In a previous job, we had a cross compiler that cross/decompiled a static x86 Linux binary to Java bytecode (with syscalls emulated in Java). Testing this on an ARM processor the Java version of a scientific benchmark we were using was significantly faster (1.6X) than the best gcc could do with the original C. This wasn't anything fancy our cross-compiler had done, but the JVM itself. This isn't a comparison to x86 hardware, just an indication of the effort put into the ARM based JVM.