”@
c++ Programming Glossary: unalignedDo I really have to worry about alignment when using placement new operator? http://stackoverflow.com/questions/11781724/do-i-really-have-to-worry-about-alignment-when-using-placement-new-operator drawbacks in my case would be performance penalty I mean unaligned access cost more than aligned c g powerpc placement new share.. aligned and of the requested size. So if you pass unaligned storage to a placement new expression you're violating the assumption..
http://stackoverflow.com/questions/12183780/about-struct-padding of safety and performance. On certain architectures an unaligned read causes a crash. So the compiler pads the struct so that..
Why one should not hide a structure implementation that way? http://stackoverflow.com/questions/17619015/why-one-should-not-hide-a-structure-implementation-that-way CPUs will silently corrupt read write operations to unaligned memory address some others will generate a fault. The latter.. The latter is better. bad for performance if supported unaligned access load store are still known to be poorly handled you're..
http://stackoverflow.com/questions/3874615/placement-new-issue reason a naive attempt to create an int array in such an unaligned buffer will fail. The alignment requirements on some platform..
C++ performance challenge: integer to std::string conversion http://stackoverflow.com/questions/4351371/c-performance-challenge-integer-to-stdstring-conversion val 10 return s This will blow up on systems that disallow unaligned memory accesses in which case the first unaligned assignment.. disallow unaligned memory accesses in which case the first unaligned assignment via short would cause a segfault but should work..
Atomicity in C++ : Myth or Reality http://stackoverflow.com/questions/5002046/atomicity-in-c-myth-or-reality of atomically for newer processors like Core2. Not all unaligned operations will be atomic. Other intel manual recommends this..
http://stackoverflow.com/questions/5216071/sse-and-c-containers For gcc I don't know. Under C 0x for new point to return unaligned storage is a serious non compliance. basic.stc.dynamic.allocation..
C++: optimizing member variable order? http://stackoverflow.com/questions/892767/c-optimizing-member-variable-order is platform dependent on ARM it absolutely has to be since unaligned access throws a hardware exception. On x86 you can access ints.. throws a hardware exception. On x86 you can access ints unaligned but it's generally slower and IIRC non atomic. So compilers.. j same short s usually 2 bytes could be 2 aligned or unaligned I don't know char c 4 array 4 chars 4 bytes big but never needs..
|