atomicOp wrong results for double or infinite loop

[fyfrey]

Hi everyone,
I just stumbled upon a weird bug with atomicOp!"+=" on double variables. float is not affected. System: Arch Linux x64.
The following code works fine with dmd but fails with ldc (1.13 and 1.14 beta, both debug and optimized release):

import core.atomic;
import std.stdio;
void main()
{
    shared double data = 0.1;
    data.atomicOp!"+="(0.1);
    writeln(data); // prints 0.2 with dmd, 0.6 with ldc
}

If you further change one line to data.atomicOp!"+="(1.0); computation is stuck in an infinite loop.

Edit: When only using values that can be exactly represented (like 1.0 or 0.5) in both initialization and the atomicOp, computation is both correct and fast.

[kinke]

Wow, thx for reporting.