DMD buggy optimizing

[Dave]

Walter Bright wrote:
> 
> The D optimizer is the same one as the DMC++ one that has been around 
> for 20 years and several hundred thousand users. I run across an actual 
> optimizer bug maybe once a year now. D benefits a lot from its maturity.
> 

I think the DMD optimizer is great for integer stuff, especially 
considering the great performance of the compiler itself. My only 
complaints are that for some/many floating point operations, the FP 
registers are not used as they could be. This is frustrating especially 
since D does not have to live by any of the C/++ "excess precision" 
rules (so it should make as much use of the 80 bit registers as possible).

3 reasons I care: I'd like to flip the -O switch and know I'm getting 
great code generated whether or not it's int or FP. Also, I don't want 
to spend a lot of time tweaking things. The other reason is I don't want 
DMD (and by extension D) to be unreasonably dismissed because of some 
perceived issue in this area.