On 9 August 2015 at 07:31, Walter Bright via Digitalmars-d < [email protected]> wrote:
> On 8/8/2015 7:40 PM, Manu via Digitalmars-d wrote: > >> 1. DMD has unsatisfactory codegen for anything other than debug builds. >> > > Do you mean the codegen is slower? But consider that the bottleneck in > most programs is a small section of code. Taking a good look at the > generated code for that and comparing with another compiler can often hint > at an easy improvement to dmd that can address that bottleneck. > > But waiting for someone else to discover the same thing on some other > piece of code means you'll be waiting a long time. > > Sometimes just using the wrong CPU can have adverse effects: https://issues.dlang.org/show_bug.cgi?id=5100 > > 2. DMD generates x87 code, and uses real everywhere. >> > > Less so now than it used to. For float and double, it uses SIMD. > > We can't be >> generating new x87+real instructions in 2015. It's deprecated >> hardware! >> > > x87 works on every x86 CPU, and I doubt it will ever go away, deprecated > or not. Why was it a problem for you? > > I know that at least for the benefit of std.math, we should allow any precision without expensive casting to and from real, which has been found to be a performance problem on various benchmarks (GDC, LDC, DMD, doesn't matter). Iain.
