functional change.

llvm-svn: 60307

Note that the FoldOpIntoPhi call is dead because it's impossible for the 
first operand of a subtraction to be both a ConstantInt and a PHINode.

llvm-svn: 60306

llvm-svn: 60291

takes care of all permutations of this pattern.

llvm-svn: 60290

llvm-svn: 60289

APInt calls instead.

This fixes PR3144.

llvm-svn: 60288

only show up in code from front-ends besides llvm-gcc, like clang.

llvm-svn: 60287

llvm-svn: 60279

"For signed integers, the determination of overflow of x*y is not so simple. If
x and y have the same sign, then overflow occurs iff xy > 2**31 - 1. If they
have opposite signs, then overflow occurs iff xy < -2**31."

In this case, x == -1.

llvm-svn: 60278

overflowed on negation. This commit checks to make sure that neithe C nor X
overflows. This requires that the RHS of X (a subtract instruction) be a
constant integer.

llvm-svn: 60275

If we see that a load depends on the allocation of its memory with no
intervening stores, we now return a 'None' depedency instead of "Normal".
This tweaks GVN to do its optimization with the new result.

llvm-svn: 60267

Fix a subtle iterator invalidation bug I introduced in the last commit.

llvm-svn: 60258

a smallvector instead of a DenseMap.  This speeds up GVN by 5%
on 403.gcc.

llvm-svn: 60255

formulation that is faster and doesn't require nonLazyHelper.
Much less code.

llvm-svn: 60253

llvm-svn: 60251

former does caching, the later doesn't.  This dramatically simplifies
the logic in getDependency and getDependencyFrom.

llvm-svn: 60234

llvm-svn: 60233

query.  This makes it crystal clear what cases can escape from MemDep that
the clients have to handle.  This also gives the clients a nice simplified
interface to it that is easy to poke at.

This patch also makes DepResultTy and MemoryDependenceAnalysis::DepType
private, yay.

llvm-svn: 60231

of a pointer/int pair instead of a manually bitmangled pointer.
This forces clients to think a little more about checking the 
appropriate pieces and will be useful for internal 
implementation improvements later.

I'm not particularly happy with this.  After going through this
I don't think that the clients of memdep should be exposed to
the internal type at all.  I'll fix this in a subsequent commit.

This has no functionality change.

llvm-svn: 60230

llvm-svn: 60221

llvm-svn: 60213

predecessor is itself.  This doesn't make sense, and this is
a dead infinite loop anyway.

llvm-svn: 60210

formulation that doesn't require set lookups or scanning a set.

llvm-svn: 60203

nothing to do with dead instruction elimination.  No tests in
dejagnu depend on this, so I don't know what it was needed for.

llvm-svn: 60202

elimination to use more modern infrastructure.  Also do a bunch
of small cleanups.

llvm-svn: 60201

RecursivelyDeleteTriviallyDeadInstructions.

llvm-svn: 60196

making it use RecursivelyDeleteTriviallyDeadInstructions to do
the heavy lifting.

llvm-svn: 60195

PHIs dead if they are single-value.

llvm-svn: 60194

return a list of deleted instructions.

llvm-svn: 60193

llvm-svn: 60192

wrappers around the interesting code and use an obscure iterator
abstraction that dates back many many years.

Move EraseDeadInstructions to Transforms/Utils and name it
RecursivelyDeleteTriviallyDeadInstructions.

llvm-svn: 60191

llvm-svn: 60190

llvm-svn: 60189

llvm-svn: 60187

by 1, as well as multiply by -1.

llvm-svn: 60182

it ends up being the entry block.

llvm-svn: 60180

move the other block back up into the entry position!

llvm-svn: 60179

FindAvailableLoadedValue

llvm-svn: 60169

if it has it.

llvm-svn: 60167

llvm-svn: 60166