On Sun, 2009-11-15 at 16:12 -0700, David Brownell wrote: > On Sunday 15 November 2009, Zach Welch wrote: > > > > > > Or maybe I was. Given that it copies everything, why > > > is there code *after* the copy mangling the last byte? > > > Wouldn't that only be correct when the code copied > > > all but the trailing partial byte? > > > > It masks the last byte, ensuring any trailing bits are 0. > > Without it, the bits after the 'trailing' will have been copied beyond > > the bits intended: copy buf=0xff, len=3 should give 0x07 and not 0xff. > > Right? That's what the old code did, in a really confusing manner. > > Chalk it up to a flakey model for handling bitfields, then. > > My model is that if I've got a buffer, and am told to > stuff N bits into it at a particular location, then > only N bits will change. > > Instead, we seem to change N ... then zero up to seven > bits in the last byte.
Hey... I'm not defending it! :) Further changes can come after this series has been pushed, when we can audit all of its callers. I expect many opportunities for optimization as we move up the stack. --Z _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development
