similar to: Non-Temporal hints from Loop Vectorizer

Actually i am working on vector accelerator which will perform those instructions which are non temporal. for instance if i have this loop for(i=0;i<2048;i++) a[i]=b[i]+c[i]; currently it emits following IR; %0 = getelementptr inbounds [2048 x i32], [2048 x i32]* @b, i64 0, i64 %index %1 = bitcast i32* %0 to <16 x i32>* %wide.load = load <16 x i32>, <16 x i32>* %1,

On 20/01/2018 17:44, hameeza ahmed via llvm-dev wrote: > Hello, > > My work deals with non-temporal loads and stores i found non-temporal > meta data in llvm documentation but its not shown in IR. > > How to get non-temporal meta data? llvm\test\CodeGen\X86\nontemporal-loads.ll shows how to create nt vector loads in IR - is that what you're after? Simon.

On 20/01/2018 18:16, hameeza ahmed wrote: > Actually i am working on vector accelerator which will perform those > instructions which are non temporal. > > for instance if i have this loop > > for(i=0;i<2048;i++) > a[i]=b[i]+c[i]; > > currently it emits following IR; > > >   %0 = getelementptr inbounds [2048 x i32], [2048 x i32]* @b, i64 0, > i64 %index

i have already seen usage of __builtin_nontemporal_store but i want to automate identification of non temporal loads/stores. i think i need to go for a pass. is it possiblee to detect non temporal loops without polly? On Sat, Jan 20, 2018 at 11:26 PM, Simon Pilgrim <llvm-dev at redking.me.uk> wrote: > On 20/01/2018 18:16, hameeza ahmed wrote: > > Actually i am working on vector

On 01/20/2018 12:29 PM, hameeza ahmed via llvm-dev wrote: > i have already seen usage of __builtin_nontemporal_store but i want to > automate identification of non temporal loads/stores. i think i need > to go for a pass. is it possiblee to detect non temporal loops without > polly? Yes, but we don't have anything that does that right now. The cost modeling is non-trivial,

Hello all, I've been wondering why Clang doesn't generate non-temporal stores when compiling the STREAM benchmark [1] and therefore doesn't yield optimal results. It turned out that the Loop Vectorizer correctly vectorizes the arithmetic operations and also merges the loads and stores into vector operations. However it doesn't add the '!nontemporal' metadata which would

Steve Canon is on vacation, so I’m going to word for word quote his take on the compiler autogenerating nontemporal hints: "nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope nope n” — Steve Canon —escha > On May 3, 2016, at 10:26 AM, via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Non-temporal hints

Hi JF, Philip, Clang currently has __builtin_nontemporal_store and __builtin_nontemporal_load. How will the usage model for those change? Thanks again, Hal ----- Original Message ----- > From: "Philip Reames via llvm-dev" <llvm-dev at lists.llvm.org> > To: "JF Bastien" <jfb at google.com>, "llvm-dev" > <llvm-dev at lists.llvm.org> >

Hello, fencing enthusiasts! *TL;DR:* We'd like to propose an addition to the LLVM memory model requiring non-temporal accesses be surrounded by non-temporal load barriers and non-temporal store barriers, and we'd like to add such orderings to the fence IR opcode. We are open to different approaches, hence this email instead of a patch. *Who's "we"?* Philip Reames brought

On Thu, Jan 14, 2016 at 1:10 PM, David Majnemer via llvm-dev < llvm-dev at lists.llvm.org> wrote: > > > On Wed, Jan 13, 2016 at 7:00 PM, Hans Boehm via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> I agree with Tim's assessment for ARM. That's interesting; I wasn't >> previously aware of that instruction. >> >> My

On Thu, Jan 14, 2016 at 1:35 PM, David Majnemer <david.majnemer at gmail.com> wrote: > > > On Thu, Jan 14, 2016 at 1:13 PM, JF Bastien <jfb at google.com> wrote: > >> On Thu, Jan 14, 2016 at 1:10 PM, David Majnemer via llvm-dev < >> llvm-dev at lists.llvm.org> wrote: >> >>> >>> >>> On Wed, Jan 13, 2016 at 7:00 PM, Hans

I agree with Tim's assessment for ARM. That's interesting; I wasn't previously aware of that instruction. My understanding is that Alpha would have the same problem for normal loads. I'm all in favor of more systematic handling of the fences associated with x86 non-temporal accesses. AFAICT, nontemporal loads and stores seem to have different fencing rules on x86, none of them

On Wed, Jan 13, 2016 at 10:32 AM, John Brawn <John.Brawn at arm.com> wrote: > *What about non-x86 architectures?* > > > > Architectures such as ARMv8 support non-temporal instructions and require > barriers such as DMB nshld to order loads and DMB nshst to order stores. > > > > Even ARM's address-dependency rule (a.k.a. the ill-fated >

On 01/14/2016 04:05 PM, Hans Boehm via llvm-dev wrote: > > > On Thu, Jan 14, 2016 at 1:37 PM, JF Bastien <jfb at google.com > <mailto:jfb at google.com>> wrote: > > On Thu, Jan 14, 2016 at 1:35 PM, David Majnemer > <david.majnemer at gmail.com <mailto:david.majnemer at gmail.com>> wrote: > > > > On Thu, Jan 14, 2016 at 1:13

Thank You. i used -polly-ast-detect-parallel but there is no coincident info generated; my c code is simple vec-sum as follows; #include <stdio.h> int a[2048], b[2048], c[2048]; foo () { int i; for (i=0; i<2048; i++) { a[i]=b[5] + c[i]; } } i executed following commands; $clang -S -emit-llvm vec-sum.cpp -march=native -O3 -mllvm -disable-llvm-optzns -o vec-sum.s $opt -S

While hacking around in the SelectionDAG build code, I've made the isVolatile, (new) isNonTemporal and Alignment parameters to SelectionDAG::getLoad/getStore and friends non-default. I've already caught one bug in the XCore backend by doing this: if (Offset % 4 == 0) { // We've managed to infer better alignment information than the load // already has. Use an aligned

Hello, i have been working with an accelerator backend. the accelerator has large vector/simd units. i want streaming loops (non-temporal) vectorized present in code to be offloaded to accelerator simd units. i find polly really suitable for this. i am thinking if the generated IR is passed to polly and then it analyzes loop to know it posses no reuse, if such loop is identified accelerator

On Thursday 11 February 2010 17:40:24 David Greene wrote: > While hacking around in the SelectionDAG build code, I've made the > isVolatile, (new) isNonTemporal and Alignment parameters to > SelectionDAG::getLoad/getStore and friends non-default. > > I've already caught one bug in the XCore backend by doing this: > > if (Offset % 4 == 0) { > // We've

On Thursday 11 February 2010 14:44:23 Dan Gohman wrote: > > Then we can't use it to hold a non-temporal flag. The operand might be > > non-temporal in one context but it may not be in another. > > Sharing only happens when two instructions have the "same" memory > reference info. You just need to make sure that the non-temporal > flag is significant.

On 07/04/2013 01:39 PM, Stéphane Letz wrote: > Hi, > > Our DSL can generate C or directly generate LLVM IR. With LLVM 3.3, we can vectorize the C produced code using clang with -O3, or clang with -O1 then opt -O3 -vectorize-loops. But the same program generating LLVM IR version cannot be vectorized with opt -O3 -vectorize-loops. So our guess is that our generated LLVM IR lacks some