remove avx2 requirement

Author: TheNumbat

README.md

@@ -17,7 +17,7 @@ git submodule add https://github.com/TheNumbat/rpp
 Then add the following lines to your CMakeLists.txt:
 
 ```cmake
-add_subdirectory(rpp)
+add_subdirectory(rpp/rpp)
 target_link_libraries($your_target PRIVATE rpp)
 target_include_directories($your_target PRIVATE "rpp")
 ```
@@ -60,10 +60,10 @@ For faster parallel builds, you can instead generate [ninja](https://ninja-build
 
 Only the following configurations are supported:
 
-| OS      | Compiler    | Arch |
-|---------|-------------|------|
-| Windows | MSVC 19.37+ | AVX2 |
-| Linux   | Clang 17+   | AVX2 |
+| OS      | Compiler    | Arch   |
+|---------|-------------|--------|
+| Windows | MSVC 19.37+ | x86_64 |
+| Linux   | Clang 17+   | x86_64 |
 
 Other configurations (macOS, aarch64, GCC, etc.) may be added in the future.
 

rpp/CMakeLists.txt

@@ -87,13 +87,13 @@ if(MSVC)
     string(REPLACE "/GR" "" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
 
     target_compile_definitions(rpp PRIVATE WIN32_LEAN_AND_MEAN NOMINMAX _HAS_EXCEPTIONS=0)
-    target_compile_options(rpp PRIVATE /arch:AVX2 /MP /W4 /GR- /GS- /EHa- /wd4201)
+    target_compile_options(rpp PRIVATE /MP /W4 /GR- /GS- /EHa- /wd4201)
 elseif(CLANG)
     if(CLANG_VERSION_MAJOR LESS 17)
         message(FATAL_ERROR "Unsupported Clang version: only 17+ is supported.")
     endif()
 
-    target_compile_options(rpp PRIVATE -mavx2 -Wall -Wextra -fno-exceptions -fno-rtti)
+    target_compile_options(rpp PRIVATE -Wall -Wextra -fno-exceptions -fno-rtti)
 else()
     message(FATAL_ERROR "Unsupported compiler: only MSVC and Clang are supported.")
 endif()

rpp/base.h

@@ -53,12 +53,6 @@
 #error "Unsupported architecture: only x64 is supported."
 #endif
 
-#ifdef __AVX2__
-#define RPP_ARCH_AVX2
-#else
-#error "Unsupported architecture: AVX2 is required."
-#endif
-
 #define null nullptr
 
 namespace rpp {

rpp/simd.h

@@ -6,6 +6,8 @@
 namespace rpp::SIMD {
 
 struct F32x4 {
+    // Assumes SSE4.2 is supported.
+
     alignas(16) f32 data[4];
 
     [[nodiscard]] static F32x4 set1(f32 v) noexcept;
@@ -27,6 +29,8 @@ struct F32x4 {
 };
 
 struct F32x8 {
+    // Assumes AVX2 is supported.
+
     alignas(32) f32 data[8];
 
     [[nodiscard]] static F32x8 set1(f32 v) noexcept;