chore: import upstream snapshot with attribution

cmake/checks/cpu_rvv.cpp

@@ -0,0 +1,37 @@
+#include <stdio.h>
+
+#if !defined(__riscv) || !defined(__riscv_v)
+#error "RISC-V or vector extension(RVV) is not supported by the compiler"
+#endif
+
+#if !defined(__THEAD_VERSION__) && defined(__riscv_v_intrinsic) && __riscv_v_intrinsic < 12000
+#error "Wrong intrinsics version, v0.12 or higher is required for gcc or clang"
+#endif
+
+#include <riscv_vector.h>
+
+#ifdef __THEAD_VERSION__
+int test()
+{
+    const float src[] = { 0.0f, 0.0f, 0.0f, 0.0f };
+    uint64_t ptr[2] = {0x0908060504020100, 0xFFFFFFFF0E0D0C0A};
+    vuint8m1_t a = vreinterpret_v_u64m1_u8m1(vle64_v_u64m1(ptr, 2));
+    vfloat32m1_t val = vle32_v_f32m1((const float*)(src), 4);
+    return (int)vfmv_f_s_f32m1_f32(val);
+}
+#else
+int test()
+{
+    const float src[] = { 0.0f, 0.0f, 0.0f, 0.0f };
+    uint64_t ptr[2] = {0x0908060504020100, 0xFFFFFFFF0E0D0C0A};
+    vuint8m1_t a = __riscv_vreinterpret_v_u64m1_u8m1(__riscv_vle64_v_u64m1(ptr, 2));
+    vfloat32m1_t val = __riscv_vle32_v_f32m1((const float*)(src), 4);
+    return (int)__riscv_vfmv_f_s_f32m1_f32(val);
+}
+#endif
+
+int main()
+{
+  printf("%d\n", test());
+  return 0;
+}