Details Title: Assembly x86 Description: flash cards about things related to Assembly Language Total Flash Cards: 17 Created: 05/24/2007 14:15:29		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Computer Science Flashcards
Cards in this set: Term Difference between overflow and carry? Definition overflow - signed numbers carry - unsigned numbers Term What is a register and why do we need them? Definition A register stores memory and it is the only place to put memory in the CPU. Term What does a compiler generate? Definition an object file Term What is a stack frame? Definition a chunk of the stack to store all items and memory of a function. every process has a stack Term Give two examples of addressing modes Definition register direct, immediate Term How does an assembler work? Definition Reads in a line of code, makes a table out of it and turns it into object code. Also has two passes. Term What assembly code do we use to declare an integer in the data segment with initial value 2? Definition myInt: .long 2 Term What is memory direct addressing good for? Definition Good for quickly restoring values. Term What size is the machine language code for movl %esp, %ebp? Definition 2 bytes Term Where is the return value for any called function? Definition %eax Term Where are the parameters for the read function call, and what is the order of those parameters (in general)? Definition in the stack: pushl $#chars pushl $buffer pushl $0 call read addl $12, %esp Term Why would you use scanf/printf instead of read/write? Definition Runtime is shorter and you don't need to specify the # of chars Term What does the register indirect addressing mode do? Definition Allows the register to act as a pointer Term How do we specify register indirect for %eax? Definition Put parentheses around the register: (%eax) Term What instruction would you use to turn off the least significant bit in register %al? Definition andb $bx11111110, %al Term What is the ZF? Definition zero flag Used to change the zero bit Term Difference between pushl $72 and pushl 72? Definition pushl 72 = pushes contents of 72 onto stack pushl $72 = pushes the actual number 72 onto the stack