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

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: 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

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: 127365

llvm-svn: 127362

llvm-svn: 127359

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

llvm-svn: 127349

This helps cases like 2008-07-19-movups-spills.ll, but doesn't have an obvious impact on benchmarks

llvm-svn: 127347

Add createELFObjectTargetWriter method to TargetAsmBackend, which enables construction of non-standard ELFObjectWriters that can be used in MCJIT.

llvm-svn: 127346

llvm-svn: 127343

When ExactBECount is a constant, use it for MaxBECount.
When MaxBECount cannot be computed, replace it with ExactBECount.
Fixes PR9424.

llvm-svn: 127342

llvm-svn: 127340

llvm-svn: 127335

llvm-svn: 127331

llvm-svn: 127328

Thanks Duncan Sands!

llvm-svn: 127323

alloca as both integer and floating-point vectors of the same size. Bugpoint is
not cooperating with me, but I'll try to find a manual testcase tomorrow.

llvm-svn: 127320

gave up when I realized I couldn't come up with a good name for what the
refactored function would be, to describe what it does.

This is PR9343 test12, which is test3 with arguments reordered. Whoops!

llvm-svn: 127318

a union of a float, <2 x float>, and <4 x float>. This mostly comes up with the
use of vector intrinsics, especially in NEON when programmers know the layout of
the register file. This enables codegen to eliminate a lot of the subregister
traffic it would otherwise generate.

This commit only enables this for a small number of floating-point cases, but a
lot more integer cases. I assume this is okay for all ports, but I did not do
extensive testing of the quality of code involving i512 vectors and the like. If
there is a use case where this generates worse code than before, let me know and
we can scale it back.

This fixes <rdar://problem/9036264>.

llvm-svn: 127317