similar to: Function arguments pass by value or by reference.

Hello, I'm new to LLVM and I recently hit a weird problem about inlining behavior. I managed to get a minimal repro and the symptom of the issue, but I couldn't understand the root cause or how I should properly handle this issue. Below is an IR code consisting of two functions '_Z2fnP10TestStructi' and 'testfn', with the latter calling the former. One would expect the

Hi David, Thanks for your quick response! I now understand the reason that inlining cannot be done on functions with different target-attributes. Thanks for your explanation! However, I think I didn't fully understand your solution; it would be nice if you would like to elaborate a bit more. Here's a bit more info on my current workflow: (1) The clang++ compiler builds C++ source file

Thank you so much David! After thinking a bit more I agree with you that attempting to add 'target-features' to my functions seem to be the safest approach of all. I noticed that if I mark the clang++ function as 'AlwaysInline', the inlining is performed normally. Is this a potential bug, given what you said that LLVM may accidentally move code using advanced cpu features outside

Hello Anton > %1 = tail call i32 (i8*, ...)* @printf(i8* noalias getelementptr ([16 x > > i8]* @.str, i32 0, i32 0), i32 %0) nounwind > > %10 = call i32 (i8*, ...)* @printf(i8* noalias getelementptr ([11 x i8]* > > @.str2, i32 0, i32 0), i32 5) nounwind > > > > Instruction::isSameOperationAs() returns false for those two. Is it a > > bug or I misunderstood

I'm now writing a pass and I wanna ask a question about how to duplicate the function and add duplicated arguments in llvm, for example: func(int a, char *b) -> func(int a, char *b, int a1, char *b1) I'm now stuck at using "getOrInsertFunction" and how to handle "getArgumentList", please share your opinion, thanks a lot! James

Artur, > OK, I just need the same signature for both of those instructions. Both are callinsts of same function, isn't that enough? Since it's a variadic function there is also a bitcast to proper type. So, looking for type of callee (not result, but function type!) you'll obtain the real "signature" of callee and if you'll strip all pointer cast you'll obtain the

Just curious... Does anyone know if any companies using Asterisk on embedded hardware (out at the customer premisis), such as the Soekris Net4801, to provide VOIP service? Doug.

Hi, I am doing a project involving checking a called specific function’s argument. Suppose that the function is int f(const char* str). When I am analyzing such a snippet: f("hello") , then compiled by Clang, I will have the “hello” as a *Constant Array* in the IR code. My goal is to call APIs of LLVM to get the “hello” from IR code. Now suppose the I got the llvm::Function* fn from

Hi everyone, Nick and Philip suggested something yesterday that I'd also thought about: supporting attributes on values (http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20140908/234323.html). The primary motivation for this is to provide a way of attaching pointer information, such as noalias, nonnull and dereferenceable(n), to pointers generated by loads. Doing this for pointers

Hi all, At the dev meeting I promised to update everyone on where my work with opaque pointers is right now. It's taken me a while, but at least it's the same year! Current Status ============== I've put two branches up at https://github.com/TNorthover/llvm-project: "opaque-ptr" which has most of the real work so far; and "opaque-ptr-always" that additionally has

Hi, In the past months, several options have been presented for making byval (and similar attributes, such as inalloca or sret) work with opaque pointers. The main two I've seen were byval(T) and byval(N) where N is the size of T. They both have their upsides and downsides, for example: byval(T) would be a type-parametric attribute, which, AFAIK, does not already exist and may complicate

> Do all tests need it? Align is just for non-default alignment (> align(1)) so it may be OK for the tests to omit it & it's probably not right to /require/ an align attribute on a byval parameter. I've had to fix some of the tests which checked that the right alignment was applied, by looking at the generated asm, but had no "align A" attributes and relied on the

I have three modules: ----------------------------------------------------------------- s1.ll: %0 = type <{ i32, i32 }> define void @s1(%0* byval %myStruct) nounwind { return: ret void } ----------------------------------------------------------------- s2.ll: %0 = type <{ i32, i32 }> define void @s2(%0* byval %myStruct) nounwind { return: ret void }

On May 9, 2011, at 1:41 PM, Renato Golin wrote: [snip] > One example is the struct byval. The ARM back-end still doesn't > support struct byval (maybe now it does, I was away for a while), The ARM backend now supports struct byval for APCS. Extending it to support AAPCS shouldn't be too difficult. Alas, I won't have time to revisit this in the near future. stuart

Hi Tim, Thought about it last night and was coming to the same conclusion. 1. it cant be done at the end during lowering (target backend). 2. it should be part of llvm as the byVal needs to be handled. As a twist, I have been told that llvm-gcc can lower byVal into memcpy in the callee. I may take a look at this. I wonder if it ever emits 'byVal'... I still feel I don't understand

On Wed, May 11, 2011 at 11:42 PM, Stuart Hastings <stuart at apple.com> wrote: > > On May 9, 2011, at 1:41 PM, Renato Golin wrote: > > [snip] > >> One example is the struct byval. The ARM back-end still doesn't >> support struct byval (maybe now it does, I was away for a while), > > The ARM backend now supports struct byval for APCS.  Extending it to

LLVM developers, I was wondering if the program would still be safe if I strip the byval attributes from the parameters in the entire bitcode. LLVM language reference manual states that "The attribute implies that a hidden copy of the pointee is made between the caller and the callee, so the callee is unable to modify the value in the callee. This attribute is only valid on LLVM pointer

It is problematic when byval argument is not from address space 0. When the default alloca address space is 0, should we consider this IR illegal? define internal i32 @bar(i32 addrspace(1)* byval %a) alwaysinline From: Reid Kleckner [mailto:rnk at google.com] Sent: Tuesday, September 25, 2018 2:38 PM To: Pan, Wei <wei.pan at intel.com> Cc: llvm-dev <llvm-dev at lists.llvm.org>

Hi Xiaoyi, this looks like a bug to me - please file a bug report. Ciao, Duncan. On 01/11/12 04:35, Guo, Xiaoyi wrote: > I have three modules: > ----------------------------------------------------------------- > s1.ll: > > %0 = type <{ i32, i32 }> > > define void @s1(%0* byval %myStruct) nounwind { > return: > ret void > } >

This sounds right to me. If there is no objection, I will implement a patch to enforce this in langref and IR verifier. -----Original Message----- From: Friedman, Eli [mailto:efriedma at codeaurora.org] Sent: Tuesday, September 25, 2018 3:07 PM To: Pan, Wei <wei.pan at intel.com>; Reid Kleckner <rnk at google.com> Cc: llvm-dev <llvm-dev at lists.llvm.org> Subject: Re: