Displaying 20 results from an estimated 200 matches similar to: "Node deletion during DAG Combination ?"
2017 Oct 13
2
[SelectionDAG] Assertion due to MachineMemOperand flags difference.
Hello,
I've hit an assertion in SelectionDAG where we try to merge 2 loads
that have the same operands but their MMO flags differ. One is
dereferenceable and one is not. I'm not sure what the underlying issue
here is:
1) MDSDNode with the same operands should have the same flags set on
their respective MMO. The fact the flags differ when the
opcode,types,operands and address-space are
2019 Dec 09
2
[PATCH] D70246: [InstCombine] remove identity shuffle simplification for mask with undefs
Sanjay,
I'm looking at some missed optimizations caused by D70246. Here's a test case:
define <4 x float> @f(i32 %t32, <4 x float>* %t24) {
.entry:
%t43 = insertelement <3 x i32> undef, i32 %t32, i32 2
%t44 = bitcast <3 x i32> %t43 to <3 x float>
%t45 = shufflevector <3 x float> %t44, <3 x float> undef, <4 x i32>
<i32 0, i32 undef,
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
2017 Feb 28
2
rL296252 Made large integer operation codegen significantly worse.
I see we're missing an isel pattern for add producing carry and doing a
memory RMW. I'm going to see if adding that helps anything.
~Craig
On Mon, Feb 27, 2017 at 8:47 PM, Nirav Davé via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Yes. I'm seeing that as well. Not clear what's going on.
>
> In any case it looks to be unrelated to the alias analysis so barring
2018 May 04
2
How to constraint instructions reordering from patterns?
Hi,
Is there a kind of scope mechanism in the instruction lowering pattern language in order to control where instructions are inserted or how they are later reordered during the SelectionDiag linearization?
I know the glue chain that stick instructions together. But such mechanism in not provided in instruction lowering pattern.
I'm facing many situations where some patterns are lowered into
2018 May 04
2
How to constraint instructions reordering from patterns?
The DAG dumping will try to print some of the nodes "inline" (i.e. where
they are used) to make the output more readable, so the dump of the DAG
may not strictly reflect the node ordering.
-Krzysztof
On 5/4/2018 8:18 AM, Dominique Torette via llvm-dev wrote:
> Here is a last example to illustrate my concern.
>
> The problem is about the lowering of node t13.
>
>
2018 May 04
0
How to constraint instructions reordering from patterns?
Here is a last example to illustrate my concern.
The problem is about the lowering of node t13.
Initial selection DAG: BB#0 '_start:entry'
SelectionDAG has 44 nodes:
t11: i16 = Constant<0>
t0: ch = EntryToken
t3: ch = llvm.clp.set.rspa t0, TargetConstant:i16<392>, Constant:i32<64>
t5: ch = llvm.clp.set.rspb t3,
2018 May 04
0
How to constraint instructions reordering from patterns?
Krzysztof,
Thanks for your interest to my questions.
In order to clarify the context, here is the C source file of my test case.
The 3 builtins initialize some stack pointers. They have to be executed before any other instruction.
extern float fdivfaddfmul_a(float a, float b, float c, float d);
volatile static float x1,x2,x3,x4;
void _start(void)
{
float res;
2017 Sep 20
1
Store lowering -> Cannot select FrameIndex.
Hi,
I'm try to lower the store LLVM-IR instruction as per the following LLVM IR program:
*** IR Dump After Module Verifier ***
define void @storeloadi32() {
%ptr = alloca i32
store volatile i32 12, i32* %ptr
ret void
}
The target instruction is associated to the store like this:
def MOVSUTO_A_iSLr : CLPFPU_A_iSLr<0b1000001101,
2016 Jul 30
1
Instruction selection bug for vector store with FixedStack
Hello.
Could you please help me solve the following LLC bug happening at instruction
selection time:
ISEL: Starting pattern match on root node: t172: ch = store<ST64[FixedStack6]>
t0, t6, FrameIndex:i64<6>, undef:i64
Initial Opcode index to 157
Skipped scope entry (due to false predicate) at index 162, continuing at 236
Match failed at
2017 Feb 11
2
Specify special cases of delay slots in the back end
Hello.
Hal, the problem I have is that it doesn't advance at the next available instruction
- it always gets the same store. This might be because I did not specify in a file like
[Target]Schedule.td the functional units, processor and instruction itineraries.
Regarding the Stalls argument to my method
[Target]DispatchGroupSBHazardRecognizer::getHazardType() I always get the
2017 Aug 06
2
VBROADCAST Implementation Issues
i want to implement gather for v64i32. i wrote following code.
def GATHER_256B : I<0x68, MRMSrcMem, (outs VR_2048:$dst), (ins
i2048mem:$src),
"GATHER_256B\t{$src, $dst|$dst, $src}",
[(set VR_2048:$dst, (v64i32 (masked_gather
addr:$src)))],
IIC_MOV_MEM>, TA;
def: Pat<(v64f32 (masked_gather addr:$src)), (GATHER_256B
2017 Aug 07
2
VBROADCAST Implementation Issues
Hello,
I did as you said,
Please tell me whether the following correct now??
def GATHER_256B : I<0x68, MRMSrcMem, (outs VR_2048:$dst, _.KRCWM:$mask_wb),
(VR_2048:$src1, _.KRCWM:$mask, ins i2048mem:$src2),
"GATHER_256B\t{$src2, {$dst}{${mask}}|${dst} {${mask}},
$src2}"),
[(set VR_2048:$dst, _.KRCWM:$mask_wb, (v64i32
(GatherNode
2017 Aug 07
3
VBROADCAST Implementation Issues
Thank You. Still getting errors.I have modified my instructions as you said
as follows:
def GATHER_256B : I<0x68, MRMSrcMem, (outs VR_2048:$dst, VK64WM:$mask_wb),
(ins VR_2048:$src1, VK64WM:$mask, i2048mem:$src2),
"GATHER_256B\t{$src2, {$dst} {${mask}}|${dst}
{${mask}}, $src2}",
[(set VR_2048:$dst, VK64WM:$mask_wb, (v64i32
(masked_gather
2002 Dec 26
3
Win98 clients not 'seeing' each other
Hi there,
I have a somewhat wide experience with samba. I've succesfully installed
it as a client as well as a PDC on Windows networks.
The last time, however, there has been an issue with the win9x stations.
I've setup the Samba server over Linux to act as a PDC for the domain. I
use dhcp to assign the network configuration to the hosts, and the only
protocol installed on them is
2018 Mar 29
4
Mapping virtual registers to physical registers
Hi,
In the context of MachineCode custom inserter, I'm trying to enforce the mapping of virtual register to a physical one.
According to the documentation https://llvm.org/docs/CodeGenerator.html#mapping-virtual-registers-to-physical-registers
There are two ways: the direct one and the indirect ones. The indirect ones refer VirtRegMap class that I've never found. So I tried the direct
2017 Jul 27
2
Are there some strong naming conventions in TableGen?
Hi,
For the development of a new micro-controller backend, I try to lowering the following store SDNode: t5: ch = store<ST2[%ptr2](align=4)> t0, Constant:i16<3>, FrameIndex:i16<1>, undef:i16
I have defined the following instruction and associated DAG pattern.
def MOVSUTO_A_i32o : CLPFPU_A_i32o_Inst<0b1000001101,
2018 Mar 27
1
Live Interval Analysis and pipelining.
Hi,
I'm writing a backend for a proprietary microcontroller.
I'm facing a limitation related to Live Interval Analysis.
Some FPU instructions, most notably the FDIV, requires a few cycles to complete.
There is a pipeline and, during the execution of the FDIV, others instructions could be executed in parallel, provided they don't use the same registers.
This pipeline has been modeled
2018 Mar 30
0
Mapping virtual registers to physical registers
Hi again,
After further investigation, I've found that the private PhysRegUseDefLists array ("head of use/def list for physical register") from MachineRegisterInfo class seems to be empty.
But I didn't found any methods for updating such data structure. How/where this "use/def list" should be managed ?
Is the documentation
2017 Jul 24
2
How to lower a 'Store' node using the list<dag> pattern.
Hi,
I'm trying to complete the lowering for a new microcontroller. I'm using LLVM 3.8.
For now this lowering crashes on 'Store' node, which is actually not yet defined.
I've tried to map the ISel 'Store' node to architecture specific instructions.
I've define the following semantic to my architecture specific instructions:
def MOVSUTO_SU_rr :