llvm-svn: 37623

1. Consider all possible ifcvt cases at once. No longer restricted to bottom
   up iterative approach.
2. Sort all possible cases based on a cost function. Perform the most profitable
   ones first invalidate others that target the same blocks.
3. Fixed a number of bugs related to block duplication.

llvm-svn: 37613

llvm-svn: 37607

llvm-svn: 37599

llvm-svn: 37593

llvm-svn: 37590

llvm-svn: 37581

If BB is predicated, invalidate its predecessor(s) which would if-convert it. It needs to be re-analyzed.

llvm-svn: 37580

llvm-svn: 37577

llvm-svn: 37575

llvm-svn: 37566

llvm-svn: 37565

llvm-svn: 37543

llvm-svn: 37537

llvm-svn: 37531

llvm-svn: 37529

llvm-svn: 37524

llvm-svn: 37523

llvm-svn: 37518

llvm-svn: 37503

ifcvt a triangle: don't merge ifcvt block with rejoin block if it can fall through to it. If merged, the resulting block is not a candidate for iterative ifcvting since it contains both predicated and non-predicated code.

llvm-svn: 37487

llvm-svn: 37485

Evan, please check that this is in fact correct.

llvm-svn: 37471

llvm-svn: 37467

If a unconditional branch is added to branch to the false path during ifcvt, the predicated block cannot be iteratively ifcvted.

llvm-svn: 37456

llvm-svn: 37451

llvm-svn: 37449

llvm-svn: 37444

llvm-svn: 37441

llvm-svn: 37440

llvm-svn: 37433

If the predicated block requires an early exit, end the block there and add a unconditional branch to false block. AnalyzeBranch() does not understand early exits.

llvm-svn: 37430

llvm-svn: 37429

llvm-svn: 37420

Let IfConverter loose. Allow more aggressive subsumptions; reorder basic blocks to expose more ifcvt opportunities; code clean up and fixes.

llvm-svn: 37409

llvm-svn: 37387

Ifcvt triangle: don't ifcvt 'true' BB if it has other predecessors; don't merge 'false' BB if it has other predecessors.

llvm-svn: 37382

Remove a bogus check. Even terminators in a ifcvt need to be predicated. Unconditional branches can usually be converted to conditional ones.

llvm-svn: 37380

llvm-svn: 37379

llvm-svn: 37374