Easy! Little known & seldom used technique.
Use this trick, and your problems are almost over. Seldom used, even by most professionals, and it is faster and easier than turning the logs. I'll bet many of the super-pro's on this site have never tried it!
1. Make an initial top cut, at least 1/2 way through the log. Deep enough that you won't hit the wedge when it is installed.
2. Pound in a wedge into the top. Plastic wedges work best, because they won't dull your saw when you screw up and hit them.
3. Finish the cut.
When you finish the cut, be sure that the handle of the saw contacts the ground first. Then follow through until the body of the saw is flat on the ground, then tip it down until the log is finished and you have not hit the dirt. You can tell when you have finished the cut,because the log will usually settle back down to the ground and the whole gap will open, even at the bottom.
If it is the right sized log, you can even lift the log off the ground sometimes by driving in the wedge until it opens the gap at the top. You will be amazed at how heavy a log you can lift with a little wedge and a splitting axe. This technique almost never pinches a saw, and allows you to cut up a log that is too big to roll over.
or...
If you are just cutting up little firewood sized pieces of wood, hold your saw vertical to the ground and cut PARALLEL to the ground with the tip of the bar, instead of towards the ground. When you've finished the cut, your saw will pass through into open air, rather than the dirt.
This question should probably have been posted in the arborist 101 section. The answers you get in this forum are likely to be a bit caustic for what would be considered simple questions.