to avoid redundant mov out3=r44 type instructions, we need to
tell the register allocator the truth about out? registers.
FIXME: unfortunately, since the list of allocatable registers is immutable,
we can't simply 'delete r127' from the allocation order, say, if 'out0' is
used. The only correct thing we can do is have a linear order of regs:
out7, out6 ... out2, out1, out0, r32, r33, r34 ... r126, r127
and slide a 'window' of 96 registers along this line, depending on how many
of the out? regs a function actually uses. The only downside of this is
that the out? registers will be allocated _first_, which makes the
resulting assembly ugly. :( Note this in the README. Hope this gets fixed
soon. :) (note the 3rd person speech there)
llvm-svn: 21252
* Stop being pessimistic about output register allocation
* Start to handle function descriptors: compute target GPs and so on
when doing indirect calls etc. Not there yet, though. For the moment,
we try to use _indirect_ branches wherever possible, to stress test
function descriptors.
* FP divide-by-zero should work now
* add varargs (it doesn't work, though)
At this point, all of SingleSource passes (modulo C++ tests that are due
to issues with the CFE, see note in the README.) Much of MultiSource also
passes although there's still a ton of bugs around. Something for me to
work on tomorrow, then. :)
llvm-svn: 20960
Chris Lattner