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It is sometimes necessary in low-level kernel or graphics code to access memory at a specific location, requiring a literal integer to pointer conversion such as the following:
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These conversions are machine dependent , and should only be coded when absolutely necessary.
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In this non-compliant code example, the pointer ptr is converted to an integer value. Both a pointer and an int are assumed to be 32 bits. The high-order nine bits of the number are used to hold a flag value, and the result is converted back into a pointer.
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