If you disagree with my decisions, feel free to send me a message
explaining why you think that the decision was inappropriate. I will
consider your position, but you will have to be convincing in order to
change my mind. To be convincing, make sure you quantify the win: it
you want me to believe that your optimization is worthwhile tell me
how much it improves a well-known benchmark.
The following changes will be postponed until GCC 3.6. These changes
either provide too little benefit, are too risky, or will take too
much time to complete.
...
* Vectorizer misaligned-loads support [Naishlos]
Let me try to convince you to change this decision:
1. Alignment is the number one limiting factor for vectorization on
mainline right now. Without this we can't vectorize anything that uses
pointers, for example. Together with the patches for unknown loop bound and
peeling for aligning a store (proposals that were accepted for 3.5), we
will be able to vectorize loops of the following (very basic and very
common) form:
"while (--n) *q++ = *a++ + *b++".
2. Risk-free. It is entirely encapsulated within -ftree-vectorize which is
disabled by default (so no risks if not explicitly enabled).