zig/lib/std/special/compiler_rt/floatundidf.zig

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Zig

const builtin = @import("builtin");
const std = @import("std");
const twop52: f64 = 0x1.0p52;
const twop84: f64 = 0x1.0p84;
const twop84_plus_twop52: f64 = 0x1.00000001p84;
pub fn __floatundidf(a: u64) callconv(.C) f64 {
@setRuntimeSafety(builtin.is_test);
if (a == 0) return 0;
var high = @bitCast(u64, twop84);
var low = @bitCast(u64, twop52);
high |= a >> 32;
low |= a & 0xFFFFFFFF;
return (@bitCast(f64, high) - twop84_plus_twop52) + @bitCast(f64, low);
}
pub fn __aeabi_ul2d(arg: u64) callconv(.AAPCS) f64 {
@setRuntimeSafety(false);
return @call(.{ .modifier = .always_inline }, __floatundidf, .{arg});
}
test "import floatundidf" {
_ = @import("floatundidf_test.zig");
}