Make this code more efficient.

llvm-svn: 40861

llvm-svn: 40859

2. Make domtree printing print dfin/dfout #'s
3. Fix the Transforms/LoopSimplify/2004-04-13-LoopSimplifyUpdateDomFrontier.ll failure from last night (in DominanceFrontier::splitBlock).

w.r.t. #3, my patches last night happened to expose the bug, but this 
has been broken since Owen's r35839 patch to LoopSimplify.  The code
was subsequently moved over from LoopSimplify into Dominators, carrying
the latent bug.  Fun stuff.

llvm-svn: 40858

llvm-svn: 40857

llvm-svn: 40856

llvm-svn: 40855

llvm-svn: 40854

llvm-svn: 40853

llvm-svn: 40852

actual argument name of the documented function.

llvm-svn: 40851

llvm-svn: 40850

llvm-svn: 40849

Lots of problems yet but some simple things work.

llvm-svn: 40847

llvm-svn: 40846

llvm-svn: 40843

This shrinks it down to something small.  On the testcase
from PR1432, this speeds up instcombine from 0.7959s to 0.5000s,
(59%)

llvm-svn: 40840

to EmptyKey.

llvm-svn: 40839

which dynamically allocates the string result.  This speeds up dse on the
testcase from PR1432 from 0.3781s to 0.1804s (2.1x).

llvm-svn: 40838

contents of the set were small, deallocate and shrink the set.  This
avoids having us to memset as much data, significantly speeding up
some pathological cases.  For example, this speeds up the verifier
from 0.3899s to 0.0763 (5.1x) on the testcase from PR1432 in a 
release build.

llvm-svn: 40837

llvm-svn: 40830

domtree by 10% and postdomtree by 17%

llvm-svn: 40829

a smallptrset.  This speeds up domtree by about 15% and postdomtree by 20%.

llvm-svn: 40828

speeds up idom by about 45% and postidom by about 33%.

Some extra precautions must be taken not to invalidate densemap iterators.

llvm-svn: 40827

DenseMap instead of an std::map.  This speeds up postdomtree
by about 25% and domtree by about 23%.  It also speeds up clients,
for example, domfrontier by 11%, mem2reg by 4% and ADCE by 6%.

llvm-svn: 40826

In the old way, we computed and inserted phi nodes for the whole IDF of 
the definitions of the alloca, then computed which ones were dead and
removed them.

In the new method, we first compute the region where the value is live,
and use that information to only insert phi nodes that are live.  This
eliminates the need to compute liveness later, and stops the algorithm
from inserting a bunch of phis which it then later removes.

This speeds up the testcase in PR1432 from 2.00s to 0.15s (14x) in a
release build and 6.84s->0.50s (14x) in a debug build.

llvm-svn: 40825

llvm-svn: 40824

measurable speedup.

llvm-svn: 40823

to the worklist, and handling the last one with a 'tail call'.  This speeds
up PR1432 from 2.0578s to 2.0012s (2.8%)

llvm-svn: 40822

mem2reg from 2.0742->2.0522s on PR1432.

llvm-svn: 40821

llvm-svn: 40820

llvm-svn: 40819

faster than with the 'local to a block' fastpath.  This speeds
up PR1432 from 2.1232 to 2.0686s (2.6%)

llvm-svn: 40818

to increment NumLocalPromoted, and didn't actually delete the
dead alloca, leading to an extra iteration of mem2reg.

llvm-svn: 40817

llvm-svn: 40816

Predsimplify fails llvm-gcc bootstrap.

llvm-svn: 40815

stored value was a non-instruction value.  Doh.

This increase the # single store allocas from 8982 to 9026, and
speeds up mem2reg on the testcase in PR1432 from 2.17 to 2.13s.

llvm-svn: 40813

and the alloca so they don't get reprocessed.

This speeds up PR1432 from 2.20s to 2.17s.

llvm-svn: 40812

  1. Check for revisiting a block before checking domination, which is faster.
  2. If the stored value isn't an instruction, we don't have to check for domination.
  3. If we have a value used in the same block more than once, make sure to remove the
     block from the UsingBlocks vector.  Not doing so forces us to go through the slow
     path for the alloca.

The combination of these improvements increases the number of allocas on the fastpath
from 8935 to 8982 on PR1432.  This speeds it up from 2.90s to 2.20s (31%)

llvm-svn: 40811

testcase in PR1432 from 6.33s to 2.90s (2.22x)

llvm-svn: 40810

a using block from the list if we handle it.  Not doing this caused us
to not be able to promote (with the fast path) allocas which have uses (whoops).

This increases the # allocas hitting this fastpath from 4042 to 8935 on the
testcase in PR1432, speeding up mem2reg by 2.6x

llvm-svn: 40809