Perhaps historically ICC was buggy, but I don't think it's true anymore. I often test highly optimized C code with GCC, Clang, and ICC, and anecdotally I'd say that the likelihood of hitting a compiler bug when compiling for a current Intel processor is about the same for each.
For me, crashing bugs and true miscompilation are rare with all three, but come up occasionally. Performance differences are usually within +/- 20% on microbenchmarks, with each having about equal chances of being the fastest or slowest.
Perhaps historically ICC was buggy, but I don't think it's true anymore. I often test highly optimized C code with GCC, Clang, and ICC, and anecdotally I'd say that the likelihood of hitting a compiler bug when compiling for a current Intel processor is about the same for each.
For me, crashing bugs and true miscompilation are rare with all three, but come up occasionally. Performance differences are usually within +/- 20% on microbenchmarks, with each having about equal chances of being the fastest or slowest.