Add simd utils

Author: XapaJIaMnu

.gitmodules

@@ -23,3 +23,6 @@
 [submodule "src/3rd_party/ruy"]
 	path = src/3rd_party/ruy
 	url = https://github.com/google/ruy.git
+[submodule "src/3rd_party/simd_utils"]
+	path = src/3rd_party/simd_utils
+	url = https://github.com/JishinMaster/simd_utils.git

src/3rd_party/CMakeLists.txt

@@ -9,7 +9,7 @@ add_subdirectory(./faiss)
 include_directories(./faiss)
 
 if(COMPILE_CPU)
-  if((NOT ARM) AND (NOT GENERATE_MARIAN_INSTALL_TARGETS))
+  if((NOT ${CMAKE_TARGET_ARCHITECTURE_CODE} MATCHES "arm") AND (NOT GENERATE_MARIAN_INSTALL_TARGETS))
     set(INTGEMM_DONT_BUILD_TESTS ON CACHE BOOL "Disable intgemm tests")
     add_subdirectory(./intgemm)
   endif()

src/3rd_party/simd_utils

@@ -91,12 +91,7 @@ inline void GemmRuy(const bool transA,
     }
 
   } else {
-    // @jerinphilip has not yet been able to find a ruy primitive that does in
-    // place addition to obtain full gemm.
-    //
-    // Safe bet is to make an additional allocation to store the result of
-    // multiply  and use the existing values in C.
-    //
+    // No multiply-add in Ruy
     // See also: https://github.com/google/ruy/issues/307
 
     AlignedVector<float> intermediate(M * N);