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

On Windows, replace each occurrence of '\' by '\\' on the replacement string. This is necessary to prevent re.sub from replacing escape sequences occurring in path.

For example:

llvm\tools\clang\test
was replaced by
llvm <tab> ools\clang <tab> est

llvm-svn: 123070

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

Add a unnamed_addr bit to global variables and functions. This will be used
to indicate that the address is not significant and therefore the constant
or function can be merged with others.

If an optimization pass can show that an address is not used, it can set this.

Examples of things that can have this set by the FE are globals created to
hold string literals and C++ constructors.

Adding unnamed_addr to a non-const global should have no effect unless
an optimization can transform that global into a constant.

Aliases are not allowed to have unnamed_addr since I couldn't figure
out any use for it.

llvm-svn: 123063

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

llvm-svn: 123059

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

llvm-svn: 123051

llvm-svn: 123048

Instead encode llvm IR level property "HasSideEffects" in an operand (shared
with IsAlignStack). Added MachineInstrs::hasUnmodeledSideEffects() to check
the operand when the instruction is an INLINEASM.

This allows memory instructions to be moved around INLINEASM instructions.

llvm-svn: 123044

This was suggested by Edmund Grimley Evans in pr8411.

llvm-svn: 123043

llvm-svn: 123042

llvm-svn: 123040

llvm-svn: 123039

This means avoid using uint32_t. This patch reverts r112200 and fixes original  problem by fixing argument type in lto.cpp.

llvm-svn: 123038

llvm-svn: 123036

Patch by Tim Northover.

llvm-svn: 123035

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

Enable live debug variables pass.

llvm-svn: 123032

llvm-svn: 123031

llvm-svn: 123030

instead.

llvm-svn: 123028

every BranchInst has a fixed number of operands.

llvm-svn: 123027

llvm-svn: 123026

llvm-svn: 123025

Revert r122955. It seems using movups to lower memcpy can cause massive regression (even on Nehalem) in edge cases. I also didn't see any real performance benefit.

llvm-svn: 123015

Rename lisp-like functions as suggested by Gabor Greif as loooong time
ago.  This is both easier to learn and easier to read.

llvm-svn: 123001

llvm-svn: 122999

llvm-svn: 122997

Also fix an off-by-one in SelectionDAGBuilder that was preventing shuffle
vectors from being translated to EXTRACT_SUBVECTOR.
Patch by Tim Northover.

The test changes are needed to keep those spill-q tests from testing aligned
spills and restores.  If the only aligned stack objects are spill slots, we
no longer realign the stack frame.  Prior to this patch, an EXTRACT_SUBVECTOR
was legalized by loading from the stack, which created an aligned frame index.
Now, however, there is nothing except the spill slot in the stack frame, so
I added an aligned alloca.

llvm-svn: 122995