What would the "real CPU from MIPS" be, and how much difference would that make...? Loongson is a licensed design.
As for compilers, neither ARM's nor Intel's compiler were used for the other CPUs, so I think that's a fair comparison. ...and I thought one of the reasons to choose a very simple RISC like MIPS was that its simplicity made compiler optimisations easier?
AFAIK Loongson just licensed the patent necessary to implement the MIPS ISA but the implementation was done by chineese academia without any intervention from MIPS. You cannont judge the quality of MIPS processors in general by looking only at one chineese clone...
As for compilers, neither ARM's nor Intel's compiler were used for the other CPUs, so I think that's a fair comparison. ...and I thought one of the reasons to choose a very simple RISC like MIPS was that its simplicity made compiler optimisations easier?