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Understanding Memory Alignment, Cache Lines & Structure Padding in x86_64

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4y ago · Mar 6, 2022 11:07 AM

CPUs fetch memory in 64-byte cache lines. Struct member reordering can dramatically reduce cache misses and struct sizeof padding.

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4y ago · Mar 6, 2022 1:17 PM

Alignas(64) on hot variables prevents false sharing between CPU cores in multi-threaded loops.

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4y ago · Mar 8, 2022 3:17 PM

Compilers insert implicit padding to align 64-bit pointers to 8-byte boundaries. Reordering largest to smallest types shrinks structures.

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