Many standard C functions are treated as “magic” by compilers. Malloc is treated as if it has no side effects (which of course it does, it changes allocator sta

Many standard C functions are treated as “magic” by compilers. Malloc is treated as if it has no side effects (which of course it does, it changes allocator state) so the optimiser can elide allocations. If not you wouldn’t be able to elide the call because malloc looks like it has side effects, which it does but not ones we care about observing.