* improve nms

* add back get_valid_count syncs

* init impl for topk

* Fix cpu for topk

* init cuda impl for topk

* Add cuda for topk

* fix

* Add doc

* update doc

* lint

* lint

* lint

* x

* fix warning

* [Relay] Add TopK in tf converter

* Add frontend converter

* fix

* [Relay][Docs] Add parser dependency install instructions.

See https://discuss.tvm.ai/t/trouble-enabling-antlr/2783.

* Add a word.

* Update since the parser will now be committed to the repo.

* revert b/c adding the parser doesn't fix this

* [Bugfix] [VTA] VTA DRAM Have A Logic Issue May Cause GEMM Output Wrong.

Symptom:
after change “LOG_BLOCK_IN” and “LOG_BLOCK_OUT” from vta_config.json
into 7, run vta "Simple Matrix Multiply" in "simulator", the vta
calculate result for GEMM is wrong.

Sometime VTA crash with error “Check failed: phy_addr != 0 (0 vs. 0) :
trying to get address that is nullptr”

Analysis:
Simulator hardcode kPageSize into 1<<12 and physical address calculate
based on this size, when doing “insn->dram_base” calculation , because
GetElemBytes(dst_memory_type) larger than page size, different physcial
address may get same dram_base, than caused logic issue and finally
trigger GEMM out put is wrong.

Solution:
add logic to check if PAGE SIZE larger then "GetElemBytes" return value.

* address review comments.

* annotate using visitor

* retrigger CI

* [Bugfix][VTA] PkgConfig cause crash in PYNQ board due to link library
not exist.

Symptom:
When run vta_get_started.py with pynq board, host crash and
complain "cannot find -lsds_lib" and "cannot find -l:libdma.so"

Reproduce:
At pynq board, delete the ./build/vta_config.json, then run rpc
server.
In host machine run vta_get_started.py, issue would reproduce.

Analysis:
This issue caused by 'PkgConfig' function  still using pynq2.1
library which not exist in pynq2.4 anymore, when a "reconfig_runtime"
logic of rpc_server.py get triggered , the compile would failed due to
link library not exist.

Solution:
change the link library to libcma.so.

* [Document Change][VTA] Change pynq version from 2.3 into 2.4.

Issue:
pynq 2.3 image not available anymore from pynq download page and pynq
2.4 is the current latest image which available in the said website, after
verification, currently VTA work good with pynq 2.4 image, hence update
related document from pynq 2.3 to 2.4.

Currently, the BindVar function does not take Var type into account. This causes
two same graph structures with different var shapes to have same hash.
Structural hash is used for keeping track of which operators we have
already compiled. Because of this, two operators with different shapes end up
pointing to same compiled code. The failure is encountered at runtime, where the
expected input shape asserts are not met.

* Add graph tuning

* Add tests

* Fix tests

* Fix pylint

* Small fix for docstring

* Minor fix

* Support fetching workload from relay expr

* Simplify benchmark layout transformation

* Add relay support

* Fix infer layout func name

* Refactor internal data representation

* Fix issues

* Add PBQP solver

* Fix layout transform check

* Add PBQPTuner test

* Fix lint

* Update tutorial

* Fix tutorial

* Fix lint

* Add relay test

* Remove nnvm since nnvm graph can be converted to relay function

* Modify benchmark layout wrt new layout_transform api

* Fix lint

* Update docstring for DP tuner

* Refactor traverse graph

* Support graph tuning for multiple target operators

* Fix fetching workloads

* Add x86 depthwise_conv2d infer_layout

* Fix x86 depthwise_conv2d autotvm

* Fix PBQP tuner

* Fix DP tuner

* Generate dummy layout transform record

* Update tutorial

* Modify layout records name

* Add ASF header

* Add ASF header for testing files

* Fix test

* Fix topi fetching

* Some refactors

* Fix lint

* Fix tutorial

* Rename test files

* Fix doc typo

* Add test case note link

Issue:
Once change LOG_BLOCK_IN or LOG_BLOCK_OUT into > 4 value, when run vta
“Simple Matrix Multiply” or load vta, vta would crash at vta_conv2d.py.

Analysis:
This issue caused by resnet18 logic of vta_conv2d.py which have
in_filter minmum size that is 16. > 4 value would cause such in_filter
check failed then make xfer_size be empty and find_schedules function
return a empty list finally cause crash.

Solution:
add the empty list check.

This was a typo in the original custom datatypes PR.

[VTA][TSIM] Use Module instead of RawModule for testbench by creating an empty bundle for the IO (#3242)

* use Module instead of RawModule for testbench by creating an empty bundle for the IO

* change default back to verilog

* [Doc][Relay] Add VM doc

* Add Apache header

* Apply suggestions from code review

Co-Authored-By: Steven S. Lyubomirsky <slyubomirsky@gmail.com>
Co-Authored-By: 雾雨魔理沙 <lolisa@marisa.moe>
Co-Authored-By: Logan Weber <36520469+weberlo@users.noreply.github.com>
Co-Authored-By: Zhi <5145158+zhiics@users.noreply.github.com>

* Junru's comment

* More fix

* More fix

* More fix

* last fix

* Apply suggestions from code review

Co-Authored-By: 雾雨魔理沙 <lolisa@marisa.moe>

* Apply suggestions from code review

Co-Authored-By: Logan Weber <36520469+weberlo@users.noreply.github.com>

* Add code links

* Remove unused bp

* Update docs/dev/virtual_machine.rst

Co-Authored-By: Logan Weber <36520469+weberlo@users.noreply.github.com>

* Explain TODO

* Yong's comment

Co-Authored-By: Yong Wu <55wuyong@163.com>

* Comment

* [ARITH] Improve div/mod in rewrite simplifier

* Fix lint error

* Fuller file name in src/arithmetic/modular_set.h

Co-Authored-By: Wei Chen <ipondering.weic@gmail.com>

* Generalize some rules

* Replace gcd factoring with specialized rules

* Mark rules that don't work for non-truncated division

* More tests

* Add Crop op converter

* lint

* x

* Fixed a typo

* Remove outdated url link.

* [RELAY]Frontend darknet

* CI test file updated & CI error fixed

* avg_pool pad fix

* Changed repo_url and doc formatting

* Update add_asf_header.py

* Update add_asf_header.py

Modified pick best to accumulate the best configurations from both the input and output file. (#3225)