22 lines
551 B
C
22 lines
551 B
C
#define _GNU_SOURCE
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#include "libc/math/libm.h"
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float exp10f(float x)
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{
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static const float p10[] = {
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1e-7f, 1e-6f, 1e-5f, 1e-4f, 1e-3f, 1e-2f, 1e-1f,
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1, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7
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};
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float n, y = modff(x, &n);
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union {float f; uint32_t i;} u = {n};
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/* fabsf(n) < 8 without raising invalid on nan */
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if ((u.i>>23 & 0xff) < 0x7f+3) {
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if (!y) return p10[(int)n+7];
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y = exp2f(3.32192809488736234787031942948939f * y);
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return y * p10[(int)n+7];
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}
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return exp2(3.32192809488736234787031942948939 * x);
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}
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weak_alias(exp10f, pow10f);
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