33 lines
987 B
C
33 lines
987 B
C
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#ifndef HAKMEM_TINY_PTR_CONVERT_BOX_H
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#define HAKMEM_TINY_PTR_CONVERT_BOX_H
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#include <stddef.h>
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// Purpose: Zero-overhead inline conversions between BASE and USER pointers
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// Contract: Header is stored at offset -1 from USER pointer
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//
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// Example:
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// - Allocation: base → user (user = base + 1)
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// - Deallocation: user → base (base = user - 1)
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//
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// Offset definition (centralized for future extension)
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#define TINY_HEADER_OFFSET 1
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// Direct inline macros (zero cost, lvalue compatible in some contexts)
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#define tiny_base_to_user_inline(base) \
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((void*)((char*)(base) + TINY_HEADER_OFFSET))
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#define tiny_user_to_base_inline(user) \
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((void*)((char*)(user) - TINY_HEADER_OFFSET))
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// Verbose variants (for clarity in critical paths)
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static inline void* tiny_base_to_user(void* base) {
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return tiny_base_to_user_inline(base);
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}
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static inline void* tiny_user_to_base(void* user) {
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return tiny_user_to_base_inline(user);
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}
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#endif // HAKMEM_TINY_PTR_CONVERT_BOX_H
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