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28 lines
498 B
C
28 lines
498 B
C
module std::math::nolibc @if(env::NO_LIBC);
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fn double _scalbn(double x, int n) @weak @extern("scalbn") @nostrip
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{
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switch
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{
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case n > 1023:
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x *= 0x1p1023;
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n -= 1023;
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if (n > 1023)
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{
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x *= 0x1p1023;
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n -= 1023;
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if (n > 1023) n = 1023;
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}
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case n < -1022:
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x *= 0x1p-1022 * 0x1p53;
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n += 1022 - 53;
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if (n < -1022)
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{
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x *= 0x1p-1022 * 0x1p53;
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n += 1022 - 53;
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if (n < -1022) n = -1022;
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}
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}
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return x * bitcast(((ulong)(0x3ff + n)) << 52, double);
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}
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