Commit Graph

5000 Commits

Author SHA1 Message Date
Juergen Ributzka
9bc1b73c9e Add C API for thread yielding callback.
Sometimes a LLVM compilation may take more time then a client would like to
wait for. The problem is that it is not possible to safely suspend the LLVM
thread from the outside. When the timing is bad it might be possible that the
LLVM thread holds a global mutex and this would block any progress in any other
thread.

This commit adds a new yield callback function that can be registered with a
context. LLVM will try to yield by calling this callback function, but there is
no guaranteed frequency. LLVM will only do so if it can guarantee that
suspending the thread won't block any forward progress in other LLVM contexts
in the same process.

Once the client receives the call back it can suspend the thread safely and
resume it at another time.

Related to <rdar://problem/16728690>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208945 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 02:33:15 +00:00
Jay Foad
b7ba5c2e2e Instead of littering asserts throughout the code after every call to
computeKnownBits, consolidate them into one assert at the end of
computeKnownBits itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208876 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-15 12:12:55 +00:00
Chandler Carruth
ca323cf916 Teach the constant folder to look through bitcast constant expressions
much more effectively when trying to constant fold a load of a constant.
Previously, we only handled bitcasts by trying to find a totally generic
byte representation of the constant and use that. Now, we look through
the bitcast to see what constant we might fold the load into, and then
try to form a constant expression cast of the found value that would be
equivalent to loading the value.

You might wonder why on earth this actually matters. Well, turns out
that the Itanium ABI causes us to create a single array for a vtable
where the first elements are virtual base offsets, followed by the
virtual function pointers. Because the array is homogenous the element
type is consistently i8* and we inttoptr the virtual base offsets into
the initial elements.

Then constructors bitcast these pointers to i64 pointers prior to
loading them. Boom, no more constant folding of virtual base offsets.
This is the first fix to LLVM to address the *insane* performance Eric
Niebler discovered with Clang on his range comprehensions[1]. There is
more to come though, this doesn't *really* fix the problem fully.

[1]: http://ericniebler.com/2014/04/27/range-comprehensions/

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208856 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-15 09:56:28 +00:00
Alp Toker
727273b11c Fix typos
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208839 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-15 01:52:21 +00:00
Jay Foad
6b543713a2 Rename ComputeMaskedBits to computeKnownBits. "Masked" has been
inappropriate since it lost its Mask parameter in r154011.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208811 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-14 21:14:37 +00:00
David Majnemer
cd237ed585 InstSimplify: Optimize signed icmp of -(zext V)
Summary:
We know that -(zext V) will always be <= zero, simplify signed icmps
that have these.

Uncovered using http://www.cs.utah.edu/~regehr/souper/

Reviewers: nicholas

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3754

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208809 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-14 20:16:28 +00:00
Jay Foad
5fa4d1cd1a Update the comments for ComputeMaskedBits, which lost its Mask parameter
in r154011.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208757 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-14 08:00:07 +00:00
Sebastian Pop
d2b27bba87 use nullptr instead of NULL
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208622 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-12 20:11:01 +00:00
Sebastian Pop
2f5f1c2ccb do not assert when delinearization fails
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208615 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-12 19:01:53 +00:00
Sebastian Pop
d9673ebd34 use isZero()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208614 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-12 19:01:49 +00:00
Benjamin Kramer
bfd5dad4c9 SCEV: Use range-based for loop and fold variable into assert.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208476 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-10 17:47:18 +00:00
Sebastian Pop
754e940865 move findArrayDimensions to ScalarEvolution
we do not use the information from SCEVAddRecExpr to compute the shape of the array,
so a better place for this function is in ScalarEvolution.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208456 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-09 22:45:07 +00:00
Sebastian Pop
f255eb9643 fix typo in debug message
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208455 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-09 22:45:02 +00:00
Tobias Grosser
24ac5dfba0 Correct formatting.
Sorry for the commit spam. My clang-format crashed on me and the vim
plugin did not print an error, but instead just left the formatting
untouched.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208358 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-08 21:43:19 +00:00
Tobias Grosser
3a722581b9 Use std::remove_if to remove elements from a vector
Suggested-by: Benjamin Kramer <benny.kra@gmail.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208357 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-08 21:32:59 +00:00
Rafael Espindola
2413bf3004 Use a range loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208343 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-08 17:57:50 +00:00
Tobias Grosser
f46646d87b Revert "SCEV: Use I = vector<>.erase(I) to iterate and delete at the same time"
as committed in r208282. The original commit was incorrect.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208286 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-08 07:55:34 +00:00
Tobias Grosser
96f8c5651c SCEV: Use I = vector<>.erase(I) to iterate and delete at the same time
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208282 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-08 07:12:44 +00:00
Sebastian Pop
4842e7db63 avoid segfaulting
*Quotient and *Remainder don't have to be initialized.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208238 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-07 19:00:37 +00:00
Sebastian Pop
bde4574fcb do not collect undef terms
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208237 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-07 19:00:32 +00:00
Sebastian Pop
5026b2cc8b split delinearization pass in 3 steps
To compute the dimensions of the array in a unique way, we split the
delinearization analysis in three steps:

- find parametric terms in all memory access functions
- compute the array dimensions from the set of terms
- compute the delinearized access functions for each dimension

The first step is executed on all the memory access functions such that we
gather all the patterns in which an array is accessed. The second step reduces
all this information in a unique description of the sizes of the array. The
third step is delinearizing each memory access function following the common
description of the shape of the array computed in step 2.

This rewrite of the delinearization pass also solves a problem we had with the
previous implementation: because the previous algorithm was by induction on the
structure of the SCEV, it would not correctly recognize the shape of the array
when the memory access was not following the nesting of the loops: for example,
see polly/test/ScopInfo/multidim_only_ivs_3d_reverse.ll

; void foo(long n, long m, long o, double A[n][m][o]) {
;
;   for (long i = 0; i < n; i++)
;     for (long j = 0; j < m; j++)
;       for (long k = 0; k < o; k++)
;         A[i][k][j] = 1.0;

Starting with this patch we no longer delinearize access functions that do not
contain parameters, for example in test/Analysis/DependenceAnalysis/GCD.ll

;;  for (long int i = 0; i < 100; i++)
;;    for (long int j = 0; j < 100; j++) {
;;      A[2*i - 4*j] = i;
;;      *B++ = A[6*i + 8*j];

these accesses will not be delinearized as the upper bound of the loops are
constants, and their access functions do not contain SCEVUnknown parameters.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208232 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-07 18:01:20 +00:00
Tobias Grosser
a1f8bd6753 [C++11] Add NArySCEV->Operands iterator range
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208158 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-07 06:07:47 +00:00
Duncan P. N. Exon Smith
cca77fc0d6 blockfreq: Move include to .cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208035 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-06 01:57:42 +00:00
Chandler Carruth
febf86d7e3 [LCG] Add the last (and most complex) of the edge insertion mutation
operations on the call graph. This one forms a cycle, and while not as
complex as removing an internal edge from an SCC, it involves
a reasonable amount of work to find all of the nodes newly connected in
a cycle.

Also somewhat alarming is the worst case complexity here: it might have
to walk roughly the entire SCC inverse DAG to insert a single edge. This
is carefully documented in the API (I hope).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207935 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-04 09:38:32 +00:00
Juergen Ributzka
b2bd7e89e6 [TBAA] Fix handling of mixed TBAA (path-aware and non-path-aware TBAA).
This fix simply ensures that both metadata nodes are path-aware before
performing path-aware alias analysis.

This issue isn't normally triggered in LLVM, because we perform an autoupgrade
of the TBAA metadata to the new format when reading in LL or BC files. This
issue only appears when a client creates the IR manually and mixes old and new
TBAA metadata format.

This fixes <rdar://problem/16760860>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207923 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-03 22:32:52 +00:00
Chandler Carruth
3ce8291da3 [LCG] Add the other simple edge insertion API to the call graph. This
just connects an SCC to one of its descendants directly. Not much of an
impact. The last one is the hard one -- connecting an SCC to one of its
ancestors, and thereby forming a cycle such that we have to merge all
the SCCs participating in the cycle.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207751 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-01 12:18:20 +00:00
Chandler Carruth
54bf6fd4a5 [LCG] Don't lookup the child SCC twice. Spotted this by inspection, and
no functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207750 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-01 12:16:31 +00:00
Chandler Carruth
b8f462501b [LCG] Add some basic methods for querying the parent/child relationships
of SCCs in the SCC DAG. Exercise them in the big graph test case. These
will be especially useful for establishing invariants in insertion
logic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207749 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-01 12:12:42 +00:00
Chandler Carruth
491f476b8b [LCG] Add the really, *really* boring edge insertion case: adding an
edge entirely within an existing SCC. Shockingly, making the connected
component more connected is ... a total snooze fest. =]

Anyways, its wired up, and I even added a test case to make sure it
pretty much sorta works. =D

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207631 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-30 10:48:36 +00:00
Chandler Carruth
6253c04fc9 [LCG] Actually test the *basic* edge removal bits (IE, the non-SCC
bits), and discover that it's totally broken. Yay tests. Boo bug. Fix
the basic edge removal so that it works by nulling out the removed edges
rather than actually removing them. This leaves the indices valid in the
map from callee to index, and preserves some of the locality for
iterating over edges. The iterator is made bidirectional to reflect that
it now has to skip over null entries, and the skipping logic is layered
onto it.

As future work, I would like to track essentially the "load factor" of
the edge list, and when it falls below a threshold do a compaction.

An alternative I considered (and continue to consider) is storing the
callees in a doubly linked list where each element of the list is in
a set (which is essentially the classical linked-hash-table
datastructure). The problem with that approach is that either you need
to heap allocate the linked list nodes and use pointers to them, or use
a bucket hash table (with even *more* linked list pointer overhead!),
etc. It's pretty easy to get 5x overhead for values that are just
pointers. So far, I think punching holes in the vector, and periodic
compaction is likely to be much more efficient overall in the space/time
tradeoff.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207619 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-30 07:45:27 +00:00
Benjamin Kramer
7259f14839 raw_ostream: Forward declare OpenFlags and include FileSystem.h only where necessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207593 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 23:26:49 +00:00
Duncan P. N. Exon Smith
6919443535 blockfreq: Defer to BranchProbability::scale()
`BlockMass` can now defer to `BranchProbability::scale()`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207547 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 16:20:05 +00:00
Duncan P. N. Exon Smith
744d1555fa blockfreq: Remove more extra typenames from r207438
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207440 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-28 20:22:29 +00:00
Duncan P. N. Exon Smith
96837f7232 Reapply "blockfreq: Approximate irreducible control flow"
This reverts commit r207287, reapplying r207286.

I'm hoping that declaring an explicit struct and instantiating
`addBlockEdges()` directly works around the GCC crash from r207286.
This is a lot more boilerplate, though.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207438 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-28 20:02:29 +00:00
Chandler Carruth
db0b52c8e0 [LCG] Add the most basic of edge insertion to the lazy call graph. This
just handles the pre-DFS case. Also add some test cases for this case to
make sure it works.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207411 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-28 11:10:23 +00:00
Chandler Carruth
e52aad4202 [LCG] Make the return of the IntraSCC removal method actually match its
contract (and be much more useful). It now provides exactly the
post-order traversal a caller might need to perform on newly formed
SCCs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207410 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-28 10:49:06 +00:00
Chandler Carruth
d6d57bc3fb [inliner] Significantly improve the compile time in cases like PR19499
by avoiding inlining massive switches merely because they have no
instructions in them. These switches still show up where we fail to form
lookup tables, and in those cases they are actually going to cause
a very significant code size hit anyways, so inlining them is not the
right call. The right way to fix any performance regressions stemming
from this is to enhance the switch-to-lookup-table logic to fire in more
places.

This makes PR19499 about 5x less bad. It uncovers a second compile time
problem in that test case that is unrelated (surprisingly!).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207403 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-28 08:52:44 +00:00
Craig Topper
c34a25d59d [C++] Use 'nullptr'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207394 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-28 04:05:08 +00:00
Chandler Carruth
e3a8e534e1 [LCG] Re-organize the methods for mutating a call graph to make their
API requirements much more obvious.

The key here is that there are two totally different use cases for
mutating the graph. Prior to doing any SCC formation, it is very easy to
mutate the graph. There may be users that want to do small tweaks here,
and then use the already-built graph for their SCC-based operations.
This method remains on the graph itself and is documented carefully as
being cheap but unavailable once SCCs are formed.

Once SCCs are formed, and there is some in-flight DFS building them, we
have to be much more careful in how we mutate the graph. These mutation
operations are sunk onto the SCCs themselves, which both simplifies
things (the code was already there!) and helps make it obvious that
these interfaces are only applicable within that context. The other
primary constraint is that the edge being mutated is actually related to
the SCC on which we call the method. This helps make it obvious that you
cannot arbitrarily mutate some other SCC.

I've tried to write much more complete documentation for the interesting
mutation API -- intra-SCC edge removal. Currently one aspect of this
documentation is a lie (the result list of SCCs) but we also don't even
have tests for that API. =[ I'm going to add tests and fix it to match
the documentation next.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207339 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-27 01:59:50 +00:00
Chandler Carruth
9a1fab37c7 [LCG] Rather than removing nodes from the SCC entry set when we process
them, just skip over any DFS-numbered nodes when finding the next root
of a DFS. This allows the entry set to just be a vector as we populate
it from a uniqued source. It also removes the possibility for a linear
scan of the entry set to actually do the removal which can make things
go quadratic if we get unlucky.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207312 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-26 09:45:55 +00:00
Chandler Carruth
797bbced53 [LCG] Rotate the full SCC finding algorithm to avoid round-trips through
the DFS stack for leaves in the call graph. As mentioned in my previous
commit, this is particularly interesting for graphs which have high fan
out but low connectivity resulting in many leaves. For such graphs, this
can remove a large % of the DFS stack traffic even though it doesn't
make the stack much smaller.

It's a bit easier to formulate this for the full algorithm because that
one stops completely for each SCC. For example, I was able to directly
eliminate the "Recurse" boolean used to continue an outer loop from the
inner loop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207311 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-26 09:28:00 +00:00
Chandler Carruth
8495669112 [LCG] Hoist the main DFS loop out of the edge removal function. This
makes working through the worklist much cleaner, and makes it possible
to avoid the 'bool-to-continue-the-outer-loop' hack. Not a huge
difference, but I think this is approaching as polished as I can make
it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207310 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-26 09:06:53 +00:00
Chandler Carruth
dec9a2ca23 [LCG] In the incremental SCC re-formation, lift the node currently being
processed in the DFS out of the stack completely. Keep it exclusively in
a variable. Re-shuffle some code structure to make this easier. This can
have a very dramatic effect in some cases because call graphs tend to
look like a high fan-out spanning tree. As a consequence, there are
a large number of leaf nodes in the graph, and this technique causes
leaf nodes to never even go into the stack. While this only reduces the
max depth by 1, it may cause the total number of round trips through the
stack to drop by a lot.

Now, most of this isn't really relevant for the incremental version. =]
But I wanted to prototype it first here as this variant is in ways more
complex. As long as I can get the code factored well here, I'll next
make the primary walk look the same. There are several refactorings this
exposes I think.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207306 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-26 03:36:42 +00:00
Chandler Carruth
0c8f0bfce2 [LCG] Special case the removal of self edges. These don't impact the SCC
graph in any way because we don't track edges in the SCC graph, just
nodes. This also lets us add a nice assert about the invariant that
we're working on at least a certain number of nodes within the SCC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207305 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-26 03:36:37 +00:00
Chandler Carruth
64e1be4bf1 [LCG] Refactor the duplicated code I added in my last commit here into
a helper function. Also factor the other two places where we did the
same thing into the helper function. =] Much cleaner this way. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207300 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-26 01:03:46 +00:00
Duncan P. N. Exon Smith
cee7abfb2c Revert "blockfreq: Approximate irreducible control flow"
This reverts commit r207286.  It causes an ICE on the
cmake-llvm-x86_64-linux buildbot [1]:

    llvm/lib/Analysis/BlockFrequencyInfo.cpp: In lambda function:
    llvm/lib/Analysis/BlockFrequencyInfo.cpp:182:1: internal compiler error: in get_expr_operands, at tree-ssa-operands.c:1035

[1]: http://bb.pgr.jp/builders/cmake-llvm-x86_64-linux/builds/12093/steps/build_llvm/logs/stdio

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207287 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 23:16:58 +00:00
Duncan P. N. Exon Smith
d905bba691 blockfreq: Approximate irreducible control flow
Previously, irreducible backedges were ignored.  With this commit,
irreducible SCCs are discovered on the fly, and modelled as loops with
multiple headers.

This approximation specifies the headers of irreducible sub-SCCs as its
entry blocks and all nodes that are targets of a backedge within it
(excluding backedges within true sub-loops).  Block frequency
calculations act as if we insert a new block that intercepts all the
edges to the headers.  All backedges and entries to the irreducible SCC
point to this imaginary block.  This imaginary block has an edge (with
even probability) to each header block.

The result is now reasonable enough that I've added a number of
testcases for irreducible control flow.  I've outlined in
`BlockFrequencyInfoImpl.h` ways to improve the approximation.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207286 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 23:08:57 +00:00
Duncan P. N. Exon Smith
2d18167483 blockfreq: Further shift logic to LoopData
Move a lot of the loop-related logic that was sprinkled around the code
into `LoopData`.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207258 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 18:47:04 +00:00
Duncan P. N. Exon Smith
db8c1ae04e SCC: Change clients to use const, NFC
It's fishy to be changing the `std::vector<>` owned by the iterator, and
no one actual does it, so I'm going to remove the ability in a
subsequent commit.  First, update the users.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207252 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 18:24:50 +00:00
Chandler Carruth
09d1d3d588 [LCG] During the incremental update of an SCC, switch to using the
SCCMap to test for nodes that have been re-added to the root SCC rather
than a set vector. We already have done the SCCMap lookup, we juts need
to test it in two different ways. In turn, do most of the processing of
these nodes as they go into the root SCC rather than lazily. This
simplifies the final loop to just stitch the root SCC into its
children's parent sets. No functionlatiy changed.

However, this makes a few things painfully obvious, which was my intent.
=] There is tons of repeated code introduced here and elsewhere. I'm
splitting the refactoring of that code into helpers from this change so
its clear that this is the change which switches the datastructures used
around, and the other is a pure factoring & deduplication of code
change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207217 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 09:52:44 +00:00
Chandler Carruth
7b7a21b192 [LCG] During the incremental re-build of an SCC after removing an edge,
remove the nodes in the SCC from the SCC map entirely prior to the DFS
walk. This allows the SCC map to represent both the state of
not-yet-re-added-to-an-SCC and added-back-to-this-SCC independently. The
first is being missing from the SCC map, the second is mapping back to
'this'. In a subsequent commit, I'm going to use this property to
simplify the new node list for this SCC.

In theory, I think this also makes the contract for orphaning a node
from the graph slightly less confusing. Now it is also orphaned from the
SCC graph. Still, this isn't quite right either, and so I'm not adding
test cases here. I'll add test cases for the behavior of orphaning nodes
when the code *actually* supports it. The change here is mostly
incidental, my goal is simplifying the algorithm.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207213 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 09:08:10 +00:00
Chandler Carruth
cea05a55a2 [LCG] Rather than doing a linear time SmallSetVector removal of each
child from the worklist, wait until we actually need to pop another
element off of the worklist and skip over any that were already visited
by the DFS. This also enables swapping the nodes of the SCC into the
worklist. No functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207212 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 09:08:05 +00:00
Chandler Carruth
6b168d6741 [LCG] Remove a completely unnecessary loop. It wasn't even doing any
thing, just mucking up the code. I feel bad that I even wrote this loop.
Very sorry. The diff is huge because of the indent change, but I promise
all this is doing is realizing that the outer two loops were actually
the exact same loops, and we didn't need two of them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207202 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 06:45:06 +00:00
Chandler Carruth
fe0f0187be [LCG] Now that the loop structure of the core SCC finding routine is
factored into a more reasonable form, replace the tail call with
a simple outer-loop continuation. It's sad that C++ makes this so
awkward to write, but it seems more direct and clear than the tail call
at this point.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207201 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 06:38:58 +00:00
Duncan P. N. Exon Smith
39087bfbf0 blockfreq: Only one mass distribution per node
Remove the concepts of "forward" and "general" mass distributions, which
was wrong.  The split might have made sense in an early version of the
algorithm, but it's definitely wrong now.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207195 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:43 +00:00
Duncan P. N. Exon Smith
9c9891431b blockfreq: Document assertion
<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207194 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:40 +00:00
Duncan P. N. Exon Smith
16df231a82 blockfreq: Document high-level functions
<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207191 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:32 +00:00
Duncan P. N. Exon Smith
58aa607205 blockfreq: Scale LoopData::Scale on the way down
Rather than scaling loop headers and then scaling all the loop members
by the header frequency, scale `LoopData::Scale` itself, and scale the
loop members by it.  It's much more obvious what's going on this way,
and doesn't cost any extra multiplies.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207189 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:27 +00:00
Duncan P. N. Exon Smith
f47649f7f9 blockfreq: unwrapLoopPackage() => unwrapLoop()
<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207188 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:25 +00:00
Duncan P. N. Exon Smith
ed306d0cf5 blockfreq: Pass the Loop directly into unwrapLoopPackage()
<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207187 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:23 +00:00
Duncan P. N. Exon Smith
e249a45b5b blockfreq: Unwrap from Loops
When unwrapping loops, just visit the loops rather than all nodes.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207186 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:20 +00:00
Duncan P. N. Exon Smith
3475765998 blockfreq: Separate unwrapLoops() from finalizeMetrics()
<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207185 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:17 +00:00
Duncan P. N. Exon Smith
7ed8c05157 blockfreq: Expose getPackagedNode()
Make `getPackagedNode()` a member function of
`BlockFrequencyInfoImplBase` so that it's available for templated code.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207183 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:12 +00:00
Duncan P. N. Exon Smith
3df8534be1 blockfreq: Store the header with the members
<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207182 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:09 +00:00
Duncan P. N. Exon Smith
7e26181f6b blockfreq: Encapsulate LoopData::Header
<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207181 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:06 +00:00
Duncan P. N. Exon Smith
336238cebe blockfreq: Use LoopData directly
Instead of passing around loop headers, pass around `LoopData` directly.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207179 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:38:01 +00:00
Duncan P. N. Exon Smith
6f1f9f4c7f blockfreq: Use a std::list for Loops
As pointed out by David Blaikie in code review, a `std::list<T>` is
simpler than a `std::vector<std::unique_ptr<T>>`.  Another option is a
`std::deque<T>` (which allocates in chunks), but I'd like to leave open
the option of inserting in the middle of the sequence for handling
irreducible control flow on the fly.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207177 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 04:30:06 +00:00
Chandler Carruth
2a25daa0a9 [LCG] Switch a weird do/while loop that actually couldn't fail its
condition into an obviously infinite loop with an assert about the
degenerate condition. No functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207147 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 21:19:30 +00:00
Chandler Carruth
befdb1a642 [LCG] Incorporate the core trick of improvements on the naive Tarjan's
algorithm here: http://dl.acm.org/citation.cfm?id=177301.

The idea of isolating the roots has even more relevance when using the
stack not just to implement the DFS but also to implement the recursive
step. Because we use it for the recursive step, to isolate the roots we
need to maintain two stacks: one for our recursive DFS walk, and another
of the nodes that have been walked. The nice thing is that the latter
will be half the size. It also fixes a complete hack where we scanned
backwards over the stack to find the next potential-root to continue
processing. Now that is always the top of the DFS stack.

While this is a really nice improvement already (IMO) it further opens
the door for two important simplifications:

1) De-duplicating some of the code across the two different walks. I've
   actually made the duplication a bit worse in some senses with this
   patch because the two are starting to converge.
2) Dramatically simplifying the loop structures of both walks.

I wanted to do those separately as they'll be essentially *just* CFG
restructuring. This patch on the other hand actually uses different
datastructures to implement the algorithm itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207098 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 11:05:20 +00:00
Chandler Carruth
6c7af1bde8 [LCG] Rotate logic applied to the top of the DFSStack to instead be
applied prior to pushing a node onto the DFSStack. This is the first
step toward avoiding the stack entirely for leaf nodes. It also
simplifies things a bit and I think is pointing the way toward factoring
some more of the shared logic out of the two implementations.

It is also making it more obvious how to restructure the loops
themselves to be a bit easier to read (although no different in terms of
functionality).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207095 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 09:59:59 +00:00
Chandler Carruth
bcb39a444b [LCG] Switch the parent SCC tracking from a SmallSetVector to
a SmallPtrSet. Currently, there is no need for stable iteration in this
dimension, and I now thing there won't need to be going forward.

If this is ever re-introduced in any form, it needs to not be
a SetVector based solution because removal cannot be linear. There will
be many SCCs with large numbers of parents. When encountering these, the
incremental SCC update for intra-SCC edge removal was quadratic due to
linear removal (kind of).

I'm really hoping we can avoid having an ordering property here at all
though...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207091 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 09:22:31 +00:00
Chandler Carruth
9e65c46345 [LCG] We don't actually need a set in each SCC to track the nodes. We
can use the node -> SCC mapping in the top-level graph to test this on
the rare occasions we need it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207090 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 08:55:36 +00:00
Craig Topper
e703fcb975 [C++] Use 'nullptr'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207083 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-24 06:44:33 +00:00
Chandler Carruth
9f2150c046 [LCG] Normalize the post-order SCC iterator to just iterate over the SCC
values rather than having pointers in weird places.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207053 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 23:51:07 +00:00
Chandler Carruth
306d5ba092 [LCG] Switch the primary node iterator to be a *much* more normal C++
iterator, returning a Node by reference on dereference.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207048 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 23:34:48 +00:00
Chandler Carruth
807c1bc847 [LCG] Make the insertion and query paths into the LCG which cannot fail
return references to better model this property.

No functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207047 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 23:20:36 +00:00
Chandler Carruth
31d2477c68 [LCG] Switch the SCC lookup to be in terms of call graph nodes rather
than functions. So far, this access pattern is *much* more common. It
seems likely that any user of this interface is going to have nodes at
the point that they are querying the SCCs.

No functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207045 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 23:12:06 +00:00
Chandler Carruth
88508669ff [LCG] Switch the primary SCC building code to use the negative low-link
values rather than an expensive dense map query to test whether children
have already been popped into an SCC. This matches the incremental SCC
building code. I've also included the assert that I put there but
updated both of their text.

No functionality changed here.

I still don't have any great ideas for sharing the code between the two
implementations, but I may try a brute-force approach to factoring it at
some point.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207042 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 22:28:13 +00:00
Chandler Carruth
e42618b4bc [LCG] Add the first round of mutation support to the lazy call graph.
This implements the core functionality necessary to remove an edge from
the call graph and correctly update both the basic graph and the SCC
structure. As part of that it has to run a tiny (in number of nodes)
Tarjan-style DFS walk of an SCC being mutated to compute newly formed
SCCs, etc.

This is *very rough* and a WIP. I have a bunch of FIXMEs for code
cleanup that will reduce the boilerplate in this change substantially.
I also have a bunch of simplifications to various parts of both
algorithms that I want to make, but first I'd like to have a more
holistic picture. Ideally, I'd also like more testing. I'll probably add
quite a few more unit tests as I go here to cover the various different
aspects and corner cases of removing edges from the graph.

Still, this is, so far, successfully updating the SCC graph in-place
without disrupting the identity established for the existing SCCs even
when we do challenging things like delete the critical edge that made an
SCC cycle at all and have to reform things as a tree of smaller SCCs.
Getting this to work is really critical for the new pass manager as it
is going to associate significant state with the SCC instance and needs
it to be stable. That is also the motivation behind the return of the
newly formed SCCs. Eventually, I'll wire this all the way up to the
public API so that the pass manager can use it to correctly re-enqueue
newly formed SCCs into a fresh postorder traversal.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206968 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 11:03:03 +00:00
Chandler Carruth
b9619110af [LCG] Implement Tarjan's algorithm correctly this time. We have to walk
up the stack finishing the exploration of each entries children before
we're finished in addition to accounting for their low-links. Added
a unittest that really hammers home the need for this with interlocking
cycles that would each appear distinct otherwise and crash or compute
the wrong result. As part of this, nuke a stale fixme and bring the rest
of the implementation still more closely in line with the original
algorithm.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206966 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 10:31:17 +00:00
Chandler Carruth
07c2241e45 [LCG] Add a unittest for the LazyCallGraph. I had a weak moment and
resisted this for too long. Just with the basic testing here I was able
to exercise the analysis in more detail and sift out both type signature
bugs in the API and a bug in the DFS numbering. All of these are fixed
here as well.

The unittests will be much more important for the mutation support where
it is necessary to craft minimal mutations and then inspect the state of
the graph. There is just no way to do that with a standard FileCheck
test. However, unittesting these kinds of analyses is really quite easy,
especially as they're designed with the new pass manager where there is
essentially no infrastructure required to rig up the core logic and
exercise it at an API level.

As a minor aside about the DFS numbering bug, the DFS numbering used in
LCG is a bit unusual. Rather than numbering from 0, we number from 1,
and use 0 as the sentinel "unvisited" state. Other implementations often
use '-1' for this, but I find it easier to deal with 0 and it shouldn't
make any real difference provided someone doesn't write silly bugs like
forgetting to actually initialize the DFS numbering. Oops. ;]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206954 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 08:08:49 +00:00
Chandler Carruth
b001573515 [LCG] Hoist the logic for forming a new SCC from the top of the DFSStack
into a helper function. I plan to re-use it for doing incremental
DFS-based updates to the SCCs when we mutate the call graph.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206948 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 06:09:03 +00:00
Chandler Carruth
b3112f6acc [LCG] Switch the Callee sets to be DenseMaps pointing to the index into
the Callee list. This is going to be quite important to prevent removal
from going quadratic. No functionality changed at this point, this is
one of the refactoring patches I've broken out of my initial work toward
mutation updates of the call graph.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206938 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-23 04:00:17 +00:00
Duncan P. N. Exon Smith
846a14340c blockfreq: Skip irreducible backedges inside functions
The branch that skips irreducible backedges was only active when
propagating mass at the top-level.  In particular, when propagating mass
through a loop recognized by `LoopInfo` with irreducible control flow
inside, irreducible backedges would not be skipped.

Not sure where that idea came from, but the result was that mass was
lost until after loop exit.  Added a testcase that covers this case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206860 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 03:31:53 +00:00
Duncan P. N. Exon Smith
dda2f883dd blockfreq: Rename PackagedLoops => Loops
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206859 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 03:31:50 +00:00
Duncan P. N. Exon Smith
40a483e980 blockfreq: Use a pointer for ContainingLoop too
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206858 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 03:31:44 +00:00
Duncan P. N. Exon Smith
92897fda32 blockfreq: Use pointers to loops instead of an index
Store pointers directly to loops inside the nodes.  This could have been
done without changing the type stored in `std::vector<>`.  However,
rather than computing the number of loops before constructing them
(which `LoopInfo` doesn't provide directly), I've switched to a
`vector<unique_ptr<LoopData>>`.

This adds some heap overhead, but the number of loops is typically
small.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206857 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 03:31:37 +00:00
Duncan P. N. Exon Smith
153a265d01 blockfreq: Implement clear() explicitly
This was implicitly with copy assignment before, which fails to actually
clear `std::vector<>`'s heap storage.  Move assignment would work, but
since MSVC can't imply those anyway, explicitly `clear()`-ing members
makes more sense.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206856 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 03:31:34 +00:00
Duncan P. N. Exon Smith
aa866b9ae7 blockfreq: Rename PackagedLoopData => LoopData
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206855 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 03:31:31 +00:00
Chandler Carruth
4da253756d [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all the header #include lines, lib/Analysis/...
edition.

This one has a bit extra as there were *other* #define's before #include
lines in addition to DEBUG_TYPE. I've sunk all of them as a block.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206843 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 02:48:03 +00:00
Chandler Carruth
8677f2ff9a [Modules] Remove potential ODR violations by sinking the DEBUG_TYPE
define below all header includes in the lib/CodeGen/... tree. While the
current modules implementation doesn't check for this kind of ODR
violation yet, it is likely to grow support for it in the future. It
also removes one layer of macro pollution across all the included
headers.

Other sub-trees will follow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206837 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 02:02:50 +00:00
Chandler Carruth
283b399377 [Modules] Make Support/Debug.h modular. This requires it to not change
behavior based on other files defining DEBUG_TYPE, which means it cannot
define DEBUG_TYPE at all. This is actually better IMO as it forces folks
to define relevant DEBUG_TYPEs for their files. However, it requires all
files that currently use DEBUG(...) to define a DEBUG_TYPE if they don't
already. I've updated all such files in LLVM and will do the same for
other upstream projects.

This still leaves one important change in how LLVM uses the DEBUG_TYPE
macro going forward: we need to only define the macro *after* header
files have been #include-ed. Previously, this wasn't possible because
Debug.h required the macro to be pre-defined. This commit removes that.
By defining DEBUG_TYPE after the includes two things are fixed:

- Header files that need to provide a DEBUG_TYPE for some inline code
  can do so by defining the macro before their inline code and undef-ing
  it afterward so the macro does not escape.

- We no longer have rampant ODR violations due to including headers with
  different DEBUG_TYPE definitions. This may be mostly an academic
  violation today, but with modules these types of violations are easy
  to check for and potentially very relevant.

Where necessary to suppor headers with DEBUG_TYPE, I have moved the
definitions below the includes in this commit. I plan to move the rest
of the DEBUG_TYPE macros in LLVM in subsequent commits; this one is big
enough.

The comments in Debug.h, which were hilariously out of date already,
have been updated to reflect the recommended practice going forward.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206822 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 22:55:11 +00:00
Duncan P. N. Exon Smith
9c3ac928df blockfreq: Some cleanup of UnsignedFloat
Change `PositiveFloat` to `UnsignedFloat`, and fix some of the comments
to indicate that it's disappearing eventually.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206771 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 18:31:58 +00:00
Duncan P. N. Exon Smith
9a11d668f9 Reapply "blockfreq: Rewrite BlockFrequencyInfoImpl"
This reverts commit r206707, reapplying r206704.  The preceding commit
to CalcSpillWeights should have sorted out the failing buildbots.

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206766 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 17:57:07 +00:00
Chandler Carruth
57418d8f54 [PM] Add a new-PM-style CGSCC pass manager using the newly added
LazyCallGraph analysis framework. Wire it up all the way through the opt
driver and add some very basic testing that we can build pass pipelines
including these components. Still a lot more to do in terms of testing
that all of this works, but the basic pieces are here.

There is a *lot* of boiler plate here. It's something I'm going to
actively look at reducing, but I don't have any immediate ideas that
don't end up making the code terribly complex in order to fold away the
boilerplate. Until I figure out something to minimize the boilerplate,
almost all of this is based on the code for the existing pass managers,
copied and heavily adjusted to suit the needs of the CGSCC pass
management layer.

The actual CG management still has a bunch of FIXMEs in it. Notably, we
don't do *any* updating of the CG as it is potentially invalidated.
I wanted to get this in place to motivate the new analysis, and add
update APIs to the analysis and the pass management layers in concert to
make sure that the *right* APIs are present.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206745 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 11:12:00 +00:00
Chandler Carruth
29e0c0b57c [LCG] Add some basic debug output to the LCG pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206730 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-21 05:04:24 +00:00
Duncan P. N. Exon Smith
f44eda4764 Revert "blockfreq: Rewrite BlockFrequencyInfoImpl"
This reverts commit r206704, as expected.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206707 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-19 22:46:00 +00:00
Duncan P. N. Exon Smith
f465370a49 Reapply "blockfreq: Rewrite BlockFrequencyInfoImpl"
This reverts commit r206677, reapplying my BlockFrequencyInfo rewrite.

I've done a careful audit, added some asserts, and fixed a couple of
bugs (unfortunately, they were in unlikely code paths).  There's a small
chance that this will appease the failing bots [1][2].  (If so, great!)

If not, I have a follow-up commit ready that will temporarily add
-debug-only=block-freq to the two failing tests, allowing me to compare
the code path between what the failing bots and what my machines (and
the rest of the bots) are doing.  Once I've triggered those builds, I'll
revert both commits so the bots go green again.

[1]: http://bb.pgr.jp/builders/ninja-x64-msvc-RA-centos6/builds/1816
[2]: http://llvm-amd64.freebsd.your.org/b/builders/clang-i386-freebsd/builds/18445

<rdar://problem/14292693>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206704 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-19 22:34:26 +00:00
Duncan P. N. Exon Smith
2033057de8 Revert "blockfreq: Rewrite BlockFrequencyInfoImpl" (#2)
This reverts commit r206666, as planned.

Still stumped on why the bots are failing.  Sanitizer bots haven't
turned anything up.  If anyone can help me debug either of the failures
(referenced in r206666) I'll owe them a beer.  (In the meantime, I'll be
auditing my patch for undefined behaviour.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206677 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-19 00:42:46 +00:00
Duncan P. N. Exon Smith
036e26bc29 Reapply "blockfreq: Rewrite BlockFrequencyInfoImpl" (#2)
This reverts commit r206628, reapplying r206622 (and r206626).

Two tests are failing only on buildbots [1][2]: i.e., I can't reproduce
on Darwin, and Chandler can't reproduce on Linux.  Asan and valgrind
don't tell us anything, but we're hoping the msan bot will catch it.

So, I'm applying this again to get more feedback from the bots.  I'll
leave it in long enough to trigger builds in at least the sanitizer
buildbots (it was failing for reasons unrelated to my commit last time
it was in), and hopefully a few others.... and then I expect to revert a
third time.

[1]: http://bb.pgr.jp/builders/ninja-x64-msvc-RA-centos6/builds/1816
[2]: http://llvm-amd64.freebsd.your.org/b/builders/clang-i386-freebsd/builds/18445

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206666 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-18 22:30:03 +00:00