Allasso

Hello, I have observed that when generating assembly code from simple C programs using GCC, the stack is initialized as follows: [CODE]pushl %ebp movl %esp, %ebp andl $-16, %esp [/CODE] my question concerns the last instruction where -16 is anded with the stack pointer. Am I correct in assuming that …

Hello, I am learning ia-32 assembly. I have observed that when creating an object file using gcc from the simple c program: [CODE]main () { char buf[256]; write(1, buf, 256); } [/CODE] it generates the following instruction for the write: (using the data on top of the stack for the …

Hello, Is there a reference anywhere that I can find out the number of cycles each instruction takes for ia-32 processors? I do not find this information in the docs, neither has much googling come up with anything. Thanks, Allasso

Hello, I have broadened my question posted yesterday. I would like to know how to approach writing system functions such as open, write, read, etc, without using syscall. I am using GCC. eg, I can call these functions using c, yet I understand that the compiler uses functions from a …

Hello, I have been trying to learn assembly code for PPC on a Mac OS 10.5. I have wanted to see how, when compiling a c program, GCC uses libraries on the Mac to insert instructions to perform functions such as malloc(), write() and printf() in a way that is …

Hello, I would like to use a simple "if then" test to check if an argument to a command begins with "http://" as follows: if [[ $2 == [url]http://*[/url] ]]; then command fi but the wildcard just seems to be ignored, ie., it will only execute the command if the …