search for: legalised

I'm a new LLVM developer contributing patches for the AVR platform and I'm trying to understand which parts of the code base are malfunctioning in my case. This LLVM IR... define hidden i32 @setServoAngle3(i32) local_unnamed_addr { entry: %1 = call i32 @myExternalFunction1(i32 %0, i32 119) ret i32 %1 } declare i32 @myExternalFunction1(i32, i32) Is being lowered to this assembly

Hi Tim, Thank you for your reply. It actually helped a lot to narrow the issue, as previously I didn’t even know where to look. I have been following the code in the debugger, specially the LSRInstance::SolveRecurse function. This function traverses recursively all possible ‘Formulae’, and determines the best instruction combination for the loop generation, based on minimal cost. The

OK, I'm clear on scalars. Data races are thankfully OK in this context. Densely packing vectors sounds efficient and is clear in the case where lanes * width is a multiple of 8 bits. I don't think I understand how it works in other cases. If we could take store <4 x i8> truncating to <4 x i7> as an example. This can be converted into four scalar i8 -> i7 stores with

Alex, ping? There was a thread about moving Risc-V out of experimental but I think it didn't go anywhere? Separately, do the listed patches sound okay for merging? Thanks, Hans On Fri, Jan 25, 2019 at 4:40 PM Bruce Hoult <brucehoult at sifive.com> wrote: > > In https://llvm.org/svn/llvm-project/llvm/branches/release_80 I find > that RISCV is still in

...hapes and legalise them later on. I may be severely outdated in my opinion, and happy to be corrected, but I don't think it would be totally egregious to carry on with (whole numbered) vector shapes that aren't strictly legal, as long as you guarantee that *any* such pattern gets correctly legalised by the lowering. If you can make the adversarial cases performing on top of that, it's a bonus, not a target. Hope this helps. cheers, --renato

I come across a situation that I am having a hard time to understand. When I compile the following code : char *tst( char *dest, const char *src, unsigned int len ) { for (int i=0 ; i<len ; i++) { dest[i] = src[i]; } return dest; } Clang generates this for the ‘for’ body: for.body: ; preds = %for.cond %arrayidx = getelementptr inbounds i8,

Hi, I would like to restart the conversation regarding adding SVE support to LLVM. This time I am framing things from the code generation point of view because our immediate priority is llvm-mc support rather than auto-vectorisation. Can you please review the following text outlining MVT changes we would like to make so SVE instructions can be added to the AArch64 Target. My overriding

I'm trying to figure out how to map more complex CISC instructions now. For example on the 68000, you have things like -- add.w (a0)+,(a1)+ So that equates to: temp1 = load a0 add 2, a0 temp2 = load a1 temp1 = add temp1, temp2 store temp1, a1 add 2, a1 How do I express that in a form for LLVM? I see things like pre_store and post_store, but I cant find anything in the way of documentation

...e vector width). So vectorization in Polly was very > easy to implement and already works reasonable well. Ok, this comes with another current change in LLVM: OpenCL. I explain. OpenCL has very large (and odd) vector sizes, that if implemented to vectorized units (like SSE or NEON), need to be legalised. Such a pass should be target specific and polly could make use of that. If polly always generate vector code (instead of reason if the number of unrolled operations are the same as the current target being compiled into), the later legalisation pass can deal with the odd sized vectors and transfo...

Hi Richard, Thanks for working on this. We should probably move this discussion to llvm-dev because it is not strictly related to the patch review anymore. The code below is not representative of general c/c++ code. Usually only domain specific language (such as OpenCL) contain vector instructions. The LLVM pass manager configuration (pass manager builder) is designed for C/C++ compilers, not

Hi David, > On Nov 18, 2015, at 11:55 AM, David Chisnall <David.Chisnall at cl.cam.ac.uk> wrote: > > Hi Quentin, > > On 18 Nov 2015, at 19:26, Quentin Colombet via llvm-dev <llvm-dev at lists.llvm.org> wrote: >> >> In the section “Goals", I defined (repeated for people that saw the talk) the goals for the Global ISel design. >> - Do you see

Nadav and other vectorizer folks- Is there any plan to support special idioms in the loop vectorizer like sum of absolute difference (SAD) ? We see some useful cases where llvm is losing performance at -O3 due to SADs not being vectorized (hence PSADBWs not being generated). Also, since the abs() call is already lowered to a sequence of 'icmp; neg; select' by simplifylibcalls (in -O3),

This question came about through reviewing work from Leslie Zhai on GlobalISel support for RISC-V, which also motivated me to revisit code which I've always felt was a bit clunky. Calling convention lowering in LLVM is typically handled by functions conforming to the CCAssignFn typedef: typedef bool CCAssignFn(unsigned ValNo, MVT ValVT, MVT LocVT,

----- Original Message ----- > From: "Renato Golin" <renato.golin at linaro.org> > To: "Dibyendu Das" <Dibyendu.Das at amd.com> > Cc: llvmdev at cs.uiuc.edu > Sent: Tuesday, November 4, 2014 5:23:30 AM > Subject: Re: [LLVMdev] supporting SAD in loop vectorizer > > On 4 November 2014 11:06, Das, Dibyendu <Dibyendu.Das at amd.com> wrote:

I think this is broken in at least one place when legalising the DAG. This llvm ir: %3 = call { i16, i1 } @llvm.umul.with.overflow.i16(i16 %2, i16 11) Fails to lower correctly on AVR but the problem is, unfortunately, not just coming from the AVR Target code and I am not sure it can be cleanly fixed just there. (But I would be very happy to be proved wrong as I'm very new to this.) The above

Hi Dan, If you set the node's action to "Custom", you should be able to interfere in the type legalisation phase (before it gets promoted to a 64-bit MUL) by overriding the "ReplaceNodeResults" function. You could either expand it to a different libcall directly there, or replace it with a target-specific node (say XXXISD::MUL32) which claims to take i64 types but you

This is a question about optimizing the code generation in a (new) Z80 backend: The CPU has a couple of 8 bit physical registers, e.g. H, L, D and E, which are overlaid in 16 bit register pairs named HL and DE. It has also a native instruction to load a 16 bit immediate value into a 16 bit register pair (HL or DE), e.g.: LD HL,<imm16> Now when having a sequence of loading two 16

> On 25 May 2018, at 01:46, Aaron via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hi all, > > LLVM optimization pass gives an error "Terminator found in the middle of a basic block!" since basic block IR may have multiple "ret" instructions. It seems LLVM does not accept multiple return in a basic block by default. > Yes, if you’re inserting

> On 2 May 2017, at 8:48 am, Tom Stellard <tstellar at redhat.com> wrote: > You would probably need to write a new tablegen backend to generate > instruction tables that would be used outside of LLVM. I think I need to write one anyway because I need to generate lots of tables other than the instruction table (there are no registers and therefore no register table), at least one

On 5/3/2017 12:04 PM, Tom Stellard via llvm-dev wrote: > On 05/03/2017 11:19 AM, Nicholas Wilson wrote: >>> Right, what I was trying to say is that there are more benefits from >>> having this not be a target than there is from having it be a target. >> Please enumerate them, I have seen none posted so far . The implied “it is what all the the other backends do” w.r.t