SuperWordLoopUnrollAnalysis and loop unrolling

[Andrew Haley]

On 14/04/17 10:21, Yang Zhang wrote:
> My test result is just opposite with your description. Could you
> provide your test case?

    // @Benchmark
    public int[] sameArrayClass(BenchmarkState state) {
        for (int i = 0; i < INITSIZE; i++) {
            state.b[0] = state.b[1];
            state.b[1] = state.b[2];
            state.b[2] = state.b[3];
            state.b[3] = state.b[0];

            state.b[0] = state.b[1];
            state.b[1] = state.b[2];
            state.b[2] = state.b[3];
            state.b[3] = state.b[0];

            state.b[0] = state.b[1];
            state.b[1] = state.b[2];
            state.b[2] = state.b[3];
            state.b[3] = state.b[0];

            state.b[0] = state.b[1];
            state.b[1] = state.b[2];
            state.b[2] = state.b[3];
            state.b[3] = state.b[0];
        }
        return state.b;
    }

This is not vectorizable, but SuperWordLoopUnrollAnalysis=true disables
the unrolling which would make it faster.

Andrew.