Improve the return slot optimization to be both more aggressive (not limited to sret parameters), and 
safer (when the passed pointer might be invalid).  Thanks to Duncan and Chris for the idea behind this, 
and extra thanks to Duncan for helping me work out the trap-safety.

llvm-svn: 48280

llvm-svn: 48233

Right now, the pass does not optimize tail recursions 
involving multiple return values.

llvm-svn: 48228

llvm-svn: 48227

llvm-svn: 48210

llvm-svn: 48109

llvm-svn: 48106

and also update the cloning interface's major user, the loop optimizations.

llvm-svn: 48088

llvm-svn: 48047

under modulo (overflow). Fixes PR1933.

llvm-svn: 47987

a union containing a vector and an array whose elements were smaller than
the vector elements.  this means we need to compile the load of the 
array elements into an extract element plus a truncate.

llvm-svn: 47752

functionality change.

llvm-svn: 47751

llvm-svn: 47750

in an invalid transformation.

llvm-svn: 47639

llvm-svn: 47615

try to simplify them.

llvm-svn: 47610

llvm-svn: 47599

operands into inline asm block.

llvm-svn: 47589

not safe.  This is fixed by more aggressively checking that the return slot is
not used elsewhere in the function.

llvm-svn: 47544

Fix an issue where GVN would try to use an instruction before its definition when performing return slot optimization.

llvm-svn: 47541

stuff into ParamAttrsList.h.  Per feedback from
ParamAttrs changes.

llvm-svn: 47504

llvm-svn: 47478

llvm-svn: 47382

llvm-svn: 47375

llvm-svn: 47371

llvm-svn: 47367

llvm-svn: 47364

for adding alignment info, not there yet).  Clean up
interfaces to reference ParameterAttributes consistently.

llvm-svn: 47342

could work don't work fully.  This fixes PR1705.  Oh yeah, we don't have
packed types anymore either ;-)

llvm-svn: 47322

Refactor this method a bit, and correct a test that was completely wrong but happened to work out anyways. :-)

llvm-svn: 47321

llvm-svn: 47320

llvm-svn: 47319

llvm-svn: 47318

and add some others that should have been in from the first place.  Document the whole thing better.

llvm-svn: 47315

can be a SNaN.  We could be more aggressive and turn this into 
unreachable, but that is less nice, and not really worth it.

llvm-svn: 47313

At some point in the future, this check will become smarter.

llvm-svn: 47310

over all the parameters of the callee looking for it.

llvm-svn: 47309

to apply to a memcpy into processInstruction.  Also, fix a bug in the check due to
missing braces.

llvm-svn: 47307

Fix Transforms/GVN/memcpy.ll, which Chris broke in r47275 by reordering the branches.  memcpy's are a kind of CallInst.

llvm-svn: 47305

llvm-svn: 47287