llvm-svn: 12441

http://mail.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20040308/013095.html

Basically, this patch only updated the immediate dominatees of the header node
to tell them that the preheader also dominated them.  In practice, ALL
dominatees of the header node are also dominated by the preheader.

This fixes: LoopSimplify/2004-03-15-IncorrectDomUpdate.
and PR293

llvm-svn: 12434

horrible hack.

llvm-svn: 12423

llvm-svn: 12420

sin/cos/strlen calls and stuff.  This implements:
  LICM/call_sink_pure_function.ll
  LICM/call_sink_const_function.ll

llvm-svn: 12415

llvm-svn: 12406

Simplify the input/output finder.  All elements of a basic block are
instructions.  Any used arguments are also inputs.  An instruction can only
be used by another instruction.

llvm-svn: 12405

extracted, and a function that contained a single top-level loop never had
the loop extracted, regardless of how much non-loop code there was.

llvm-svn: 12403

* Don't insert a branch to the switch instruction after the call, just
  make it a single block.
* Insert the new alloca instructions in the entry block of the original
  function instead of having them execute dynamically
* Don't make the default edge of the switch instruction go back to the switch.
  The loop extractor shouldn't create new loops!
* Give meaningful names to the alloca slots and the reload instructions
* Some minor code simplifications

llvm-svn: 12402

This also implements a two minor improvements:
  * Don't insert live-out stores IN the region, insert them on the code path
    that exits the region
  * If the region is exited to the same block from multiple paths, share the
    switch statement entry, live-out store code, and the basic block.

llvm-svn: 12401

a member of the class.  While we're at it, turn the collection into a set
instead of a vector to improve efficiency and make queries simpler.

llvm-svn: 12400

the command line, and the single loop extractor, usable by bugpoint

llvm-svn: 12390

llvm-svn: 12385

be non-empty!  This fixes LowerSwitch/2004-03-13-SwitchIsDefaultCrash.ll

llvm-svn: 12384

llvm-svn: 12382

Require 'simplified' loops, not just raw natural loops.  This fixes
CodeExtractor/2004-03-13-LoopExtractorCrash.ll

llvm-svn: 12381

loop information won't see it, and we could have unreachable blocks pointing to
the non-header node of blocks in a natural loop.  This isn't tidy, so have the
loopsimplify pass clean it up.

llvm-svn: 12380

curly braceage

llvm-svn: 12378

Make sure that the file interface header (IPO.h) is included first
remove dead #incldue

llvm-svn: 12375

llvm-svn: 12373

llvm-svn: 12372

llvm-svn: 12368

Fix InstCombine/2004-03-13-InstCombineInfLoop.ll which caused an infinite
loop compiling (I think) povray.

llvm-svn: 12365

 * Be a lot more accurate about what the effects will be when inlining a call
   to a function when an argument is an alloca.
 * Dramatically reduce the penalty for inlining a call in a large function.
   This heuristic made it almost impossible to inline a function into a large
   function, no matter how small the callee is.

llvm-svn: 12363

On the testcase from GCC PR12440, which has a LOT of loops (1392 of which require
preheaders to be inserted), this speeds up the loopsimplify pass from 1.931s to
0.1875s.  The loop in question goes from 1.65s -> 0.0097s, which isn't bad. All of
these times are a debug build.

This adds a dependency on DominatorTree analysis that was not there before, but
we always had dominatortree available anyway, because LICM requires both loop
simplify and DT, so this doesn't add any extra analysis in practice.

llvm-svn: 12362

llvm-svn: 12355

llvm-svn: 12353

llvm-svn: 12319

llvm-svn: 12318

llvm-svn: 12317

llvm-svn: 12225

llvm-svn: 12224

llvm-svn: 12221

This allows pointers to aggregate objects, whose elements are only read, to
be promoted and passed in by element instead of by reference.  This can
enable a LOT of subsequent optimizations in the caller function.

It's worth pointing out that this stuff happens a LOT of C++ programs, because
objects in templates are generally passed around by reference.  When these
templates are instantiated on small aggregate or scalar types, however, it is
more efficient to pass them in by value than by reference.

This transformation triggers most on C++ codes (e.g. 334 times on eon), but
does happen on C codes as well.  For example, on mesa it triggers 72 times,
and on gcc it triggers 35 times.  this is amazingly good considering that
we are using 'basicaa' so far.

llvm-svn: 12202

llvm-svn: 12200

llvm-svn: 12198

a zero value is the most likely way to cause further simplification, so we do it.

llvm-svn: 12197

llvm-svn: 12195

variables.

llvm-svn: 12193

llvm-svn: 12086