Seems like you can have the cake and eat it too, by manually parallelizing the code to something like this: double A4 = A+A+A+A; double Z = 3A+B; d

Seems like you can have the cake and eat it too, by manually parallelizing the code to something like this: double A4 = A+A+A+A; double Z = 3A+B; double Y1 = C; double Y2 = A+B+C; int i; // ... setup unroll when LEN is odd... for(i=0; i<LEN; i++) { data[i] = Y1; data[++i] = Y2; Y1 += Z; Y2 += Z; Z += A4; } Probably not entirely functional as written, but you get the idea: unroll the loop so that the data dependent paths can each be done in parallel. For the machine being considered, a 4 step unroll should achieve maximum performance, but of course, you get all the fun things that come with hard-coding the architecture in your software.