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594ef81326
Change-Id: Ifb41050e729a0ce314e4d4918e46f82bc7e16bed Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com> Reviewed-on: http://review.coreboot.org/4684 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
45 lines
744 B
C
45 lines
744 B
C
#undef DEBUG_LOG2
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#ifdef DEBUG_LOG2
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#include <console/console.h>
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#endif
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#include <lib.h>
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/* Assume 8 bits per byte */
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#define CHAR_BIT 8
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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 = 1ULL << (sizeof(x)* CHAR_BIT - 1ULL);
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unsigned long pow = sizeof(x) * CHAR_BIT - 1ULL;
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if (! x) {
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#ifdef DEBUG_LOG2
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printk(BIOS_WARNING, "%s called with invalid parameter of 0\n",
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__func__);
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#endif
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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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unsigned long log2_ceil(unsigned long x)
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{
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unsigned long pow;
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if (! x)
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return -1;
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pow = log2(x);
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if (x > (1ULL << pow))
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pow++;
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return pow;
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}
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