Displaying 20 results from an estimated 1000 matches similar to: "Instruction selection gives "LLVM ERROR: Cannot select""
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
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 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
2006 May 05
2
[LLVMdev] ExecutionEngine blew the stack ?
Segfault in EE->getPointerToFunction.
I think it's blown the stack, gdb reports a never ending backtrace (below).
I generate llvm assembly and parse/verify OK.
Attached is the assembly. It is the smallest example
generated that causes the segfault.
If this EE uses a recursive function (??), it seems an inherent limitation
in how big llvm functions can be.
Simon.
gdb backtrace:
#0
2007 Mar 01
2
[LLVMdev] Version 1.9 SSA form question
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]
2018 Apr 09
1
llvm-dev Digest, Vol 166, Issue 22
Hi Krzysztof,
Sure, please see below. DAG.dump.() before and after, annotated with what I
believe the DAG means.
I've spent some time debugging the method but it's proving difficult to
determine where the logic is misfiring. Disabling the entire combine causes
a lot of failing x86-64 tests - I may have to learn an upstream vector ISA
to make progress on this.
Thank you
>From your
2017 Sep 14
2
Question about 'DAGTypeLegalizer::SplitVecOp_EXTRACT_VECTOR_ELT'
Hi All,
I have a question about splitting 'EXTRACT_VECTOR_ELT' with 'v2i1'. I
have a llvm IR code snippet as following:
llvm IR code snippet:
for.body: ; preds = %entry,
%for.cond
%i.022 = phi i32 [ 0, %entry ], [ %inc, %for.cond ]
%0 = icmp ne <2 x i32> %vecinit1, <i32 0, i32 -23>
%1 = extractelement <2 x i1>
2007 Jan 14
0
[LLVMdev] Request documentation for global var syntax
On Thu, 11 Jan 2007, Schimmel, Mark wrote:
> file://docs/LangRef.html#globalvars
>
> The section describing the definition of global vars discusses that you
> can specify an alignment and can also specify a section. Could someone
> provide an example that works in gccas in release 1.9 for both defining
> which section the var is assigned to and defining the variables
>
2017 Sep 15
2
Question about 'DAGTypeLegalizer::SplitVecOp_EXTRACT_VECTOR_ELT'
> extends the elements to 8bit and stores them on stack.
Store is responsible for zero-extend. This is the policy...
- Elena
-----Original Message-----
From: jingu at codeplay.com [mailto:jingu at codeplay.com]
Sent: Friday, September 15, 2017 17:45
To: llvm-dev at lists.llvm.org; Demikhovsky, Elena <elena.demikhovsky at intel.com>; daniel_l_sanders at apple.com
Subject: Re: Question
2018 Mar 15
1
[SelectionDAG] DbgValue nodes aren't transferred
> On Mar 14, 2018, at 7:55 PM, Se Jong Oh <sejooh at microsoft.com> wrote:
>
> Hi Jonas,
>
> Thanks for taking a look! It makes linear-dbg-value.ll pass for my target by producing DEBUG_VALUEs correctly. I also tried a simple function with few operations and confirmed DEBUG_VALUEs which are not produced without trasferDbgValues in SetPromotedInteger.
That’s great news! Do
2007 Jan 11
3
[LLVMdev] Request documentation for global var syntax
file://docs/LangRef.html#globalvars
The section describing the definition of global vars discusses that you
can specify an alignment and can also specify a section. Could someone
provide an example that works in gccas in release 1.9 for both defining
which section the var is assigned to and defining the variables
alignment?
Also, is there another document that describes how you define sections
2018 Apr 30
0
[SelectionDAG] DbgValue nodes aren't transferred
Hi Jonas,
I have another case that DBG_VALUE is not produced. I would appreciate it if you could take a quick look at the testcase below.
test code:
llc -mtriple=aarch64 -stop-after=livedebugvalues -o - test.ll
; Function Attrs: nounwind ssp uwtable
define void @f() #0 !dbg !4 {
entry:
tail call void @h(i16 0) #2, !dbg !14
%call = tail call i16 (...) @g() #2, !dbg !15
tail call void
2017 Sep 17
2
Question about 'DAGTypeLegalizer::SplitVecOp_EXTRACT_VECTOR_ELT'
Please open a bugzilla ticket and attach your testcase. It will allow us to debug and fix the problem.
Thanks
- Elena
From: JinGu [mailto:jingu at codeplay.com]
Sent: Saturday, September 16, 2017 00:38
To: Demikhovsky, Elena <elena.demikhovsky at intel.com>; daniel_l_sanders at apple.com <daniel_l_sanders at apple.com>; Jon Chesterfield <jonathanchesterfield at
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
2018 Apr 30
2
[SelectionDAG] DbgValue nodes aren't transferred
> On Apr 30, 2018, at 1:49 PM, Se Jong Oh <sejooh at microsoft.com> wrote:
>
> Hi Jonas,
>
> I have another case that DBG_VALUE is not produced. I would appreciate it if you could take a quick look at the testcase below.
>
>
> test code:
>
> llc -mtriple=aarch64 -stop-after=livedebugvalues -o - test.ll
>
> ; Function Attrs: nounwind ssp uwtable
>
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
2018 Apr 09
2
A way to opt out of a dag combine?
Is there an established way of disabling a DAG combine on a per target
basis, where it appears to be detrimental to the generated code? Writing if
(!mytarget) in DAGCombiner.cpp works but tends to be erased by git merge
and generally doesn't look ideal. Writing the inverse transform in target
specific code doesn't work in this instance and in general creates an
infinite loop.
Guidance
2019 Jul 11
6
Glue to connect two nodes in LLVM backend
Hello everyone,
I wanted to attach a node without affecting the present nodes in any way. I
tried to use MVT::Glue for that but I think I'm missing something as I
could not achieve the below state.
LUI LUI
| |
ADDI ----GLUE---- ADDI
|
store
I've few question about this and Glue node in general, I'll be happy to get
some help on
2018 Mar 14
2
[SelectionDAG] DbgValue nodes aren't transferred
Hi Jonas,
Thanks for taking a look! It makes linear-dbg-value.ll pass for my target by producing DEBUG_VALUEs correctly. I also tried a simple function with few operations and confirmed DEBUG_VALUEs which are not produced without trasferDbgValues in SetPromotedInteger.
Thanks,
Sejong
From: jdevlieghere at apple.com <jdevlieghere at apple.com>
Sent: Wednesday, March 14, 2018 4:07 AM
To: Se
2017 Sep 18
1
Question about 'DAGTypeLegalizer::SplitVecOp_EXTRACT_VECTOR_ELT'
> so I think we need to use non-extending load for element size less than 8bit on "DAGTypeLegalizer::SplitVecOp_EXTRACT_VECTOR_ELT" like this roughly.
> if (N->getOperand(0).getValueType().getVectorElementType().getSizeInBits() < 8) {
> return DAG.getLoad(N->getValueType(0), dl, Store, StackPtr, MachinePointerInfo());
> } else {
> return