phi translation of complex expressions like &A[i+1].  This has the
following benefits:

1. The phi translation logic is all contained in its own class with
   a strong interface and verification that it is self consistent.

2. The logic is more correct than before.  Previously, if intermediate
   expressions got PHI translated, we'd miss the update and scan for
   the wrong pointers in predecessor blocks.  @phi_trans2 is a testcase
   for this.

3. We have a lot less code in memdep.

We can handle phi translation across blocks of things like @phi_trans3,
which is pretty insane :).

This patch should fix the miscompiles of 255.vortex, and I tested it 
with a bootstrap of llvm-gcc, llvm-test and dejagnu of course.

llvm-svn: 90926

llvm-svn: 90866

I'm not aware that this does anything significant on its own, but it's
needed for another patch that I'm working on.

llvm-svn: 90864

llvm-svn: 90836

llvm-svn: 90708

because clang lowers nontrivial automatic struct/array inits to memcpy from
a global array.

llvm-svn: 90698

llvm-svn: 90697

short x(short *A) {
  memset(A, 1, sizeof(*A)*100);
  return A[42];
}

to 'return 257' instead of doing the load.  

llvm-svn: 90695

integers that are constant except for a single bit (the same n-th bit in each).

llvm-svn: 90646

llvm-svn: 90603

llvm-svn: 90601

llvm-svn: 90487

llvm-svn: 90408

Patch by Howard Hinnant!

llvm-svn: 90365

per Chris' comments.  Adjust testcases to match.

llvm-svn: 90304

llvm-svn: 90299

llvm-svn: 90298

llvm-svn: 90297

precisely, which prevents us from infinitely peeling the loop.

llvm-svn: 90211

llvm-svn: 90097

llvm-svn: 90089

fix bugs exposed by the tests.  Testcases from Alastair Lynn!

llvm-svn: 90056

llvm-svn: 90046

handle cases like this:
void test(int N, double* G) {
  long j;
  for (j = 1; j < N - 1; j++)
      G[j+1] = G[j] + G[j+1];
}

where G[1] isn't live into the loop.

llvm-svn: 90041

inserted instructions.  No functionality change until someone starts using it.

llvm-svn: 90039

to inform GVN about the newly inserted values.  This fixes 
PR5631.

llvm-svn: 90022

fixes PR5630 and sets the stage for the next phase of goodness (testcase
pending).

llvm-svn: 90019

llvm-svn: 90011

array indexes.  The "complex" case of SRoA still handles them, and correctly.

This fixes a weirdness where we'd correctly avoid transforming A[0][42] if
the 42 was too large, but we'd only do it if it was one gep, not two separate
ones.

llvm-svn: 90007

where it is not available.  It's unclear how to get this inserted 
computation into GVN's scalar availability sets, Owen, help? :)

llvm-svn: 89997

translation done by memdep, and reenable gep translation 
again.

llvm-svn: 89992

SimplifyGEPInst method in InstructionSimplify.h.  No functionality change.

llvm-svn: 89980

llvm-svn: 89972

generates store to undef and some generates store to null as the idiom
for undefined behavior.  Since simplifycfg zaps both, don't remove the
undefined behavior in instcombine.

llvm-svn: 89971

by Alastair Lynn.

llvm-svn: 89970

llvm-svn: 89844

llvm-svn: 89758

adjacent uses of a dead basic block from the same user. This fixes PR5596.

llvm-svn: 89658

llvm-svn: 89645

llvm-svn: 89644