Add wasi support (#5534)

* benchmark: Don't use std::thread when NCNN_THREADS is OFF

* Add wasi support

cmake -B build -DCMAKE_BUILD_TYPE=Release \
	--toolchain ${wasi_sdk}/share/cmake/wasi-sdk.cmake \
	-DNCNN_RUNTIME_CPU=OFF \
	-DNCNN_DISABLE_EXCEPTION=ON \
	-DNCNN_THREADS=OFF

cmake --build build

After build, you can run benchncnn on cmdline with wasmtime:
wasmtime --dir . benchncnn

CMakeLists.txt

@@ -559,7 +559,7 @@ else()
         unset(CMAKE_REQUIRED_FLAGS)
     endif()
 
-    if(NOT CMAKE_SYSTEM_NAME STREQUAL "Emscripten" AND NCNN_COMPILER_SUPPORT_X86_AVX)
+    if(NOT CMAKE_SYSTEM_NAME MATCHES "Emscripten|WASI" AND NCNN_COMPILER_SUPPORT_X86_AVX)
         option(NCNN_AVX "optimize x86 platform with avx extension" ON)
         if(NCNN_COMPILER_SUPPORT_X86_FMA)
             if(NCNN_AVX)

src/CMakeLists.txt

@@ -395,8 +395,10 @@ if(NCNN_TARGET_ARCH STREQUAL "x86")
             endif()
             target_compile_options(ncnn PRIVATE /D__SSE2__)
         else()
-            target_compile_options(ncnn PRIVATE -msse2 -msse)
-            if(CMAKE_SYSTEM_NAME STREQUAL "Emscripten")
+            if(NOT CMAKE_SYSTEM_NAME MATCHES "WASI")
+                target_compile_options(ncnn PRIVATE -msse2 -msse)
+            endif ()
+            if(CMAKE_SYSTEM_NAME MATCHES "Emscripten|WASI")
                 target_compile_options(ncnn PRIVATE -msimd128)
             endif()
         endif()

src/benchmark.cpp

@@ -15,19 +15,27 @@
 #include "benchmark.h"
 
 #if (__cplusplus >= 201103L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201103L)) && !defined(__riscv) && !NCNN_SIMPLESTL
+#define USE_CXX11_CLOCK 1
+#else
+#define USE_CXX11_CLOCK 0
+#endif
+
+#if USE_CXX11_CLOCK
 #include <chrono>
+#if NCNN_THREADS
 #include <thread>
+#endif
 #include <numeric>
 #include <algorithm>
-#else
+#endif // USE_CXX11_CLOCK
+
 #ifdef _WIN32
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #else                 // _WIN32
 #include <sys/time.h> //gettimeofday()
 #include <unistd.h>   // sleep()
 #endif                // _WIN32
-#endif
 
 #if NCNN_BENCHMARK
 #include "layer/convolution.h"
@@ -46,7 +54,7 @@ namespace ncnn {
 
 double get_current_time()
 {
-#if (__cplusplus >= 201103L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201103L)) && !defined(__riscv) && !NCNN_SIMPLESTL
+#if USE_CXX11_CLOCK
     auto now = std::chrono::high_resolution_clock::now();
     auto usec = std::chrono::duration_cast<std::chrono::microseconds>(now.time_since_epoch());
     return usec.count() / 1000.0;
@@ -69,7 +77,7 @@ double get_current_time()
 
 void sleep(unsigned long long int milliseconds)
 {
-#if (__cplusplus >= 201103L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201103L)) && !defined(__riscv) && !NCNN_SIMPLESTL
+#if USE_CXX11_CLOCK && NCNN_THREADS
     std::this_thread::sleep_for(std::chrono::milliseconds(milliseconds));
 #else
 #ifdef _WIN32

src/cpu.cpp

@@ -17,8 +17,10 @@
 #include "platform.h"
 
 #include <limits.h>
+#ifndef __wasi__
 #include <setjmp.h>
 #include <signal.h>
+#endif // __wasi__
 #include <stdio.h>
 #include <string.h>