40 lines
768 B
C
40 lines
768 B
C
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#include <stdint.h> // uint32_t
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#include "config.h"
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/* Test that the byte order detected at runtime matches the one detected at
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* compile time.
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*/
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/* Return:
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*
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* 0 if the runtime and compile time byte orders match
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*
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* 1 if the runtime and compile time byte orders do not match
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*
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* 2 if the BYTE_ORDER macro has a value other than BIG_ENDIAN or
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* LITTLE_ENDIAN
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*
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* 3 if not all of the byte order macros are defined
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*/
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int
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main ()
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{
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#if !defined(BYTE_ORDER) || !defined(BIG_ENDIAN) || !defined(LITTLE_ENDIAN)
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return 3;
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#endif
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union {
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uint32_t i;
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unsigned char a[4];
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} u = {1};
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#if BYTE_ORDER == LITTLE_ENDIAN
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return u.a[0] == 1 ? 0 : 1;
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#elif BYTE_ORDER == BIG_ENDIAN
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return u.a[3] == 1 ? 0 : 1;
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#else
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return 2;
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#endif
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}
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