BUS 218 Exam 1 Questions With Verified Answers

relationship between "machine code" and "assembly language" - Answer they have 1 to 1 ratio layout of rax register - Answer rax - 64 bits (entire register) or 8 bytes eax - lower 32 bits or 4 bytes ax - lower 16 bits or 2 bytes ax = ah:al al and ah - 8 bits or 1 byte al - lowest 8 bits bits in al - Answer 8 bits in rcx - Answer 64 bits in bx - Answer 16 bits in edx - Answer 32 what does rip register refer to - Answer instruction pointer register what does the rsp register refer to - Answer stack pointer register how many bits does one hex digit require - Answer 4 bits range of byte - Answer signed: -(2^7) to (2^7)- 1 unsigned: 0 to (2^8) - 1 range of word - Answer signed: -(2^15) to (2^15)-1 unsigned: 0 to (2^16)-1 range of double word - Answer signed: -(2^31) to (2^31)-1 unsigned: 0 to (2^32)-1 on the intel 80x86 base architecture, how many bytes can be stored at each address - Answer 1 byte tell what each instruction does: (1) mov rax, qword [var] (2) mov rax, var - Answer (1) copies value of var in rax (2) address of var copies into rax can a constant be changed during program execution - Answer no what register refers to the current top of the stack - Answer rsp when a macro is invoked, how many times is the code placed into the code segment - Answer it is placed into the code segment the number of times it is invoked what happens as a result of a push rax instruction - Answer (1) decrements rsp by 8 (2) copies rax value to rsp (top of stack) how many bytes of data does the pop rax instruction remove from the stack - Answer 8 bytes when arguments are passed using values, it's referred to as - Answer pass by value when arguments are passes using addresses, it's referred to as - Answer pass by reference according to the standard calling convention, what's the purpose of the initial push's and final pop's within most functions - Answer to preserve and restore saved registers what is the purpose of the add rsp , <immediate> after the call statement - Answer to clear out any arguments in the stack if three arguments are passed on the stack , what is the value for the immediate - Answer 24 (8 * 3) if a function is called 73 times, how many copies of the function code are placed into memory - Answer only one existence of the function code exists Draw the Von Neumann architecture - Answer What architecture component connects the memory to the CPU? - Answer Bus or interconnection where are programs stored when the computer is turned off - Answer secondary storage where must programs be located when they are executing - Answer primary storage or main memory (ram) how does cache memory help overall performance - Answer Keeps a copy of the data closer to the CPU, eliminating the extra time required to access the RAM via the Bus. How many bytes does a C++ integer declared with the declaration int use? - Answer 4 bytes most significant byte - Answer left most byte least significant byte - Answer rightmost byte bits in r11 - Answer 64 bits in r8b - Answer 8 bits in sil - Answer 8 bits in r14w - Answer 16 which register points to the next instruction to be executed - Answer rip register what is the name of the assembler being used in the class - Answer yasm name of section where initialized data is declared - Answer data name of section where uninitialized data is declared - Answer bss name of section where code is placed - Answer text