definition for it. In that case, we want to wait for the potential definition
before we create a symbol for it.

llvm-svn: 153859

llvm-svn: 153857

rather than a bitfield, a great suggestion by Chris during code review.

There is still quite a bit of cruft in the interface, but that requires
sorting out some awkward uses of the cost inside the actual inliner.

No functionality changed intended here.

llvm-svn: 153853

llvm-svn: 153852

llvm-svn: 153851

llvm-svn: 153850

1. Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B))
   (and also scalar_to_vector).

2. Xor/and/or are indifferent to the swizzle operation (shuffle of one src).
   Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A, B))

3. Optimize swizzles of shuffles:  shuff(shuff(x, y), undef) -> shuff(x, y).

4. Fix an X86ISelLowering optimization which was very bitcast-sensitive.

Code which was previously compiled to this:

movd    (%rsi), %xmm0
movdqa  .LCPI0_0(%rip), %xmm2
pshufb  %xmm2, %xmm0
movd    (%rdi), %xmm1
pshufb  %xmm2, %xmm1
pxor    %xmm0, %xmm1
pshufb  .LCPI0_1(%rip), %xmm1
movd    %xmm1, (%rdi)
ret

Now compiles to this:

movl    (%rsi), %eax
xorl    %eax, (%rdi)
ret

llvm-svn: 153848

llvm-svn: 153846

The 440 and A2 cores have detailed itineraries, and this allows them to be
fully used to maximize throughput.

llvm-svn: 153845

llvm-svn: 153844

Post-RA scheduling gives a significant performance improvement on
the embedded cores, so turn it on. Using full anti-dep. breaking is
important for FP-intensive blocks, so turn it on (just on the
embedded cores for now; this should also be good on the 970s because
post-ra scheduling is all that we have for now, but that should have
more testing first).

llvm-svn: 153843

This adds a full itinerary for IBM's PPC64 A2 embedded core. These
cores form the basis for the CPUs in the new IBM BG/Q supercomputer.

llvm-svn: 153842

Use SequenceToOffsetTable to create instruction name table. Saves space particularly on X86 where AVX instructions just add a 'v' to the front of other instructions.

llvm-svn: 153841

This also avoids emitting the information twice, which led to code bloat. On i386-linux-Release+Asserts
with all targets built this change shaves a whopping 1.3 MB off clang. The number is probably exaggerated
by recent inliner changes but the methods were already enormous with the old inline cost computation.

The DWARF reg -> LLVM reg mapping doesn't seem to have holes in it, so it could be a simple lookup table.
I didn't implement that optimization yet to avoid potentially changing functionality.

There is still some duplication both in tablegen and the generated code that should be cleaned up eventually.

llvm-svn: 153837

As a side note, I really dislike array_pod_sort... Do we really still
care about any STL implementations that get this so wrong? Does libc++?

llvm-svn: 153834

always-inlining is disabled: recursive functions and indirectbr.

llvm-svn: 153833

a single missing character. Somehow, this had gone untested. I've added
tests for returns-twice logic specifically with the always-inliner that
would have caught this, and fixed the bug.

Thanks to Matt for the careful review and spotting this!!! =D

llvm-svn: 153832

test and FileCheck.

llvm-svn: 153831

llvm-svn: 153827

llvm-svn: 153825

Loads and stores can have different pipeline behavior, especially on
embedded chips. This change allows those differences to be expressed.
Except for the 440 scheduler, there are no functionality changes.
On the 440, the latency adjustment is only by one cycle, and so this
probably does not affect much. Nevertheless, it will make a larger
difference in the future and this removes a FIXME from the 440 itin.

llvm-svn: 153821

llvm-svn: 153820

llvm-svn: 153818

This is the CodeGen equivalent of r153747. I tested that there is not noticeable
performance difference with any combination of -O0/-O2 /-g when compiling
gcc as a single compilation unit.

llvm-svn: 153817

Dynamic linking on PPC64 has had problems since we had to move the top-down
hazard-detection logic post-ra. For dynamic linking to work there needs to be
a nop placed after every call. It turns out that it is really hard to guarantee
that nothing will be placed in between the call (bl) and the nop during post-ra
scheduling. Previous attempts at fixing this by placing logic inside the
hazard detector only partially worked.

This is now fixed in a different way: call+nop codegen-only instructions. As far
as CodeGen is concerned the pair is now a single instruction and cannot be split.
This solution works much better than previous attempts.

The scoreboard hazard detector is also renamed to be more generic, there is currently
no cpu-specific logic in it.

llvm-svn: 153816

llvm-svn: 153815

the very high overhead of the complex inline cost analysis when all it
wants to do is detect three patterns which must not be inlined. Comment
the code, clean it up, and leave some hints about possible performance
improvements if this ever shows up on a profile.

Moving this off of the (now more expensive) inline cost analysis is
particularly important because we have to run this inliner even at -O0.

llvm-svn: 153814

interfaces. These methods were used in the old inline cost system where
there was a persistent cache that had to be updated, invalidated, and
cleared. We're now doing more direct computations that don't require
this intricate dance. Even if we resume some level of caching, it would
almost certainly have a simpler and more narrow interface than this.

llvm-svn: 153813

on a per-callsite walk of the called function's instructions, in
breadth-first order over the potentially reachable set of basic blocks.

This is a major shift in how inline cost analysis works to improve the
accuracy and rationality of inlining decisions. A brief outline of the
algorithm this moves to:

- Build a simplification mapping based on the callsite arguments to the
  function arguments.
- Push the entry block onto a worklist of potentially-live basic blocks.
- Pop the first block off of the *front* of the worklist (for
  breadth-first ordering) and walk its instructions using a custom
  InstVisitor.
- For each instruction's operands, re-map them based on the
  simplification mappings available for the given callsite.
- Compute any simplification possible of the instruction after
  re-mapping, and store that back int othe simplification mapping.
- Compute any bonuses, costs, or other impacts of the instruction on the
  cost metric.
- When the terminator is reached, replace any conditional value in the
  terminator with any simplifications from the mapping we have, and add
  any successors which are not proven to be dead from these
  simplifications to the worklist.
- Pop the next block off of the front of the worklist, and repeat.
- As soon as the cost of inlining exceeds the threshold for the
  callsite, stop analyzing the function in order to bound cost.

The primary goal of this algorithm is to perfectly handle dead code
paths. We do not want any code in trivially dead code paths to impact
inlining decisions. The previous metric was *extremely* flawed here, and
would always subtract the average cost of two successors of
a conditional branch when it was proven to become an unconditional
branch at the callsite. There was no handling of wildly different costs
between the two successors, which would cause inlining when the path
actually taken was too large, and no inlining when the path actually
taken was trivially simple. There was also no handling of the code
*path*, only the immediate successors. These problems vanish completely
now. See the added regression tests for the shiny new features -- we
skip recursive function calls, SROA-killing instructions, and high cost
complex CFG structures when dead at the callsite being analyzed.

Switching to this algorithm required refactoring the inline cost
interface to accept the actual threshold rather than simply returning
a single cost. The resulting interface is pretty bad, and I'm planning
to do lots of interface cleanup after this patch.

Several other refactorings fell out of this, but I've tried to minimize
them for this patch. =/ There is still more cleanup that can be done
here. Please point out anything that you see in review.

I've worked really hard to try to mirror at least the spirit of all of
the previous heuristics in the new model. It's not clear that they are
all correct any more, but I wanted to minimize the change in this single
patch, it's already a bit ridiculous. One heuristic that is *not* yet
mirrored is to allow inlining of functions with a dynamic alloca *if*
the caller has a dynamic alloca. I will add this back, but I think the
most reasonable way requires changes to the inliner itself rather than
just the cost metric, and so I've deferred this for a subsequent patch.
The test case is XFAIL-ed until then.

As mentioned in the review mail, this seems to make Clang run about 1%
to 2% faster in -O0, but makes its binary size grow by just under 4%.
I've looked into the 4% growth, and it can be fixed, but requires
changes to other parts of the inliner.

llvm-svn: 153812

visitor will now visit a CallInst and an InvokeInst with
instruction-specific visitors, then visit a generic CallSite visitor,
then delegate back to the Instruction visitor and the TerminatorInst
visitors depending on whether a call or an invoke originally. This will
be used in the soon-to-land inline cost rewrite.

llvm-svn: 153811

llvm-svn: 153810

llvm-svn: 153809

llvm-svn: 153808

llvm-svn: 153807

Internalize: Remove reference of @llvm.noinline, it was replaced with the noinline attribute a long time ago.

llvm-svn: 153806

llvm-svn: 153805

llvm-svn: 153804

llvm-svn: 153803

llvm-svn: 153802

one point, and I forgot to go back and clean it up. Sorry about that. =/

llvm-svn: 153801