search for: splat

Hi, During the discussion on introducing scalable vectors we established that we could use the canonical IR form for splats of scalable vector types (insert element into lane 0 of an undef vector, shuffle that with another undef vector of the same type and a zeroinitializer mask). We do run into a problem for lowering to SelectionDAG however, since the canonical form there is a BUILD_VECTOR with all elements being the...

Just spitballing... why not have a splat construct straight through LLVM? It would make the IR more readable, opposed to the insert+shuffle method. On Thu, Aug 29, 2019 at 19:06 Amara Emerson via llvm-dev < llvm-dev at lists.llvm.org> wrote: > +1 to a new node, we’d very likely do the same thing for GlobalISel and > move to...

Hi All, First of all, I am not native English speaker. While reading BUILD_VECTOR related code, for example, PPCTargetLowering::LowerBUILD_VECTOR, I see "splat" here and there. Could someone explain what it is (does splat mean the same thing across the whole code base)? Besides, from my English dictionary, I don't know why we call such thing as "splat"... :p Regards, chenwj -- Wei-Ren Chen (陳韋任) Homepage: https://people.cs.nctu.edu.t...

Hi, I noticed that ConstantFP::get automatically returns the appropriately types Constant depending on the LLVM type passed in (i.e. if called with a vector, it returns a splat vector with the given constant). Is there any simple way to do the inverse of this function? i.e., given a llvm::Value, check whether it is either a scalar of the given constant value or a splat vector with the given constant value? I can't seem to find any, and it doesn't look like the pa...

----- Original Message ----- > Hi, > > I noticed that ConstantFP::get automatically returns the > appropriately > types Constant depending on the LLVM type passed in (i.e. if called > with a vector, it returns a splat vector with the given constant). > > Is there any simple way to do the inverse of this function? i.e., > given a llvm::Value, check whether it is either a scalar of the given > constant value or a splat vector with the given constant value? I > can't seem to find any, and it doe...

Thanks, Sanjay, that makes sense. The opportunity for improving instcombining splat sounds promising. Another question about shuffle simplification. This is a testcase from test/Transforms/InstCombine/vec_shuffle.ll: define <4 x i32> @test10(<4 x i32> %tmp5) nounwind { %tmp6 = shufflevector <4 x i32> %tmp5, <4 x i32> undef, <4 x i32> <i32 1, i...

...Andrea Di Biagio <andrea.dibiagio at gmail.com > wrote: > Hi Chandler, > > Here is another test. > > When looking at the AVX codegen, I noticed that, when using the new > shuffle lowering, we no longer emit a single vbroadcastss in the case > where the shuffle performs a splat of a scalar float loaded from > memory. > > For example: > (with -mcpu=corei7-avx -x86-experimental-vector-shuffle-lowering) > vmovss (%rdi), %xmm0 > vpermilps $0, %xmm0, %xmm0 # xmm0 = xmm0[0,0,0,0] > > Instead of: > (with -mcpu=corei7-avx) > vbroadcastss (%rd...

Hi! as highlevel languages (like opencl) support operations with a vector on one side and a scalar on the other side (e.g. vector * scalar) it would be convenient if llvm ir would have a splat instruction that takes a scalar and produces a vector with all elements filled with the scalar. i assume that i'm not the first one who has this idea so what was the reason not to include such an instruction? a splat instruction would also be handy to scalarize the code as much as possible be...

Hi, We have a function in IRBuilder.h Value *CreateVectorSplat(unsigned NumElts, Value *V, const Twine &Name = "") { .. } This function creates 2 instructions - "insertelement" and "shuffle" with all-zero mask. Now I want to add Value *getSplatValue(Value *Val). This function will try to recognize the pattern - insertelement...

...#39;s called today.) > > You're talking about two very very very different things: > shuffle_vector "masks" and constant vectors. > > Yup. That's why I was absolutely mystified when you proposed the > following: > > 2. Move the functionality of "is splat" etc to method somewhere, > e.g. on SDNode. > 3. Introduce a new ShuffleVectorSDNode that only has two SDValue > operands (the two input vectors), but that also contains an array of > ints in the node (not as operands). > 4. Move the helper functions from #2 back into Shuf...

This snippet of IR is interesting: %sub.ptr.div.iS37_D = sdiv <2 x i64> %sub.ptr.sub.iS36_D, <i64 24, i64 24> %cmp10S38_D = icmp ugt <2 x i64> %sub.ptr.div.iS37_D, %splatInsMapS1_D.splat %zextS39_D = sext <2 x i1> %cmp10S38_D to <2 x i64> %BCS39_D = bitcast <2 x i64> %zextS39_D to i128 %mskS39_D = icmp ne i128 %BCS39_D, 0 br i1 %mskS39_D, label %if.then11, label %if.else It looks like %msk539_D is basically a test of whether either of...

https://bugs.freedesktop.org/show_bug.cgi?id=67277 Priority: medium Bug ID: 67277 Assignee: nouveau at lists.freedesktop.org Summary: Lockdep splat on kernel 3.10.0 QA Contact: xorg-team at lists.x.org Severity: normal Classification: Unclassified OS: Linux (All) Reporter: peter at hurleysoftware.com Hardware: x86-64 (AMD64) Status: NEW Version: unspecified...

On Tue, Sep 23, 2014 at 2:35 PM, Simon Pilgrim <llvm-dev at redking.me.uk> wrote: > If you don’t want to spend time on this, I’d be happy to create a > candidate patch for review? I’ve been unclear if you were taking patches > for your shuffle work prior to it becoming the default. While I'm happy to work on it, I'm even more happy to have patches. =D -------------- next

------------------------------------ IR ------------------------------------------------------------------ if.then.i.i.i.i.i.i: ; preds = %if.then4 %S25_D = zext <2 x i32> %splatLDS17_D.splat to <2 x i64> %umul_with_overflow.i.iS26_D = shl <2 x i64> %S25_D, <i64 3, i64 3> %extumul_with_overflow.i.iS26_D = extractelement <2 x i64> %umul_with_overflow.i.iS26_D, i32 1 %call5.i.i = tail call noalias i8* @_Znam(i64 %extumul_with_overflow.i.iS26_D) #...

...18 11:38:19, Mark Rutland wrote: > On Mon, Feb 26, 2018 at 11:52:56AM +0100, Jan Kara wrote: > > On Fri 23-02-18 15:47:36, Mark Rutland wrote: > > > Hi all, > > > > > > While fuzzing arm64/v4.16-rc2 with syzkaller, I simultaneously hit a > > > number of splats in the block layer: > > > > > > * inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-R} usage in > > > jbd2_trans_will_send_data_barrier > > > > > > * BUG: sleeping function called from invalid context at mm/mempool.c:320 > > > > > > *...

On Mon, Feb 26, 2018 at 11:52:56AM +0100, Jan Kara wrote: > On Fri 23-02-18 15:47:36, Mark Rutland wrote: > > Hi all, > > > > While fuzzing arm64/v4.16-rc2 with syzkaller, I simultaneously hit a > > number of splats in the block layer: > > > > * inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-R} usage in > > jbd2_trans_will_send_data_barrier > > > > * BUG: sleeping function called from invalid context at mm/mempool.c:320 > > > > * WARNING: CPU: 0 PID: 0 at block/bl...

On 07/24/2015 03:42 AM, Benjamin Kramer wrote: >> On 24.07.2015, at 08:06, zhi chen <zchenhn at gmail.com> wrote: >> >> It seems that that it's hard to vectorize int64 in LLVM. For example, LLVM 3.4 generates very complicated code for the following IR. I am running on a Haswell processor. Is it because there is no alternative AVX/2 instructions for int64? The same thing

On Mon, Feb 26, 2018 at 11:52:56AM +0100, Jan Kara wrote: > On Fri 23-02-18 15:47:36, Mark Rutland wrote: > > Hi all, > > > > While fuzzing arm64/v4.16-rc2 with syzkaller, I simultaneously hit a > > number of splats in the block layer: > > > > * inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-R} usage in > > jbd2_trans_will_send_data_barrier > > > > * BUG: sleeping function called from invalid context at mm/mempool.c:320 > > > > * WARNING: CPU: 0 PID: 0 at block/bl...

...dding a new node class is > threefold: > > I don't see this. Adding some helper methods would have the same > functionality. And the first thing the helper method would have to check is if this SDNode is a BUILD_VECTOR node, right? b) Where else would one encapsulate a constant splat predicate? >> SelectionDAG and SDNode are not good classes for constant splat detection, >> since it's functionality specific to building vectors. >> > > Eventually we need to add a ShuffleSDNode class for other reasons. Parking > it on SelectionDAG or SDNode is not...

...es, we cannot specify all the elements as we can for > fixed-length vectors; fortunately only a small number of easily synthesized > patterns are required for autovectorization. The `zeroinitializer` constant > can be used in the same manner as fixed-length vectors for a constant zero > splat. This can then be combined with `insertelement` and `shufflevector` > to create arbitrary value splats in the same manner as fixed-length vectors. > > For constants consisting of a sequence of values, an experimental `stepvector` > intrinsic has been added to represent a simple constan...