llvm-svn: 11719

Also make it less aggressive as the current implementation breaks in
some cases.

llvm-svn: 11696

1. LiveIntervals now implement a 4 slot per instruction model. Load,
   Use, Def and a Store slot. This is required in order to correctly
   represent caller saved register clobbering on function calls,
   register reuse in the same instruction (def resues last use) and
   also spill code added later by the allocator. The previous
   representation (2 slots per instruction) was insufficient and as a
   result was causing subtle bugs.

2. Fixes in spill code generation. This was the major cause of
   failures in the test suite.

3. Linear scan now has core support for folding memory operands. This
   is untested and not enabled (the live interval update function does
   not attempt to fold loads/stores in instructions).

4. Lots of improvements in the debugging output of both live intervals
   and linear scan. Give it a try... it is beautiful :-)

In summary the above fixes all the issues with the recent reserved
register elimination changes and get the allocator very close to the
next big step: folding memory operands.

llvm-svn: 11654

given a register.

llvm-svn: 11608

llvm-svn: 11520

llvm-svn: 11476

any test cases :-)

llvm-svn: 11032

llvm-svn: 11029

Simplification of LiveIntervals::Interval::overlaps() and addition of
examples to overlaps() and liveAt() to make them clearer.

llvm-svn: 11028

when joining we need to check if we overlap with the second interval
or any of its aliases.

Also make joining intervals the default.

llvm-svn: 10973

is a move between two registers, at least one of the registers is
virtual and the two live intervals do not overlap.

This results in about 40% reduction in intervals, 30% decrease in the
register allocators running time and a 20% increase in peephole
optimizations (mainly move eliminations).

The option can be enabled by passing -join-liveintervals where
appropriate.

llvm-svn: 10965

LiveIntervals::Interval::expiredAt() and simplify regalloc code.

llvm-svn: 10894

when we join intervals and one of the two will need to be removed.

llvm-svn: 10892

LiveVariables.

llvm-svn: 10830

which denotes the register we would like to be assigned to (virtual or
physical). In register allocation, if this hint exists and we can map
it to a physical register (it is either a physical register or it is a
virtual register that already got assigned to a physical one) we use
that register if it is available instead of a random one in the free
pool.

llvm-svn: 10634

nesting level when computing it. Right now the allocator uses:

    w = sum_over_defs_uses( 10 ^ nesting level );

llvm-svn: 10569

for live ranges that fall into assigned registers' holes.

llvm-svn: 10566

llvm-svn: 10511

Move some of the longer LiveIntervals::Interval method out of the
header and add debug information to them. Fix bug and simplify range
merging code.

llvm-svn: 10509

llvm-svn: 10290

Merging the linear scan register allocator in trunk. It currently passes most tests under test/Programs/SingleSource/Benchmarks/Shootout so development will continue on trunk. The allocator is not enabled by default. You will need to pass -regallo=linearscan to lli or llc to use it.

llvm-svn: 10103