STEP_C0          1165 ext/gd/libgd/gd_topal.c       inc0 = inc0 * (2 * STEP_C0) + STEP_C0 * STEP_C0;
STEP_C0          1196 ext/gd/libgd/gd_topal.c 	  xx0 += 2 * STEP_C0 * STEP_C0;