38 lines
571 B
C
38 lines
571 B
C
/* bitops-__ffs.h COPYRIGHT FUJITSU LIMITED 2014 */
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#ifndef INCLUDE_BITOPS___FFS_H
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#define INCLUDE_BITOPS___FFS_H
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static inline unsigned long __ffs(unsigned long word)
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{
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int num = 0;
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if (BITS_PER_LONG == 64) {
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if ((word & 0xffffffff) == 0) {
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num += 32;
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word >>= 32;
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}
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}
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if ((word & 0xffff) == 0) {
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num += 16;
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word >>= 16;
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}
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if ((word & 0xff) == 0) {
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num += 8;
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word >>= 8;
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}
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if ((word & 0xf) == 0) {
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num += 4;
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word >>= 4;
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}
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if ((word & 0x3) == 0) {
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num += 2;
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word >>= 2;
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}
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if ((word & 0x1) == 0)
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num += 1;
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return num;
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}
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#endif
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