* [style] Use same style for cmake `set` command
* [build] Specify CMAKE_FIND_ROOT_PATH_MODE_PACKAGE in xxx.toolchain.cmake
* [build] Allow user passing args for cmake find cmds

* complete abs, fmod and sin function in simplemath.h

* remove some unused variables in simplemath.cpp

* modify test-coverage.yml and add some functions to simplemath.cpp

* modify erf.cpp which included math.h

* include platform.h for NCNN_SIMPLEMATH definition

* move utility constants and functions in simplemath.h to simplemath.cpp

* guard simplemath functions with extern "C"

* add NCNN_EXPORT macro in simplemath.h

* include plateform.h and guard all declarations with NCNN_SIMPLEMATH

* clean unused code in test_unaryop.cpp

* guard #include <vector> with NCNN_SIMPLEMATH in benchncnn.cpp

* add 'static' to guard functions that not declarated in header file

* modify sin and cos with better implementation

---------

Co-authored-by: HonestDeng <HonestDeng@users.noreply.github.com>

* Add POWER8 VSX toolchains

POWER8, though slower than POWER9, is still used in the wild; these
toolchains should still be much faster on POWER8 than POWER8 without VSX
optimizations.

* VSX toolchains: set -cpu arg in QEMU CI tests

Improves compatibility with Clang 11.

Also rename NCNN_SSE* options to NCNN_VSX_SSE* to avoid conflict between
x86 and POWER (went unnoticed before because x86 doesn't have an option
for toggling SSE 4.1).

Co-authored-by: Jeremy Rand <jeremyrand@danwin1210.de>

* Add POWER9 VSX toolchains

Translating x86_64 SSE to ppc64le VSX intrinsics yields a quite large
speedup on POWER9. See this article for background:

https://www.talospace.com/2019/07/easier-power-vectorizing-for-fun-and.html

* Add power9le docs

* power9le clang toolchain: Document Clang 13+ requirement

---------

Co-authored-by: Jeremy Rand <jeremyrand@danwin1210.de>

* RVV: use size_t for vl

* RVV: replace vsseg.v tuple type by using regex

-----

search:
vsseg([1-9])e(8|16|32)_v_(f|i|u)\2m(1|2|4|8)x\1\(([ -~]+), vcreate_\3\2m\4x\1\(([ -~]+)\), vl\);

substitute by:
vsseg$1e$2_v_$3$2m$4($5, $6, vl);

* RVV: replace vssseg.v tuple types by using regex

---

search:
vssseg([1-9])e(8|16|32)_v_f\2m1x\1\(([ -~]+), vcreate_f\2m1x\1\(([ -~]+)\), vl\);

substitute by:
vssseg$1e$2_v_f$2m1($3, $4, vl);

* RVV: replace vlseg.v tuple types in load/store

* RVV: replace vloxseg2ei32.v tuple types

* RVV: add a wrapper for old compilers

* RVV: add segment load/store wrapper in pakcing

* RVV: fix cmake test

* RVV: make clang happy by dropping VLAs in sgemm

* RVV: add clang cmake toolchain configure

* RVV: add clang ci, riscv64-unknown-linux-gnu

Co-authored-by: thelastlin <thelastlin@users.noreply.github.com>
Co-authored-by: nihui <shuizhuyuanluo@126.com>

* armv7 vfpv4 infrastructure
* optional fp16 format ieee
* arm neon assembly optimization for cast fp16/bf16

* RVV: follow intrinsic doc, vfredusum -> vfredsum

* C906: change toolchains for vfredusum

* RVV: test compiler for vfredusum_vs_*

* Support Ingenic X2000 & T40

T40 claimed to have MIPS32R2 with MSA, but tested not working on my unit, so set to mips32r2 without MSA.

* Add Ingenic T40XP benchmark result

Co-authored-by: tsuibin <tsuibin@loongson.cn>

* fix iOS minimum version,when used Vukan 1.2
* Update IOS mininum version to 9.0

* SSE2: BatchNorm

* Fixed batch norm in AVX configuration

* Optimized register size switch

* Attempt to pass CI

* Attempt to pass CI

* Bias op

* Element wise ops

* Support packing on x86 by default

* Fixed macro range in bias

* Use aligned read for packed data

* Update testutil.h

* Update pooling_x86.cpp

* Support wasn SIMD

* Fix emscripten compiler flags

* fix build

* more ci fix

* concat x86 pack4

* flatten x86 pack4

* more x86 pack4

* ci pass

* fix

* enable sse2 mathfun

* enable --experimental-wasm-simd

Co-authored-by: nihui <shuizhuyuanluo@126.com>
Co-authored-by: nihuini <nihuini@tencent.com>

Test platform: ZYNQ 7020, there is vfpv3 but isn't vfpv4

* [build] add toolchain file w/o stdcxx dependency

* [build] link m and gcc lib explicitly

* [ncnn] complete simple stl impl

* [ncnn] adapt for ncnn simplestl

* [test] adapt for ncnn simplestl

* [ncnn] fix missing algorithm and list when simplestl disabled

* [ncnn] fix guard for operator new and delete

* [style] fix the code style

* [build] fix build failed on darwin and emscripten

* [ci] do not import cxx to avoid operator conflict

* [ncnn] add temporary partial_sort impl using bubble sort

heap sort should be used for better perf.

* [ncnn] add std greater and less function

* [ncnn] fix placement new operator overload

* [ncnn] add operator delete with size info

* [build] disable exception, rtti, example and tools when simplestl on

* [build] add toolchain for arm simplestl

* [build] add toolchain for aarch64 simplestl

* [ncnn] move initializer to constructor

* [ncnn] use deteiled type instead of auto

* [ncnn] use plain lib name in target_link_libraries