Displaying 8 results from an estimated 8 matches for "__builtin_nontemporal_store".
2018 Jan 20
2
Non-Temporal hints from Loop Vectorizer
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:...
2018 Jan 20
0
Non-Temporal hints from Loop Vectorizer
...n 16, !tbaa
> !1, !nontemporal !1
>
> so that i can offload load, add, store to accelerator hardware. is it
> possible here? do i need a separate pass to detect whether the loop
> has non temporal data or polly will help here? what do you say?
From C/C++ you just need to use the
__builtin_nontemporal_store/__builtin_nontemporal_load builtins to tag
the stores/loads with the nontemporal flag.
for(i=0;i<2048;i++) {
__builtin_nontemporal_store( __builtin_nontemporal_load(b+i) +
__builtin_nontemporal_load(c + i), a + i );
}
There may be an attribute you can tag pointers with instead but I don...
2018 Jan 21
0
Non-Temporal hints from Loop Vectorizer
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, however. In the loop below...
2018 Jan 20
2
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,
2016 Jan 14
2
RFC: non-temporal fencing in LLVM IR
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"
> <...
2017 Sep 28
1
VMOVNTDQ in LLVM
This thread from last year has some additional detail regarding the hazards of aggressive MOVNT generation if you’re interested:
http://lists.llvm.org/pipermail/llvm-dev/2016-May/098980.html <http://lists.llvm.org/pipermail/llvm-dev/2016-May/098980.html>
– Steve
> On Sep 28, 2017, at 9:31 AM, Stephen Canon via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>
> What code did
2016 May 03
2
[RFC] Non-Temporal hints from Loop Vectorizer
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
2016 Jan 13
4
RFC: non-temporal fencing in LLVM IR
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