that it was leaving in loops after rotation (between the original latch
block and the original header.

With this change, it is possible for rotated loops to have just a single
basic block, which is useful.

llvm-svn: 123075

loop info.

llvm-svn: 123074

llvm-svn: 123073

1. Rip out LoopRotate's domfrontier updating code.  It isn't
   needed now that LICM doesn't use DF and it is super complex
   and gross.
2. Make DomTree updating code a lot simpler and faster.  The 
   old loop over all the blocks was just to find a block??
3. Change the code that inserts the new preheader to just use
   SplitCriticalEdge instead of doing an overcomplex 
   reimplementation of it.

No behavior change, except for the name of the inserted preheader.

llvm-svn: 123072

llvm-svn: 123071

and latch blocks.  Reorder entry conditions to make hte pass faster
and more logical.

llvm-svn: 123069

llvm-svn: 123068

that are just passed to one function.

llvm-svn: 123067

to violate LCSSA form

llvm-svn: 123066

llvm-svn: 123065

they all ready do). This removes two dominator recomputations prior to isel,
which is a 1% improvement in total llc time for 403.gcc.

The only potentially suspect thing is making GCStrategy recompute dominators if
it used a custom lowering strategy.

llvm-svn: 123064

top of subloop headers, as the phi uses logically occur outside of the subloop.

llvm-svn: 123062

llvm-svn: 123061

them into the loop preheader, eliminating silly instructions like
"icmp i32 0, 100" in fixed tripcount loops.  This also better exposes the 
bigger problem with loop rotate that I'd like to fix: once this has been
folded, the duplicated conditional branch *often* turns into an uncond branch.

Not aggressively handling this is pessimizing later loop optimizations 
somethin' fierce by making "dominates all exit blocks" checks fail.

llvm-svn: 123060

1. Take a flags argument instead of a bool.  This makes
   it more clear to the reader what it is used for.
2. Add a flag that says that "remapping a value not in the
   map is ok".
3. Reimplement MapValue to share a bunch of code and be a lot
   more efficient.  For lookup failures, don't drop null values
   into the map.
4. Using the new flag a bunch of code can vaporize in LinkModules
   and LoopUnswitch, kill it.

No functionality change.

llvm-svn: 123058

map from ValueMapper.h (giving us access to its utilities)
and add a fastpath in the loop rotation code, avoiding expensive
ssa updator manipulation for values with nothing to update.

llvm-svn: 123057

X = sext x; x >s c ? X : C+1 --> X = sext x; X <s C+1 ? C+1 : X
X = sext x; x <s c ? X : C-1 --> X = sext x; X >s C-1 ? C-1 : X
X = zext x; x >u c ? X : C+1 --> X = zext x; X <u C+1 ? C+1 : X
X = zext x; x <u c ? X : C-1 --> X = zext x; X >u C-1 ? C-1 : X
X = sext x; x >u c ? X : C+1 --> X = sext x; X <u C+1 ? C+1 : X
X = sext x; x <u c ? X : C-1 --> X = sext x; X >u C-1 ? C-1 : X

Instead of calculating this with mixed types promote all to the
larger type. This enables scalar evolution to analyze this
expression. PR8866

llvm-svn: 123034

llvm-svn: 123033

llvm-svn: 123030

llvm-svn: 123025

This happens when we take the (non-constant) length from a malloc.

llvm-svn: 122961

InstCombine: If we call llvm.objectsize on a malloc call we can replace it with the size passed to malloc.

llvm-svn: 122959

llvm-svn: 122958

OptimizeInst() so that they can be used on a worklist instruction.

llvm-svn: 122945

llvm-svn: 122944

into a separate function, so that it can be called from a loop using a worklist
rather than a loop traversing a whole basic block.

llvm-svn: 122943

Simplify RALinScan::DowngradeRegister with TRI::getOverlaps while we are there.

llvm-svn: 122940

worklist, the key will need to become std::pair<BasicBlock*, Value*>.

llvm-svn: 122932

llvm-svn: 122891

regressing code quality.

llvm-svn: 122887

llvm-svn: 122876

step is to only process instructions in subloops if they have been modified by
an earlier simplification.

llvm-svn: 122869

skipping them, but it should probably use a worklist and only revisit those
instructions in subloops that have actually changed. It should probably also
use a worklist after the first iteration like instsimplify now does. Regardless,
it's only 0.3% of opt -O2 time on 403.gcc if it replaces the instcombine placed
in the middle of the loop passes.

llvm-svn: 122868

Don't bother value numbering instructions with void types in GVN. In theory this should allow us to insert
fewer things into the value numbering maps, but any speedup is beneath the noise threshold on my machine
on 403.gcc.

llvm-svn: 122844

llvm-svn: 122828

llvm-svn: 122827

llvm-svn: 122826

Clarify terminology, settling on referring to what was the "number table" as the "leader table", and
rename methods to make it much more clear what they're doing.

llvm-svn: 122823

llvm-svn: 122822

case where a static caller is itself inlined everywhere else, and
thus may go away if it doesn't get too big due to inlining other
things into it.  If there are references to the caller other than
calls, it will not be removed; account for this.
This results in same-day completion of the case in PR8853.

llvm-svn: 122821