On Monday, 4 August 2014 at 02:31:36 UTC, John Carter wrote:
On Monday, 4 August 2014 at 02:18:12 UTC, David Bregman wrote:
His post basically says that his real life experience leads
him to believe that a static analyzer based on using
information from asserts will very likely generate a ton of
warnings/errors, because real life code is imperfect.
In other words, if you use that information to optimize
instead, you are going to get a ton of bugs, because the
asserts are inconsistent with the code.
No.
My experience says deeper optimization comes from deeper
understanding of the dataflow, with deeper understanding of the
dataflow comes stricter warnings about defective usage.
Yes, that isn't what is being proposed though. This is about
optimization, not warnings or errors.
ie. A Good compiler writer, as Walter and the gcc guys clearly
are, don't just slap in an optimization pass out of nowhere.
They are all too painfully aware that if their optimization
pass breaks anything, they will be fending off thousands of
complaints that "Optimization X broke....".
If you read the earlier threads, you will see Walter freely
admits this will break code. Actually he says that such code is
already broken. This doesn't involve new warnings, it will just
break silently. It would be very difficult to do otherwise (see
Daniel Gibson's reply to your post).
