On 31 July 2005 08:10, Bulat Ziganshin wrote:
can you please say about value of using C-- in GHC? will this reduce compile time, increase speed of compiled programs, improve portability or make some other effect? would the C-- compile path replace asm or C path?
It should reduce compile time compared to compiling via C, though I suspect it will still be slower than using GHC's built-in native code generator. It should improve the speed of compiled programs, because C-- will be using its own, efficient, calling convention. For example, this will mean that some arguments can be passed in registers on x86, which we can't do currently because of a combination of the lack of registers and limitations in what we can convince gcc to do. It should improve portability, because there is less work in GHC required to compile via C-- on a new platform: no mangler to modify, for example. Eventually, we hope the registerised via-C path would become redundant. The unregisterised path is still useful for bootstrapping, given that more platforms have a C compiler than a C-- compiler (if C-- were to become ubiquitous, the unregisterised path would become irrelevant too). Cheers, Simon