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// SPDX-License-Identifier: MIT
// Copyright (c) 2015-2021 Zig Contributors
// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
// The MIT license requires this copyright notice to be included in all copies
// and substantial portions of the software.
const builtin = @import("builtin");
const is_test = builtin.is_test;
const std = @import("std");
const maxInt = std.math.maxInt;
const significandBits = 112;
const exponentBias = 16383;
const implicitBit = (@as(u128, 1) << significandBits);
pub fn __floatditf(arg: i64) callconv(.C) f128 {
@setRuntimeSafety(is_test);
if (arg == 0)
return 0.0;
// All other cases begin by extracting the sign and absolute value of a
var sign: u128 = 0;
var aAbs = @bitCast(u64, arg);
if (arg < 0) {
sign = 1 << 127;
aAbs = ~@bitCast(u64, arg) + 1;
}
// Exponent of (fp_t)a is the width of abs(a).
const exponent = 63 - @clz(u64, aAbs);
var result: u128 = undefined;
// Shift a into the significand field, rounding if it is a right-shift
const shift = significandBits - exponent;
result = @as(u128, aAbs) << shift ^ implicitBit;
result += (@as(u128, exponent) + exponentBias) << significandBits;
return @bitCast(f128, result | sign);
}
test "import floatditf" {
_ = @import("floatditf_test.zig");
}
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