19 lines
427 B
C
19 lines
427 B
C
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#include <console/console.h>
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unsigned long log2(unsigned long x)
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{
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// assume 8 bits per byte.
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unsigned long i = 1 << (sizeof(x)*8 - 1);
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unsigned long pow = sizeof(x) * 8 - 1;
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if (! x) {
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printk_warning("%s called with invalid parameter of 0\n",
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__FUNCTION__);
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return -1;
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}
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for(; i > x; i >>= 1, pow--)
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;
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return pow;
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}
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