ios build successfully.

src/operators/math/gemm.cpp

@@ -3379,7 +3379,7 @@ void Gemm::SgemmWithBn_omp(int m, int n, int k, float alpha, const float *A,
     // 对 B 分块
     NC = L1 / (KC * sizeof(float));
     if (NC == 0) {
-      NC == NR;
+      NC = NR;
     } else {
       int nblock_num = (n + NC - 1) / NC;
       NC = (n + nblock_num - 1) / nblock_num;

src/operators/math/gemm.h

@@ -22,6 +22,7 @@ limitations under the License. */
 #define C(i, j) C[(i)*ldc + (j)]
 
 #if __aarch64__
+#define MR_INT8 4
 #define MR 6
 #define NR 16
 #else