x86

问题 I am trying to follow this tutorial for creating a binary file, but the linker appears to be appending additional instructions at the end of the assembly. I assume this is the OS's tear-down process. The tutorial attempts to compile a bare bones 32-bit C program on Linux: int main() { } using these commands: gcc -c test.c ld -o test -Ttext 0x0 -e main test.o objcopy -R .note -R .comment -S -O binary test test.bin ndisasm -b 32 test.bin I am running 64-bit Linux, and hence modified the

问题 I am trying to follow this tutorial for creating a binary file, but the linker appears to be appending additional instructions at the end of the assembly. I assume this is the OS's tear-down process. The tutorial attempts to compile a bare bones 32-bit C program on Linux: int main() { } using these commands: gcc -c test.c ld -o test -Ttext 0x0 -e main test.o objcopy -R .note -R .comment -S -O binary test test.bin ndisasm -b 32 test.bin I am running 64-bit Linux, and hence modified the

问题 I am trying to follow this tutorial for creating a binary file, but the linker appears to be appending additional instructions at the end of the assembly. I assume this is the OS's tear-down process. The tutorial attempts to compile a bare bones 32-bit C program on Linux: int main() { } using these commands: gcc -c test.c ld -o test -Ttext 0x0 -e main test.o objcopy -R .note -R .comment -S -O binary test test.bin ndisasm -b 32 test.bin I am running 64-bit Linux, and hence modified the

问题 If I have 2 denormal floating point numbers with different bit patterns and compare them for equality, can the result be affected by the Denormals-Are-Zero flag, the Flush-to-Zero flag, or other flags on commonly used processors? Or do these flags only affect computation and not equality checks? 回答1: DAZ (Denormals Are Zero) affects reading input, so DAZ affects compares . All denormals are literally treated as -0.0 or +0.0 , according to their sign. FTZ (Flush To Zero) affects only writing

问题 If I have 2 denormal floating point numbers with different bit patterns and compare them for equality, can the result be affected by the Denormals-Are-Zero flag, the Flush-to-Zero flag, or other flags on commonly used processors? Or do these flags only affect computation and not equality checks? 回答1: DAZ (Denormals Are Zero) affects reading input, so DAZ affects compares . All denormals are literally treated as -0.0 or +0.0 , according to their sign. FTZ (Flush To Zero) affects only writing

问题 I am trying to read and write values from registers in python using the LLDB API. For the General Purpose Registers, I have been using the frame.register['register name'].value to read and write register values, which works successfully for me. However, as I approach the Floating Point Registers, I found that this could not be done anymore, as some of the registers, such as the XMM registers do not have a value attribute e.g frame.register['xmm0'].value would return None . I have looked into

问题 I'm very new to Assembly and the code below is supposed to swap two integers via two different functions: first using swap_c and then using swap_asm . However, I doubt, whether I need to push (I mean save) each value of registers before assembly code and pop them later (just before returning to main ). In other words, will the CPU get mad at me if I return different register content (not the crucial ones like ebp or esp ; but, just eax , ebx , ecx & edx ) after running swap_asm function? Is

问题 I'm very new to Assembly and the code below is supposed to swap two integers via two different functions: first using swap_c and then using swap_asm . However, I doubt, whether I need to push (I mean save) each value of registers before assembly code and pop them later (just before returning to main ). In other words, will the CPU get mad at me if I return different register content (not the crucial ones like ebp or esp ; but, just eax , ebx , ecx & edx ) after running swap_asm function? Is

问题 I'm very new to Assembly and the code below is supposed to swap two integers via two different functions: first using swap_c and then using swap_asm . However, I doubt, whether I need to push (I mean save) each value of registers before assembly code and pop them later (just before returning to main ). In other words, will the CPU get mad at me if I return different register content (not the crucial ones like ebp or esp ; but, just eax , ebx , ecx & edx ) after running swap_asm function? Is

问题 C++11 specifies six memory orderings: typedef enum memory_order { memory_order_relaxed, memory_order_consume, memory_order_acquire, memory_order_release, memory_order_acq_rel, memory_order_seq_cst } memory_order; https://en.cppreference.com/w/cpp/atomic/memory_order where the default is seq_cst. Performance gains can be found by relaxing the memory ordering of operations. However, this depends on what protections the architecture provides. For example, Intel x86 is a strong memory model and