>>>>> Vladimir Makarov writes:
Vlad> Especially I did not like David Edelhson's phrase "and no new
Vlad> private dataflow schemes will be allowed in gcc passes". It was not
Vlad> such his first expression. Such phrases are killing competition which
Vlad> is bad for gcc. What if the new specialized scheme is faster. What
Vlad> if somebody decides to write another better df infrastructure from the
Vlad> scratch to solve the coming df infrastructure problems.
First, "another better df infrastructure" is not a private
dataflow scheme. If someone else wants to rewrite it from scratch and do
a better job, be my guest. Most commercial compilers rewrite their
infrastructure every 5 to 10 years; GCC accretes kludges. The other
commercial compilers learn from their algorithms and previous design to
implement a new, maintainable infrastructure that meets the needs of all
algorithms.
Second, this has nothing to do with competition. As I and others
explained on the IRC chat, the new df is general infrastructure. If you
can speed it up more, that's great. If you need another dataflow problem
solved, add it to the infrastructure. GCC is not served well by five (5)
different dataflow solvers, each with its own quirks, bugs, duplicative
memory and duplicative maintenance. It would be a waste to improve GCC's
infrastructure and then have the hard work undermined by recreating the
duplication without good justification.
Third, I am disappointed that you chose to make this argument
personal.
David
