43 lines
533 B
C
43 lines
533 B
C
#ifndef FIO_FFZ_H
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#define FIO_FFZ_H
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static inline int __ffs(unsigned long word)
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{
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int r = 0;
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#if BITS_PER_LONG == 64
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if ((word & 0xffffffff) == 0) {
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r += 32;
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word >>= 32;
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}
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#endif
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if (!(word & 0xffff)) {
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word >>= 16;
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r += 16;
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}
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if (!(word & 0xff)) {
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word >>= 8;
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r += 8;
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}
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if (!(word & 0xf)) {
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word >>= 4;
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r += 4;
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}
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if (!(word & 3)) {
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word >>= 2;
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r += 2;
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}
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if (!(word & 1)) {
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word >>= 1;
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r += 1;
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}
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return r;
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}
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static inline int ffz(unsigned long bitmask)
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{
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return __ffs(~bitmask);
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}
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#endif
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