I am studying the issue of alignment check. But I don't know whether the processor is checking on effective addresses, linear addresses or physical addresses, or all checks. For example, the effect...

Is there any standardized function in GCC or glibc to allocate memory block at aligned pointer? Like _align_malloc() in MSVC?

Do the memory alignment issues with Eigen listed in the documentation still apply with C++11? It seems that C++11 can already take care of properly aligning objects on the stack and on the heap, wi...

Edit: Thanks for everyone's answer and replies. Language Lawyer's answer is technically the correct one so that's accepted, but Human-Compiler's answer is the only one that meets the criteria (get...

I've just stumbled upon the std::alignment_of type trait, and its soon-to-be friend std::alignment_of_v. They seem to have been specifically designed to be equivalent to a plain call to alignof, an...

I am compiling this code for a Cortex M7 using GCC: // copy manually void write_test_plain(uint8_t * ptr, uint32_t value) { *ptr++ = (u8)(value); *ptr++ = (u8)(value >> 8); *ptr++ = (u8)(...

I write an image processing app that needs to do multiple things and it has to do them as much real-time as possible. Acquisition of the data and their processing runs in separate processes (mainl...

I want to emulate the system with prohibited unaligned memory accesses on the x86/x86_64. Is there some debugging tool or special mode to do this? I want to run many (CPU-intensive) tests on the s...

Is there a linux equivalent of _aligned_realloc? I want to use realloc so I don't have to memcpy the data every time I resize it. Am I stuck with mmap? I only used mmap once is there a recommended ...

I know why GCC doesn't re-order members of a structure by default, but I seldom write code that relies on the order of the structure, so is there some way I can flag my structures to be automaticly...

These structs, align1 and align2, contain the same data, but align1 has more padding due to the nested layout. How can I get the memory saving alignment of align2 while also using a nested struct l...

Many C/C++ compilers (including gcc and clang) have a feature called packed structures. It comes in handy for a number of reasons, but it has to be used with caution. One potential pitfall is that ...

Overview When browsing operator new, operator new[] - cppreference.com, it seems we have a number of options for allocating arrays of objects with specific alignment requirements. However, it is no...

I tried to create a smart pointer that has only one pointer to a block of memory, which starts with a reference counter (control block), and a value stored immediately after it. And after reading s...

I'm not used to post any question on the internet so please tell me if I'm doing something wrong. In short How to correctly prevent false sharing on a 64bits architecture with a CPU cacheline size...

Aim: To understand the motivation why C++17 introduced std::aligned_alloc for dynamic memory management. Problem: For the memory allocation in C++, using std::malloc is virtually always discouraged...

I was learning about structure padding, and read that the reason behind structure padding is that if the members of the struct are not aligned, the processor won't be able to read/write them in onl...

I just learnt about alignof and alignas C++ keywords but I can't think about any practical case where a developer would want to use these keywords. Does somebody know any practical use case for the...

Because of a lack of PUSH and POP instructions in ARM64, I'm having a problem with understanding how SP work in ARM64. If I were to PUSH/POP, does the SP decrement/increment by 4, 8 or 16 bytes? I'...

Suppose I have the following simple class: struct employee{ std::string name; short salary; std::size_t age; employee(std::string name, short salary, std::size_t age) : name{name}, salary{sal...

Suppose that I am in a 64-bit machine compiling a C program with gcc. I'm assuming that sizeof(int) is 8 bytes, and sizeof(char) is 1 byte. Because of memory alignment, the following struct: stru...

I ran the following program on my computer (64-bit Intel running Linux). #include <stdio.h> void test(int argc, char **argv) { printf("[test] Argc Pointer: %p\n", &argc); printf("[tes...

I have the following data segment .data a: .byte 0x11 .align 1 b: .word 0x22334455 Assuming that address "a" is 0x10010000, then the expected address for the word at b is 0x10010002, but MARS s...

i'm new to C++ so i'm trying some leetcode problems. i'm currently attempting the min stack problem. i think i've solved it correctly, except i get the following runtime error from leetcode: Line ...

I wrote a simple example: #include <iostream> int main() { void* byte1 = ::operator new(1); void* byte2 = ::operator new(1); void* byte3 = malloc(1); std::cout << "byte1: " <&l...