similar to: rotl: undocumented LLVM instruction?

Displaying 20 results from an estimated 1000 matches similar to: "rotl: undocumented LLVM instruction?"

2016 Nov 03
2
rotl: undocumented LLVM instruction?
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
2016 Nov 03
3
rotl: undocumented LLVM instruction?
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
2016 Nov 03
2
rotl: undocumented LLVM instruction?
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
2017 Jul 21
4
Issue with DAG legalization of brcond, setcc, xor
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
2017 Jul 20
3
Issue with DAG legalization of brcond, setcc, xor
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
2017 Jul 07
2
Error in v64i32 type in x86 backend
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. > >
2017 Jul 06
2
Error in v64i32 type in x86 backend
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
2016 Jun 22
2
LLVM Backend Issues
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
2016 Jun 21
3
LLVM Backend Issues
Hi, I am having issues running a new backend that I created for a new architecture. I suspect these errors may have something to do with how I have the string setup in LLVMTargetMachine() below? Also - It would be great if someone could point me to a document that describes some of these error messages? For example what does t26 ..t4 mean? Thanks in advance for taking your valuable time to help
2017 Jul 07
2
Error in v64i32 type in x86 backend
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;
2017 Jul 07
2
Error in v64i32 type in x86 backend
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
2017 Jul 08
2
Error in v64i32 type in x86 backend
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:$src))))],
2017 Jul 08
5
Error in v64i32 type in x86 backend
Thank You. I have seen the opcode is 8 bits and all the combinations are already used in llvm x86. Now what to do? On Sat, Jul 8, 2017 at 10:57 AM, Craig Topper <craig.topper at gmail.com> wrote: > Yes its an opcode conflict. You'll have to look through Intel documents > and find an unused opcode. I've only added instructions based on a real > spec so I don't know
2017 Jul 08
2
Error in v64i32 type in x86 backend
Thank you; i have changed as follows.is it fine now? def VADD_256B : I<0xFE, MRMDestReg, (outs VR2048:$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
2016 Aug 02
2
Instruction selection problems due to SelectionDAGBuilder
Hello. I'm having problems at instruction selection with my back end with the following basic-block due to a vector add with immediate constant vector (obtained by vectorizing a simple C program doing vector sum map): vector.ph: ; preds = %vector.memcheck50 %.splatinsert = insertelement <8 x i64> undef, i64 %i.07.unr, i32 0
2016 Dec 14
2
Call for testing: OpenSSH 7.4
On Tue, Dec 13, 2016 at 06:22:41PM -0700, The Doctor wrote: > On Wed, Dec 14, 2016 at 12:12:21PM +1100, Damien Miller wrote: > > On Tue, 13 Dec 2016, The Doctor wrote: > > > > > Got you. Will run make tests. So far running on > > > FreeBSD 11.0 using openssl 1.0.2 current > > > > Thanks! > > Point of concern > > run test sftp-perm.sh
2016 Feb 04
2
llc gives Segmentation fault at instruction selection [was Re: Instruction selection gives "LLVM ERROR: Cannot select"]
Hello, Tim, Thank you for your advice. Indeed, the problem with "LLVM ERROR: Cannot select" was a false predicate that should have been true. I solved the problem by simply making the C++ function implementing the TableGen predicate used in my store instruction (very similar to the selectIntAddrMSA predicate from the Mips back end) return true instead of false. But
2017 Dec 06
2
[RFC] Half-Precision Support in the Arm Backends
Thanks a lot for the suggestions! I will look into using vld1/vst1, sounds good. I am custom lowering the bitcasts, that's now the only place where FP_TO_FP16 and FP16_TO_FP nodes are created to avoid inefficient code generation. I will double check if I can't achieve the same without using these nodes (because I really would like to get completely rid of them). Cheers, Sjoerd.
2019 Feb 08
2
Unfolded additions of constants after promotion of @llvm.ctlz.i16 on SystemZ
Hi, SystemZ supports @llvm.ctlz.i64() natively with a single instruction (FLOGR), and lesser bitwidth versions of the intrinsic are promoted to i64. For some reason, this leads to unfolded additions of constants as shown below: This function: define i16 @fun(i16 %arg) {   %1 = tail call i16 @llvm.ctlz.i16(i16 %arg, i1 false)   ret i16 %1 } ,gives this optimized DAG as input to instruction
2019 Jun 05
2
Strange behaviour of post-legalising optimisations(?)
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,