bc2a444828
A signed integer cannot be shifted in a way that will flip the sign bit; make such arguments unsigned to be safe Change-Id: Iafc060f98f899ae3ffb876ba22fdd6183fbb6e57
37 lines
473 B
C
37 lines
473 B
C
/* bitops-fls.h COPYRIGHT FUJITSU LIMITED 2015-2016 */
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#ifndef INCLUDE_BITOPS_FLS_H
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#define INCLUDE_BITOPS_FLS_H
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static inline int fls(unsigned int x)
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{
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int r = 32;
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if (!x) {
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return 0;
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}
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if (!(x & 0xffff0000u)) {
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x <<= 16;
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r -= 16;
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}
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if (!(x & 0xff000000u)) {
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x <<= 8;
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r -= 8;
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}
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if (!(x & 0xf0000000u)) {
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x <<= 4;
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r -= 4;
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}
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if (!(x & 0xc0000000u)) {
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x <<= 2;
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r -= 2;
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}
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if (!(x & 0x80000000u)) {
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x <<= 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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#endif
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