similar to: [LLVMdev] structure packing and misaligned members

Hi edA-qa mort-ora-y, On 12/05/13 17:13, edA-qa mort-ora-y wrote: > I'm trying to determine how to do my packed structure compilation and am > a bit unclear about how packed structures are handled. Consider this > structure: > > %struct.packed = type <{ i8, i32 }> > > Now if I get a pointer to the i32 element the pointer will not be > properly aligned for a

On 12/05/13 17:50, Duncan Sands wrote: > in LLVM, pointer types don't have an alignment associated with them. > Instead it is pointer operations that have an alignment (when relevant), > for example load and store instructions have an optional alignment. So > you need to put the alignment information onto the loads and stores that > you generate in your front-end. Okay, so I

I'm creating a struct of `{i8,i64}` and `DataLayout::getTypeAllocSize` is returning `12`. `getStructLayout` also gives an `4` offset for the second element. The native ABI, and clang, for the same type are producing a size of 16, with an alignment of 8, for the second element. This is for the system triple "x86_64-linux-gnu" What could be causing this difference in alignment and

I'm having an issue where a certain set of types and insert/extractvalue are producing the incorrect values. It appears as though extractvalue getting my sub-structure is not getting the correct data. I have these types: %outer = type { i32, %inner, i1 } %inner = type { double, i32 } The trouble is that when I have a value of type %outer then proceed to extract the components of the

That makes it more mysterious then since I am indeed only calling a main function. Perhaps I have to invoke it a different way. Here's my call I have now: auto main = linker->getModule()->getFunction( "main" ); std::vector<llvm::GenericValue> args(2); args[0].IntVal = llvm::APInt( platform::abi_int_size, 0 ); args[1].PointerVal = nullptr; llvm::GenericValue gv =

Is there a way to get the size of a type in the IR assembly code? I know the size must be known since alloca and getelementptr both implicitly use it, but I don't see any way to get access to the size directly. I know my final compiler will have to get the size itself, but I'm just doing some simple tests directly in assembly now and am hoping there is an easy way to get the size of a

Yes, but why is it even copying the memory?  It already has a pointer which it can cast and load from -- and does so in other scenarios. I'm wondering whether this copying is somehow required and I'm missing something, or it's just an artifact of the clang emitter. That is, could it not omit the memcpy and cast the original variable? On 18/04/18 19:43, Krzysztof Parzyszek via

It was the return type which was i64. I changed it also to my abi_int_size and it works now. I have to take care of a few other type translations, but it looks like MCJIT is working now. Thank you. On 08/11/13 18:12, Yaron Keren wrote: > Something must be wrong with the Function Type. Try to debug into > runFunction to see which if condition fails. > Just a guess, if this is on 64

I also saw this issue before. Llvm seems have trouble returning general struct values from functions. One easy workaround is to use packed struct type. Hope this helps. -Peng On Sunday, December 30, 2012, edA-qa mort-ora-y wrote: > I'm having an issue where a certain set of types and insert/extractvalue > are producing the incorrect values. It appears as though extractvalue >

I think I see a potential issue. My ExecutionEngine setup may not be using the same target as my object code emitting, and in this test case I'm running in the ExecutionEngine.  I'll go over this code to ensure I'm creating the same triple and see if that helps -- I'm assuming it will, since I can't imagine the exact same triple with clang would produce a different layout. On

Something must be wrong with the Function Type. Try to debug into runFunction to see which if condition fails. Just a guess, if this is on 64 bit system the first argument type may be int64 but needs to be int32. Yaron 2013/11/8 edA-qa mort-ora-y <eda-qa at disemia.com> > That makes it more mysterious then since I am indeed only calling a main > function. Perhaps I have to invoke

It sounds like your DataLayout may not match clang's for x86_64-linux. What does it say about the alignment of i64? On Wed, Apr 18, 2018 at 12:05 PM edA-qa mort-ora-y via llvm-dev < llvm-dev at lists.llvm.org> wrote: > I'm creating a struct of `{i8,i64}` and `DataLayout::getTypeAllocSize` > is returning `12`. `getStructLayout` also gives an `4` offset for the > second

Yes, I understand that as well (it's what I'm trying to recreate in my language now). I'm really wondering why it does the copy, since from what I can tell it could just as easily cast the original value and do the load without the memcpy operation. That is, the question is about the memcpy and extra alloca -- I understand what it's doing, just not why it's doing it this way.

On 19/11/13 08:03, Caldarale, Charles R wrote: >> X = { a, b, c, d, e } >> Y = { c, d, e } > In general, no. If a, b, and c were char, and d was an int, using > typical C alignments, there would be one slack byte between c and d > in X, whereas there would be three in Y. You could probably force > what you want with packed structures or by playing with the data >

I'm having a problem with my code generating empty lines and it appears to be the CLib `open` function generating an empty line when used within the JIT-VM. If I compile my program to an exe file it doesn't happen. I also have a lot of other code running in the VM without this problem, it's somehow particular to `open`. A chunk of my IR that calls `open`: defer_body_26:

I'm trying to get MCJIT working but I get the following errors: Full-featured argument passing not supported yet! UNREACHABLE executed at MCJIT.cpp:322! I'm sure the first one will be a problem, but the second one prevents me from testing anything. I don't know how to fix the problem. My code works when using the non-MC JIT, and I added to my EngineBuilder: .setUseMCJIT(true)

Is there a way to set the alignment of structure types and/or their members? I noticed that if I use the alignas keyword in c++ that clang introduces a bunch of [Y x i8] style padding. -- edA-qa mort-ora-y Leaf Creator Leaf - the language we always wanted http://leaflang.org/

Is a series of fields in a structure guaranteed to have the same layout as those fields in a structure on their own? That is, can I cast a pointer within a main structure to an equivalent type? X = { a, b, c, d, e } Y = { c, d, e } y = BitCast( StructGEP( some_x, 2 ), Y* ) Is that a valid cast? -- edA-qa mort-ora-y Leaf Creator Leaf - the language we always wanted http://leaflang.org/

I'm working on exception handling and having some trouble with type information. My personality/types work fine when running in the JIT, but when I produce object files and link them it fails. In particular, from an action record and the LSDA I get a type table entry. The problem is this doesn't appear to be pointing to a valid location. If I derefence it a segfault occurs. Are there

I'm having trouble figuring out what the error "Instruction does not dominate all uses!" means. I'm trying to construct a call to a function with two parameters. The printed IR, with error, looks like this: define i32 @add(i32, i32) { EntryBlock: %2 = add i32 %0, %1 ret i32 %2 } define i32 @eval_expr() { EntryBlock: ret i32 <badref> } Instruction does not dominate