The aim in this patch is to reduce work that VirtRegRewriter needs to do when
telling MachineRegisterInfo which physregs are in use. Up until now
VirtRegRewriter::rewrite has been doing rewriting and populating def info and
then proceeding to set whether a physreg is used based this info for every
physreg that the target provides. This can be expensive when a target has an
unusually high number of supported physregs, and is a noticeable chunk of
compile time for small programs on such targets.

So to reduce compile time, this patch simply adds the use of a SparseSet to the
rewrite function that is used to flag each physreg that is encountered in a
MachineFunction. Afterward, rather than iterating over the set of all physregs
for a given target to set the physregs used in MachineRegisterInfo, the new way
is to iterate over the set of physregs that were actually encountered and set
in the SparseSet. This improves compile time because the existing rewrite
function was iterating over all MachineOperands already, and because the
iterations afterward to setPhysRegUsed is reduced by use of the SparseSet data.

llvm-svn: 200919

I believe VZEXT_MOVL means "zero all vector elements except the first" (and
should have identical input & output types) whereas VZEXT means "zero extend
each element of a vector (discarding higher elements if necessary)".

For example:
    (v4i32 (vzext (v16i8 ...)))

should zero extend the low 4 bytes of the incoming vector to 32-bits,
discarding higher bytes.

However, somewhere in the past, these two concepts had become confused, even
leading to a nonsensical VSEXT_MOVL.

This re-merges the nodes where appropriate (all VSEXT_MOVL -> VSEXT, VZEXT_MOVL
-> VZEXT when it's an actual extension).

rdar://problem/15981990

llvm-svn: 200918

programs on targets with large register files. The root of the compile time
overhead was in the use of llvm::SmallVector to hold PhysRegEntries, which
resulted in slow-down from calling llvm::SmallVector::assign(N, 0). In contrast
std::vector uses the faster __platform_bzero to zero out primitive buffers when
assign is called, while SmallVector uses an iterator.

The fix for this was simply to replace the SmallVector with a dynamically
allocated buffer and to initialize or reinitialize the buffer based on the
total registers that the target architecture requires. The changes support
cases where a pass manager may be reused for different targets, and note that
the PhysRegEntries is allocated using calloc mainly for good for, and also to
quite tools like Valgrind (see comments for more info on this).

There is an rdar to track the fact that SmallVector doesn't have platform
specific speedup optimizations inside of it for things like this, and I'll
create a bugzilla entry at some point soon as well.

TL;DR: This fix replaces the expensive llvm::SmallVector<unsigned
char>::assign(N, 0) with a call to calloc for N bytes which is much faster
because SmallVector's assign uses iterators.

llvm-svn: 200917

we don't use assembly files

llvm-svn: 200916

llvm-svn: 200915

llvm-svn: 200914

large register files. The omission of Queries.clear() is perfectly safe because
LiveIntervalUnion::Query doesn't contain any data that needs freeing and
because LiveRegMatrix::runOnFunction happens to reset the OwningArrayPtr
holding Queries every time it is run, so there's no need to zero out the
queries either. Not having to do this for very large numbers of physregs
is a noticeable constant cost reduction in compilation of small programs.

llvm-svn: 200913

llvm-svn: 200911

llvm-svn: 200910

clang/test/FixIt/fixit-unicode-with-utf8-output.c has begun complained since LLVM r200885.
Although it is changes for StringRef, it brought LLVM_ON_WIN32 to Support/Locale.cpp.

Before r200885, LLVM_ON_WIN32 was undefined in Locale.cpp!

FIXME: We should consider i18n on win32.
llvm-svn: 200909

[asan] introduce two functions that will allow implementations of C++ garbage colection to work with asan's fake stack

llvm-svn: 200908

llvm-svn: 200907

llvm-svn: 200906

build but spectacularly changed behavior of the C++98 build. =]

This shows my one problem with not having unittests -- basic API
expectations aren't well exercised by the integration tests because they
*happen* to not come up, even though they might later. I'll probably add
a basic unittest to complement the integration testing later, but
I wanted to revive the bots.

llvm-svn: 200905

Fix PR17221 - can't catch virtual base classes when throwing derived NULL pointers. Specifically, libc++abi would crash when you tried it.

llvm-svn: 200904

The primary motivation for this pass is to separate the call graph
analysis used by the new pass manager's CGSCC pass management from the
existing call graph analysis pass. That analysis pass is (somewhat
unfortunately) over-constrained by the existing CallGraphSCCPassManager
requirements. Those requirements make it *really* hard to cleanly layer
the needed functionality for the new pass manager on top of the existing
analysis.

However, there are also a bunch of things that the pass manager would
specifically benefit from doing differently from the existing call graph
analysis, and this new implementation tries to address several of them:

- Be lazy about scanning function definitions. The existing pass eagerly
  scans the entire module to build the initial graph. This new pass is
  significantly more lazy, and I plan to push this even further to
  maximize locality during CGSCC walks.
- Don't use a single synthetic node to partition functions with an
  indirect call from functions whose address is taken. This node creates
  a huge choke-point which would preclude good parallelization across
  the fanout of the SCC graph when we got to the point of looking at
  such changes to LLVM.
- Use a memory dense and lightweight representation of the call graph
  rather than value handles and tracking call instructions. This will
  require explicit update calls instead of some updates working
  transparently, but should end up being significantly more efficient.
  The explicit update calls ended up being needed in many cases for the
  existing call graph so we don't really lose anything.
- Doesn't explicitly model SCCs and thus doesn't provide an "identity"
  for an SCC which is stable across updates. This is essential for the
  new pass manager to work correctly.
- Only form the graph necessary for traversing all of the functions in
  an SCC friendly order. This is a much simpler graph structure and
  should be more memory dense. It does limit the ways in which it is
  appropriate to use this analysis. I wish I had a better name than
  "call graph". I've commented extensively this aspect.

This is still very much a WIP, in fact it is really just the initial
bits. But it is about the fourth version of the initial bits that I've
implemented with each of the others running into really frustrating
problms. This looks like it will actually work and I'd like to split the
actual complexity across commits for the sake of my reviewers. =] The
rest of the implementation along with lots of wiring will follow
somewhat more rapidly now that there is a good path forward.

Naturally, this doesn't impact any of the existing optimizer. This code
is specific to the new pass manager.

A bunch of thanks are deserved for the various folks that have helped
with the design of this, especially Nick Lewycky who actually sat with
me to go through the fundamentals of the final version here.

llvm-svn: 200903

in my next patch. Sorry for the breakage.

llvm-svn: 200902

necessary until we add analyses to the driver, but I have such an
analysis ready and wanted to split this out. This is actually exercised
by the existing tests of the new pass manager as the analysis managers
are cross-checked and validated by the function and module managers.

llvm-svn: 200901

During DAGCombine visitShiftByConstant assumes that certain binary operations
with only constant operands can always be folded successfully. This is no longer
true when the constant is opaque. This commit fixes visitShiftByConstant by not
performing the optimization for opaque constants. Otherwise we would end up in
an infinite DAGCombine loop.

llvm-svn: 200900

In the following code:

    struct A { static const int sz; };
    template<class T> void f() { T arr[A::sz]; }

the array 'arr' is represented as a variable size array in the template.
If 'A::sz' gets value below in the translation unit, the array in
instantiation can turn into constant size array.

This change fixes PR18633.

Differential Revision: http://llvm-reviews.chandlerc.com/D2688

llvm-svn: 200899

225 is the default value of inline-threshold. This change will make sure
we have the same inlining behavior as prior to r200886.

As Chandler points out, even though we don't have code in our testing
suite that uses cold attribute, there are larger applications that do
use cold attribute.

r200886 + this commit intend to keep the same behavior as prior to r200886.
We can later on tune the inlinecold-threshold.

The main purpose of r200886 is to help performance of instrumentation based
PGO before we actually hook up inliner with analysis passes such as BPI and BFI.
For instrumentation based PGO, we try to increase inlining of hot functions and
reduce inlining of cold functions by setting inlinecold-threshold.

Another option suggested by Chandler is to use a boolean flag that controls
if we should use OptSizeThreshold for cold functions. The default value
of the boolean flag should not change the current behavior. But it gives us
less freedom in controlling inlining of cold functions.

llvm-svn: 200898

using-declaration, and they declare the same function (either because
the using-declaration is in the same namespace as the declaration it
imports, or because they're both extern "C"), they do not conflict.

llvm-svn: 200897

the << and >> bitwise operators.

rdar://15975725

llvm-svn: 200896

It is only used in MachObjectWriter.cpp. Another leftover from early days
of ELF in MC.

llvm-svn: 200895

This is a nop. doesSectionRequireSymbols is only used from
isSymbolLinkerVisible. isSymbolLinkerVisible only use from ELF was in

if (!Asm.isSymbolLinkerVisible(Symbol) && !Symbol.isUndefined())
  return false;

if (Symbol.isTemporary())
  return false;

If the symbol is a temporary this code returns false and it is irrelevant if
we take the first if or not. If the symbol is not a temporary,
Asm.isSymbolLinkerVisible returns true without ever calling
doesSectionRequireSymbols.

This was an horrible leftover from when support for ELF was first added.

llvm-svn: 200894

llvm-svn: 200893

Ideally only those transform passes that run at -O0 remain enabled,
in reality we get as close as we reasonably can.
Passes are responsible for disabling themselves, it's not the job of
the pass manager to do it for them.

llvm-svn: 200892

llvm-svn: 200891

llvm-svn: 200890

has a more precise type.

llvm-svn: 200889

llvm-svn: 200888

On R600, some address spaces have more strict alignment
requirements than others.

llvm-svn: 200887

Added command line option inlinecold-threshold to set threshold for inlining
functions with cold attribute. Listen to the cold attribute when it would
decrease the inline threshold.

llvm-svn: 200886

Now to copy a string into a BumpPtrAllocator and get a StringRef to the copy:

   StringRef myCopy = myStr.copy(myAllocator);
   

llvm-svn: 200885

This option will:
- load the given pch file
- verify it is not out of date by stat'ing dependencies, and
- return 0 on success and non-zero on error

llvm-svn: 200884

find a register.

The idea is to choose a color for the variable that cannot be allocated and
recolor its interferences around. Unlike the current register allocation scheme,
it is allowed to change the color of an already assigned (but maybe not
splittable or spillable) live interval while propagating this change to its
neighbors.
In other word, there are two things that may help finding an available color:
- Already assigned variables (RS_Done) can be recolored to different color.
- The recoloring allows to catch solutions that needs to touch more that just
  the neighbors of the current allocated variable.

E.g.,
vA can use {R1, R2    }
vB can use {    R2, R3}
vC can use {R1        }
Where vA, vB, and vC cannot be split anymore (they are reloads for instance) and
they all interfere.

vA is assigned R1
vB is assigned R2
vC tries to evict vA but vA is already done.
=> Regular register allocation heuristic fails.

Last chance recoloring kicks in:
vC does as if vA was evicted => vC uses R1.
vC is marked as fixed.
vA needs to find a color.
None are available.
vA cannot evict vC: vC is a fixed virtual register now.
vA does as if vB was evicted => vA uses R2.
vB needs to find a color.
R3 is available.
Recoloring => vC = R1, vA = R2, vB = R3.

<rdar://problem/15947839>

llvm-svn: 200883

We now properly detect when a result object has an immediate output stream and don't echo the results a second time.

<rdar://problem/15954906>

llvm-svn: 200882

I think this was just over-eagerness on my part. The analysis results
need to often be non-const because they need to (in some cases at least)
be updated by the transformation pass in order to remain correct. It
also makes lazy analyses (a common case) needlessly annoying to write in
order to make their entire state mutable.

llvm-svn: 200881

llvm-svn: 200880

An example summary provider for PyObject and the LLDB wrapper PythonObject hierarchy - this would have probably helped track down those refcount bugs..

llvm-svn: 200879