similar to: linear programming in R | limits to what it can do, or my mistake?

Apart from the fact that the statement "such that t1+t2+t3+t4=2970 (as it must)" is not correct, the LP can be implemented as follows: library(lpSolve) LHS <- rbind( c(0,0,0,0, 1, 0, 0,0), c(1,0,0,0,-1, 1, 0,0), c(0,1,0,0, 0,-1, 1,0), c(0,0,1,0, 0, 0,-1,1), cbind(-diag(4),diag(4)), c(0,0,0,0,0,1,0,0), c(0,0,0,0,0,0,1,0), c(0,0,0,0,0,0,0,1) ) RHS <-

also i further run the following command; llc -debug filer-knl_o3.ll and its output is attached here. by looking at the output can we say that legalization runs fine and the error is due to instruction selection/ pattern matching which is not yet implemented? so do i need to worry and try to correct it at this stage or should i move forward to implement instruction selection/ pattern matching?

Hello, i am experimenting with the increase in register/ vector width to 64 elements of 32 bits instead of 16 in x86 backend. for eg. i have a loop with 65 iterations; if my IR generates v64i32 and 1 scalar, still the backend breaks the v64i32 into 4 v16i32. i want it to retain v64i32. like if there are 128 elements in loop then it should break it into 2 v64i32 instructions. in order to do this i

Have you read http://llvm.org/docs/WritingAnLLVMBackend.html and http://llvm.org/docs/CodeGenerator.html ? http://llvm.org/docs/WritingAnLLVMBackend.html#instruction-selector describes how to define a store instruction. -Eli On 7/6/2017 6:51 PM, hameeza ahmed via llvm-dev wrote: > Please correct me i m stuck at this point. > > On Jul 6, 2017 5:18 PM, "hameeza ahmed"

Hi List, I have start and end times of events structure(list(start = c("15:00", "15:00", "15:00", "11:00", "14:00", "14:00", "15:00", "12:00", "12:00", "12:00", "12:00", "12:00", "12:00", "12:00", "12:00", "12:00", "12:00",

Thank You. On Fri, Jul 7, 2017 at 10:03 AM, Craig Topper <craig.topper at gmail.com> wrote: > Yes, that error is from instruction selection. I think your legalization > changes worked fine. > > ~Craig > > On Thu, Jul 6, 2017 at 8:21 PM, hameeza ahmed via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> also i further run the following command;

Hi, I am having some issues with how some of the instructions are being legalized. So this is my intial basic block. The area of concern is the last three instructions. I will pick and choose debug output to keep this small. SelectionDAG has 36 nodes: t0: ch = EntryToken t6: i32,ch = CopyFromReg t0, Register:i32 %vreg507 t2: i32,ch = CopyFromReg t0, Register:i32 %vreg17

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,

But isn't kinda silly that we transform to xor and then we transform it back. What is the advantage in doing so? Also, since we do that method, I now have to introduce setcc patterns for i1 values, instead of being able to just use logical pattern operators like not. -Dilan On Fri, Jul 21, 2017 at 11:00 AM Dilan Manatunga <manatunga at gmail.com> wrote: > For some reason I

We've recently moved our project from LLVM 3.6 to LLVM 3.9. I noticed one of our code generation tests is breaking in 3.9. The test is: ; RUN: llc < %s -march=xstg | FileCheck %s define i64 @bclr64(i64 %a, i64 %b) nounwind readnone { entry: ; CHECK: bclr r1, r0, r1, 64 %sub = sub i64 %b, 1 %shl = shl i64 1, %sub %xor = xor i64 %shl, -1 %and = and i64 %a, %xor ret i64

Is there any way to get it to delay this optimization where it goes from this: Initial selection DAG: BB#0 'bclr64:entry' SelectionDAG has 14 nodes: t0: ch = EntryToken t2: i64,ch = CopyFromReg t0, Register:i64 %vreg0 t4: i64,ch = CopyFromReg t0, Register:i64 %vreg1 t6: i64 = sub t4, Constant:i64<1> t7: i64 = shl Constant:i64<1>, t6

Setting the ISD::ROTL to Expand doesn't work? (via SetOperation) You could also do a Custom hook if that's what you're looking for. On Thu, Nov 3, 2016 at 5:12 PM, Phil Tomson <phil.a.tomson at gmail.com> wrote: > ... or perhaps to rephrase: > > In 3.9 it seems to be doing a smaller combine much sooner, whereas in 3.6 > it deferred that till later in the

Thank you. i understood how avx512 vector instructions are written in x86instravx512. i need to define my vector instructions so i wrote; def VMOV_256B_RM : I<0x6F, MRMSrcMem, (outs VR2048:$dst), (ins i32mem:$src), "vmov_256B_rm\t{$src, $dst|$dst, $src}", [(set VR2048:$dst, (v64i32 (scalar_to_vector (loadi32 addr:$src))))],

One option may be to prevent the formation of ROTL, if possible, and then generating rol by hand. Marking it as "expand" would likely stop the DAG combiner from creating it. Then you could "preprocess" the selection DAG before the instruction selection and do the pattern matching yourself. -Krzysztof On 11/3/2016 4:24 PM, Phil Tomson via llvm-dev wrote: > I could try

Thank you; i have changed as follows.is it fine now? def VADD_256B : I<0xFE, MRMDestReg, (outs VR2048:$dst), (ins VR2048:$src1, VR2048:$src2), "VADD_256B\t{$src, $dst|$dst, $src}", [(set VR2048:$dst, (add VR2048:$src1, VR2048:$src2))]]>; Also here i have changed class RI to I. Does it make any difference? On Sat, Jul 8, 2017 at 9:38 AM, Craig Topper

Hi, R-users, I met a problem: Items:[Anna 'moi =) akku loppu joskus 4ltä. Kestää kauan nää..'\tAmer, Tuusula (0:20)\t20\t12\t16\t00\t00\t11]/Anne 'Ei jakoa,uus päivä muistio et 4n niin peruin. Hups'\t (0:16)\t0\t12\t18\t00\t00\t11/Elina 'Konsertissa. En tod. vastaa teille'\tEtu-Töölö, Helsinki (2:40)\t24\t12\t18\t00\t00\t11 I want to parsing the above data into the

int %nlz10(uint %param.x) { %.t3 = shr uint %param.x, ubyte 1 ; <uint> [#uses=1] %.t4 = or uint %.t3, %param.x ; <uint> [#uses=2] %.t7 = shr uint %.t4, ubyte 2 ; <uint> [#uses=1] %.t8 = or uint %.t7, %.t4 ; <uint> [#uses=2] %.t11 = shr uint %.t8, ubyte 4 ; <uint> [#uses=1]

I have the following selection DAG: SelectionDAG has 9 nodes: t0: ch = EntryToken t2: i64,ch = CopyFromReg t0, Register:i64 %vreg0 t16: i32,ch = load<LD1[%ptr](tbaa=<0x10023c9f448>), anyext from i8> t0, t2, undef:i64 t15: v16i8 = BUILD_VECTOR t16, t16, t16, t16, t16, t16, t16, t16, t16, t16, t16, t16, t16, t16, t16, t16 t11: ch,glue = CopyToReg t0, Register:v16i8 %V2, t15

Thanks Anton and Krzysztof! Here is the dump using the -debug flag. At this point I am not making much sense of this, would it be too much to ask if one of you could walk me through one of these lines? One thing that I didn't point out is that I never defined any separate floating point registers, not sure if this will pose any issue? Thanks again for your time! Jeff jeff at

I would like to revive this thread, as I am struggling a lot with the FP16 implementation in the ARM backend. My implementation in https://reviews.llvm.org/D38315 is finished (except one case), but a more robust alternative implementation was suggested. One can indeed argue that my current implementation is a bit fragile, because it involves manually patching up the isel dags for a few cases. The