Add support to GVN for performing sret return slot optimization.  This means that, if an sret function tail calls
another sret function, it should pass its own sret parameter to the tail callee, allowing it to fill in the correct
return value.  llvm-gcc does not emit this by default.  Instead, it allocates space in the caller for the sret of
the tail call and then uses memcpy to copy the result into the caller's sret parameter.  This optimization detects
and optimizes that case.

llvm-svn: 47265

llvm-svn: 47111

bugs fixed.  This now passes PPC bootstrap.

llvm-svn: 47026

checks for a malloc/alloca immediately followed by a load.

llvm-svn: 47006

http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20080128/057882.html

This is causing a miscompilation on PPC G5 and just now seeing it on iMac x86-64.

llvm-svn: 46822

llvm-svn: 46693

llvm-svn: 45418

Fix several cache coherence bugs in MemDep/GVN that were found.  Also add some (disabled) debugging code
to make such problems easier to diagnose in the future, written by Duncan Sands.

llvm-svn: 44695

into alias analysis.  This meant updating the API
which now has versions of the getModRefBehavior,
doesNotAccessMemory and onlyReadsMemory methods
which take a callsite parameter.  These should be
used unless the callsite is not known, since in
general they can do a better job than the versions
that take a function.  Also, users should no longer
call the version of getModRefBehavior that takes
both a function and a callsite.  To reduce the
chance of misuse it is now protected.

llvm-svn: 44487

llvm-svn: 44437

llvm-svn: 44325

llvm-svn: 44323

llvm-svn: 43147

speedup for GVN.

llvm-svn: 42185

Add a new DenseMapInfo::isEqual method to allow clients to redefine
the equality predicate used when probing the hash table.

llvm-svn: 42042

llvm-svn: 41998

llvm-svn: 41131

llvm-svn: 41129

they're not related to eliminating a load.

llvm-svn: 41081

llvm-svn: 41080

llvm-svn: 41078

the function.

llvm-svn: 41077

llvm-svn: 40961

llvm-svn: 40946

llvm-svn: 40909

llvm-svn: 40791

llvm-svn: 40776

llvm-svn: 40750

llvm-svn: 40746

llvm-svn: 40692

llvm-svn: 40655

removal of redundant phis.

llvm-svn: 40650

llvm-svn: 40642

llvm-svn: 40607

use up the entire 32-bit address space.

llvm-svn: 40596

llvm-svn: 40595

almost the same things from LCSSA.

llvm-svn: 40540

llvm-svn: 40503

llvm-svn: 40498

llvm-svn: 40497