Value, not an Instruction, so casting is not necessary. Also,
it's theoretically possible that the Value is not an
Instruction, since WeakVH follows RAUWs.

llvm-svn: 127427

llvm-svn: 127426

after it has finished all of its reassociations, because its
habit of unlinking operands and holding them in a datastructure
while working means that it's not easy to determine when an
instruction is really dead until after all its regular work is
done. rdar://9096268.

llvm-svn: 127424

llvm-svn: 127423

llvm-svn: 127422

llvm-svn: 127420

llvm-svn: 127419

This happens a lot in clang-compiled C++ code because it adds overflow checks to operator new[]:
  unsigned *foo(unsigned n) { return new unsigned[n]; }
We can optimize away the overflow check on 64 bit targets because (uint64_t)n*4 cannot overflow.

llvm-svn: 127418

llvm-svn: 127417

llvm-svn: 127416

llvm-svn: 127413

llvm-svn: 127410

support for creating buffers that cover only a part of a file.

llvm-svn: 127409

llvm-svn: 127399

llvm-svn: 127398

llvm-svn: 127397

This makes it possible to register delegates and get callbacks when the spiller
edits live ranges.

llvm-svn: 127389

llvm-svn: 127388

llvm-svn: 127383

llvm-svn: 127382

Introduce DebugInfoProbe. This is used to monitor how llvm optimizer is treating debugging information. 
It generates output that lools like

8 times line number info lost by Scalar Replacement of Aggregates (SSAUp) 
1 times line number info lost by Simplify well-known library calls 
12 times variable info lost by Jump Threading

llvm-svn: 127381

llvm-svn: 127380

llvm-svn: 127376

llvm-svn: 127371

llvm-svn: 127369

flexible.

If it returns a register class that's different from the input, then that's the
register class used for cross-register class copies.
If it returns a register class that's the same as the input, then no cross-
register class copies are needed (normal copies would do).
If it returns null, then it's not at all possible to copy registers of the
specified register class.

llvm-svn: 127368

llvm-svn: 127366

llvm-svn: 127365

llvm-svn: 127364

llvm-svn: 127363

llvm-svn: 127362

llvm-svn: 127359

llvm-svn: 127358

llvm-svn: 127357

try to make o32 cc tests less specific to silence some buildbots. The test isn't enabled yet, this is will be done in a subsequent commit. Patch by Akira Hatanaka.

llvm-svn: 127356

The insufficient encoding information of the combined instruction confuses the decoder wrt
UQADD16.  Add extra logic to recover from that.

Fixed an assert reported by Sean Callanan

llvm-svn: 127354

command line, they'll still be seen with -help-hidden.

llvm-svn: 127353

llvm-svn: 127352

The damage done by physreg coalescing only depends on the number of instructions
the extended physreg live range covers. This fixes PR9438.

The heuristic is still luck-based, and physreg coalescing really should be
disabled completely. We need a register allocator with better hinting support
before that is possible.

Convert a test to FileCheck and force spilling by inserting an extra call. The
previous spilling behavior was dependent on misguided physreg coalescing
decisions.

llvm-svn: 127351

The test is derived from an old miscompilation of
MultiSource/Benchmarks/VersaBench/8b10b which is run regularly, so we are not
losing coverage.

llvm-svn: 127350