nkurz

gcc-4.8 -O0 fft-test-asm
Self-test passed
     Size    Time per FFT (ns)
        4    min=18  mean=18  sd=0.01%
       16    min=47  mean=48  sd=0.02%
       64    min=176  mean=176  sd=0.08%
      256    min=896  mean=896  sd=0.04%
     1024    min=4790  mean=4794  sd=0.07%
     4096    min=32083  mean=32162  sd=0.13%
    16384    min=194866  mean=194966  sd=0.03%

nkurz

for CC in "gcc-4.8" \
	      "gcc-4.9" \
	      "gcc-5" "gcc-5 -flto" \
	      "gcc-6" "gcc-6 -flto" \
	      "icc-16" "icc-16 -ipo" \
	      "icc-17" "icc-17 -ipo" \
	      "clang-4.0" "clang-4.0 -flto"
do
    for CFLAGS in "-O0" "-O0 -march=native" \
			"-O1" "-O1 -march=native" \