42 lines
852 B
C
42 lines
852 B
C
//---
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//
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// gint libc module: math
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//
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// Provides mathematical functions as well as a few useful extensions.
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//
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//---
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#ifndef _MATH_H
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#define _MATH_H
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#include <stdint.h>
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//---
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// Function extensions
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//---
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/*
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qdiv()
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Quickly divides by predefined integers using a 64-bit multiplication
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technique. These functions should be ~10 times faster than dividing
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using opeator "/".
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*/
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typedef struct qdiv_t
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{
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uint32_t q; /* Quotient */
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uint32_t r; /* Remainer */
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} __attribute__((packed, aligned(4))) qdiv_t;
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qdiv_t qdiv(uint32_t n, uint32_t divider, uint32_t reciprocal);
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/* Predefined magic numbers */
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#define qdiv_3(n) qdiv(n, 3, 0x55555556)
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#define qdiv_5(n) qdiv(n, 5, 0x33333334)
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#define qdiv_10(n) qdiv(n, 10, 0x1999999a)
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#define qdiv_100(n) qdiv(n, 100, 0x028f5c29)
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#define qdiv_1000(n) qdiv(n, 1000, 0x00418938)
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#endif // _MATH_H
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