Passing arrays to NASM DLL, pointer value gets reset to zero
问题 I am passing three arrays of doubles from Python (3.6.2) into a DLL written in 64-bit NASM (Windows) using CTypes. The pointers to the arrays are in rcx, rdx, r8 and r9. On entry, I extract the pointers into three separate arrays, called a_in_data, b_in_data, and c_in_data. The elements of those arrays are (1) pointer (2) data type and (3) length. In the area preceded by "Test #1" in the code below we check the value at b_in_data[0] and we get a valid pointer (just remove the comment symbols