------- Comment #8 from hjl at lucon dot org 2007-05-21 21:36 ------- According to the comment, before the change, we performed
[evaluate loop bounds and step] count = (to + step - from) / step; dovar = from; for (;;) { body; cycle_label: dovar += step count--; if (count <=0) goto exit_label; } exit_label: After the change, we did [evaluate loop bounds and step] empty = (step > 0 ? to < from : to > from); countm1 = (to - from) / step; dovar = from; if (empty) goto exit_label; for (;;) { body; cycle_label: dovar += step countm1--; if (countm1 ==0) goto exit_label; } exit_label: Didn't we do one loop less than before? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31399