This loop is quadratic in the capacity for a DenseMap:

  while(!map.empty())
    map.erase(map.begin());

Instead we now do a normal begin() - end() iteration followed by map.clear().
That also has the nice sideeffect of shrinking the map capacity on demand.

llvm-svn: 103747

llvm-svn: 103739

This causes way more identity copies to be generated, ripe for coalescing.

llvm-svn: 103686

llvm-svn: 103685

The X86 floating point stack pass and others depend on good kill flags.

llvm-svn: 103635

llvm-svn: 103530

llvm-svn: 103528

llvm-svn: 103522

This allows us to add accurate kill markers, something the scavenger likes.
Add some more tests from ARM that needed this.

llvm-svn: 103521

closure after allocating all blocks.

Add a few more test cases for -regalloc=fast.

llvm-svn: 103500

Sorry for the big change. The path leading up to this patch had some TableGen
changes that I didn't want to commit before I knew they were useful. They
weren't, and this version does not need them.

The fast register allocator now does no liveness calculations. Instead it relies
on kill flags provided by isel. (Currently those kill flags are also ignored due
to isel bugs). The allocation algorithm is supposed to work with any subset of
valid kill flags. More kill flags simply means fewer spills inserted.

Registers are allocated from a working set that contains no aliases. That means
most allocations can be done directly without expensive alias checks. When the
working set runs out of registers we do the full alias check to find new free
registers.

llvm-svn: 103488

llvm-svn: 103450

llvm-svn: 103193

This actually makes everything slower, but the plan is to have isel add <kill>
flags the way it is already adding <dead> flags. Then LiveVariables can be
removed again.

When ignoring the time spent in LiveVariables, -regalloc=fast is now twice as
fast as -regalloc=local.

llvm-svn: 102034

So far this is just a clone of -regalloc=local that has been lobotomized to run
25% faster. It drops the least-recently-used calculations, and is just plain
stupid when it runs out of registers.

The plan is to make this go even faster for -O0 by taking advantage of the short
live intervals in unoptimized code. It should not be necessary to calculate
liveness when most virtual registers are killed 2-3 instructions after they are
born.

llvm-svn: 102006

Revert "Use a simpler data structure to calculate the least recently used register in RegAllocLocal."

This reverts commit 101392. It broke a buildbot.

llvm-svn: 101595

This makes the local register allocator about 20% faster.

llvm-svn: 101574

llvm-svn: 100709

llvm-svn: 99989

llvm-svn: 98838

llvm-svn: 98604

"used outside of the block". If the block ends in a return, then it won't be
used outside of it.

llvm-svn: 98599

at older buildbot messages, I see the failure predates
this patch.

llvm-svn: 96307

but it's harder to believe it's the other candidate,
so reverting.  Temporarily I hope.

llvm-svn: 96303

llvm-svn: 96294

llvm-svn: 96207

llvm-svn: 95730

into TargetOpcodes.h.  #include the new TargetOpcodes.h
into MachineInstr.  Add new inline accessors (like isPHI())
to MachineInstr, and start using them throughout the 
codebase.

llvm-svn: 95687

llvm-svn: 95183

buildbot failure.

llvm-svn: 95103

as output.  Needed for (functional) correctness in inline asm,
and should be generally beneficial.  7361612.

llvm-svn: 95050

llvm-svn: 94866

llvm-svn: 92595

in local register allocator.  If a reg-reg copy has a phys reg
input and a virt reg output, and this is the last use of the phys
reg, assign the phys reg to the virt reg.  If a reg-reg copy has
a phys reg output and we need to reload its spilled input, reload
it directly into the phys reg than passing it through another reg.

Following 76208, there is sometimes no dependency between the def of
a phys reg and its use; this creates a window where that phys reg
can be used for spilling (this is true in linear scan also).  This
is bad and needs to be fixed a better way, although 76208 works too
well in practice to be reverted.  However, there should normally be
no spilling within inline asm blocks.  The patch here goes a long way
towards making this actually be true.

llvm-svn: 91485

Add a bool flag to StackObjects telling whether they reference spill
slots.  The AsmPrinter will use this information to determine whether to
print a spill/reload comment.

Remove default argument values.  It's too easy to pass a wrong argument
value when multiple arguments have default values.  Make everything
explicit to trap bugs early.

Update all targets to adhere to the new interfaces..

llvm-svn: 87022

VISIBILITY_HIDDEN removal.

llvm-svn: 85043

Chris claims we should never have visibility_hidden inside any .cpp file but
that's still not true even after this commit.

llvm-svn: 85042

Distinquish stack slots from other stack objects. They (and fixed objects) get FixedStack PseudoSourceValues.

llvm-svn: 84326

llvm-svn: 79758

llvm-svn: 77754