Why exceptions for error handling is so important

[Walter Bright via Digitalmars-d]

On 1/12/2015 4:40 PM, deadalnix wrote:
> These are trash register. Meaning the callee can put whatever in them. The
> caller must consider them trashed after the call.
>
> So no, it do NOT increase register pressure.

1. the register must be assigned a value - that has a cost
2. functions often get inlined
3. it prevents EDX from being used by the return value, when the return value is 
larger than a single register size
4. static functions may not need to follow the C ABI register convention, and 
can be so optimized