vendor: OpenCV 5.0.0 snapshot at 40738fb16ceddb5fb3fea747585f7ce6abb0605b

cmake/checks/cpu_neon_bf16.cpp

@@ -0,0 +1,46 @@
+#if (defined __GNUC__ && (defined __arm__ || defined __aarch64__)) || (defined _MSC_VER && (defined _M_ARM64 || defined _M_ARM64EC))
+#include <stdio.h>
+#include "arm_neon.h"
+
+/*#if defined __clang__
+#pragma clang attribute push (__attribute__((target("bf16"))), apply_to=function)
+#elif defined GCC
+#pragma GCC push_options
+#pragma GCC target("armv8.2-a", "bf16")
+#endif*/
+bfloat16x8_t vld1q_as_bf16(const float* src)
+{
+    float32x4_t s0 = vld1q_f32(src), s1 = vld1q_f32(src + 4);
+    return vcombine_bf16(vcvt_bf16_f32(s0), vcvt_bf16_f32(s1));
+}
+
+void vprintreg(const char* name, const float32x4_t& r)
+{
+    float data[4];
+    vst1q_f32(data, r);
+    printf("%s: (%.2f, %.2f, %.2f, %.2f)\n",
+        name, data[0], data[1], data[2], data[3]);
+}
+
+void test()
+{
+    const float src1[] = { 1.f, 2.f, 3.f, 4.f, 5.f, 6.f, 7.f, 8.f };
+    const float src2[] = { 1.f, 3.f, 6.f, 10.f, 15.f, 21.f, 28.f, 36.f };
+    bfloat16x8_t s1 = vld1q_as_bf16(src1), s2 = vld1q_as_bf16(src2);
+    float32x4_t d = vbfdotq_f32(vdupq_n_f32(0.f), s1, s2);
+    vprintreg("(s1[0]*s2[0] + s1[1]*s2[1], ... s1[6]*s2[6] + s1[7]*s2[7])", d);
+}
+/*#if defined __clang__
+#pragma clang attribute pop
+#elif defined GCC
+#pragma GCC pop_options
+#endif*/
+#else
+#error "BF16 is not supported"
+#endif
+
+int main()
+{
+    test();
+    return 0;
+}