Honestly, GCC was a pretty good optimizing compiler even on RISC architectures. The one exception was on SPARC, because the optimizer didn't take advantage of t

Honestly, GCC was a pretty good optimizing compiler even on RISC architectures. The one exception was on SPARC, because the optimizer didn't take advantage of the "register windows" feature, which arguably is the most un-RISCy aspect of the SPARC architecture. RISC vendors often shipped carefully optimized floating point libraries, which would result in floating-point optimized code from their compilers outperforming gcc, but for fixed point performance GCC was often competitive and even superlative to the offerings from RISC vendors. If you look through the history of SPEC benchmarks, you'll see that for SPECint, GCC was as much the compiler of choice for RISC vendors as it was for CISC vendors.