RegState::Define)

Hi, I'm still having problems implementing my custom inserter in the X86 backend. I found a solution to my last problem (http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-October/078296.html), by using a virtual register. The binary works when it's compiled in -O0, but not in -O1,-O2,... I really can't figure what I'm doing wrong... Any idea? Here is the code of my custom