Commit Graph

193 Commits

Author SHA1 Message Date
Duncan Sands
20b2d21509 Stop reassociate from looking through expressions of arbitrary complexity. This
is a temporary measure until my fix for PR13021 is ready.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160778 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-26 09:26:40 +00:00
Nadav Rotem
a94d6e87c4 Clean whitespaces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160668 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-24 10:51:42 +00:00
Nadav Rotem
c1deb67d78 Suppress a warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160629 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-23 13:44:15 +00:00
Duncan Sands
2923bca2b5 Rework this to clarify where the removal of nodes from the queue is
really happening.  No intended functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159451 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-29 19:03:05 +00:00
Duncan Sands
96d2eff5c6 Fix a reassociate crash on sozefx when compiling with dragonegg+gcc-4.7 due to
the optimizers producing a multiply expression with more multiplications than
the original (!).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159426 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-29 13:25:06 +00:00
Chandler Carruth
06cb8ed006 Move llvm/Support/IRBuilder.h -> llvm/IRBuilder.h
This was always part of the VMCore library out of necessity -- it deals
entirely in the IR. The .cpp file in fact was already part of the VMCore
library. This is just a mechanical move.

I've tried to go through and re-apply the coding standard's preferred
header sort, but at 40-ish files, I may have gotten some wrong. Please
let me know if so.

I'll be committing the corresponding updates to Clang and Polly, and
Duncan has DragonEgg.

Thanks to Bill and Eric for giving the green light for this bit of cleanup.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159421 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-29 12:38:19 +00:00
Duncan Sands
2d5f8ca3d1 Some reassociate optimizations create new instructions, which they insert just
before the expression root.  Any existing operators that are changed to use one
of them needs to be moved between it and the expression root, and recursively
for the operators using that one.  When I rewrote RewriteExprTree I accidentally
inverted the logic, resulting in the compacting going down from operators to
operands rather than up from operands to the operators using them, oops.  Fix
this, resolving PR12963.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159265 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-27 14:19:00 +00:00
Nick Lewycky
917f99354f Remove a dangling reference to a deleted instruction. Fixes PR13185!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159096 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-24 01:44:08 +00:00
Duncan Sands
cd117f736c Fix issues (infinite loop and/or crash) with self-referential instructions, for
example degenerate phi nodes and binops that use themselves in unreachable code.
Thanks to Charles Davis for the testcase that uncovered this can of worms.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158508 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-15 08:37:50 +00:00
Duncan Sands
d34491f675 It is possible for several constants which aren't individually absorbing to
combine to the absorbing element.  Thanks to nbjoerg on IRC for pointing this 
out.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158399 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-13 12:15:56 +00:00
Duncan Sands
ee5a094ccf When linearizing a multiplication, return at once if we see a factor of zero,
since then the entire expression must equal zero (similarly for other operations
with an absorbing element).  With this in place a bunch of reassociate code for
handling constants is dead since it is all taken care of when linearizing.  No
intended functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158398 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-13 09:42:13 +00:00
Duncan Sands
5f9e4c1189 Use DenseMap as SmallMap workaround rather than std::map, at Chandler's request.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158371 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-12 20:26:43 +00:00
Duncan Sands
ac071eac30 Use std::map rather than SmallMap because SmallMap assumes that the value has
POD type, causing memory corruption when mapping to APInts with bitwidth > 64.
Merge another crash testcase into crash.ll while there.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158369 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-12 20:16:51 +00:00
Duncan Sands
c038a78335 Now that Reassociate's LinearizeExprTree can look through arbitrary expression
topologies, it is quite possible for a leaf node to have huge multiplicity, for
example: x0 = x*x, x1 = x0*x0, x2 = x1*x1, ... rapidly gives a value which is x
raised to a vast power (the multiplicity, or weight, of x).  This patch fixes
the computation of weights by correctly computing them no matter how big they
are, rather than just overflowing and getting a wrong value.  It turns out that
the weight for a value never needs more bits to represent than the value itself,
so it is enough to represent weights as APInts of the same bitwidth and do the
right overflow-avoiding dance steps when computing weights.  As a side-effect it
reduces the number of multiplies needed in some cases of large powers.  While
there, in view of external uses (eg by the vectorizer) I made LinearizeExprTree
static, pushing the rank computation out into users.  This is progress towards
fixing PR13021.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158358 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-12 14:33:56 +00:00
Duncan Sands
841f426175 Reapply commit 158073 with a fix (the testcase was already committed). The
problem was that by moving instructions around inside the function, the pass
could accidentally move the iterator being used to advance over the function
too.  Fix this by only processing the instruction equal to the iterator, and
leaving processing of instructions that might not be equal to the iterator
to later (later = after traversing the basic block; it could also wait until
after traversing the entire function, but this might make the sets quite big).
Original commit message:

Grab-bag of reassociate tweaks.  Unify handling of dead instructions and
instructions to reoptimize.  Exploit this to more systematically eliminate
dead instructions (this isn't very useful in practice but is convenient for
analysing some testcase I am working on).  No need for WeakVH any more: use
an AssertingVH instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158226 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-08 20:15:33 +00:00
Duncan Sands
69938a85bd Revert commit 158073 while waiting for a fix. The issue is that reassociate
can move instructions within the instruction list.  If the instruction just
happens to be the one the basic block iterator is pointing to, and it is
moved to a different basic block, then we get into an infinite loop due to
the iterator running off the end of the basic block (for some reason this
doesn't fire any assertions).  Original commit message:

Grab-bag of reassociate tweaks.  Unify handling of dead instructions and
instructions to reoptimize.  Exploit this to more systematically eliminate
dead instructions (this isn't very useful in practice but is convenient for
analysing some testcase I am working on).  No need for WeakVH any more: use
an AssertingVH instead.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158199 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-08 13:37:30 +00:00
Duncan Sands
b933586592 Grab-bag of reassociate tweaks. Unify handling of dead instructions and
instructions to reoptimize.  Exploit this to more systematically eliminate
dead instructions (this isn't very useful in practice but is convenient for
analysing some testcase I am working on).  No need for WeakVH any more: use
an AssertingVH instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158073 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-06 14:53:10 +00:00
Benjamin Kramer
d9b0b02561 Fix typos found by http://github.com/lyda/misspell-check
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157885 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-02 10:20:22 +00:00
Duncan Sands
eacc31acf5 Since commit 157467, if reassociate isn't actually going to change an expression
then it doesn't alter the instructions composing it, however it would continue
to move the instructions to just before the expression root.  Ensure it doesn't
move them either, so now it really does nothing if there is nothing to do.  That
commit also ensured that nsw etc flags weren't cleared if the expression was not
being changed.  Tweak this a bit so that it doesn't clear flags on the initial
part of a computation either if that part didn't change but later bits did.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157518 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-26 16:42:52 +00:00
Duncan Sands
24dfa52fa2 Move this debug statement earlier so it is easy to see the order in
which operands come flying out of the linearization stage.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157512 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-26 07:47:48 +00:00
Duncan Sands
0fd120b970 Make the reassociation pass more powerful so that it can handle expressions
with arbitrary topologies (previously it would give up when hitting a diamond
in the use graph for example).  The testcase from PR12764 is now reduced from
a pile of additions to the optimal 1617*%x0+208.  In doing this I changed the
previous strategy of dropping all uses for expression leaves to one of dropping
all but one use.  This works out more neatly (but required a bunch of tweaks)
and is also safer: some recently fixed bugs during recursive linearization were
because the linearization code thinks it completely owns a node if it has no uses
outside the expression it is linearizing.  But if the node was also in another
expression that had been linearized (and thus all uses of the node from that
expression dropped) then the conclusion that it is completely owned by the
expression currently being linearized is wrong.  Keeping one use from within each
linearized expression avoids this kind of mistake.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157467 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-25 12:03:02 +00:00
Duncan Sands
a337010989 Calling ReassociateExpression recursively is extremely dangerous since it will
replace the operands of expressions with only one use with undef and generate
a new expression for the original without using RAUW to update the original.
Thus any copies of the original expression held in a vector may end up
referring to some bogus value - and using a ValueHandle won't help since there
is no RAUW.  There is already a mechanism for getting the effect of recursion
non-recursively: adding the value to be recursed on to RedoInsts.  But it wasn't
being used systematically.  Have various places where recursion had snuck in at
some point use the RedoInsts mechanism instead.  Fixes PR12169.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156379 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-08 12:16:05 +00:00
Owen Anderson
423f19f2da Teach reassociate to commute FMul's and FAdd's in order to canonicalize the order of their operands across instructions. This allows for greater CSE opportunities.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156323 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-07 20:47:23 +00:00
Bill Wendling
98bda3dfef Add 'landingpad' instructions to the list of instructions to ignore.
Also combine the code in the 'assert' statement.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156155 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-04 04:22:32 +00:00
Bill Wendling
e8cd3f2491 Whitespace cleanup.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156034 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-02 23:43:23 +00:00
Bill Wendling
55e7098bbc The value held in the vector may be RAUW'ed by some of the canonicalization
methods. Use a weak value handle to keep up with this.
PR12245


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155984 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-02 09:59:45 +00:00
Chandler Carruth
464bda3a16 Teach the reassociate pass to fold chains of multiplies with repeated
elements to minimize the number of multiplies required to compute the
final result. This uses a heuristic to attempt to form near-optimal
binary exponentiation-style multiply chains. While there are some cases
it misses, it seems to at least a decent job on a very diverse range of
inputs.

Initial benchmarks show no interesting regressions, and an 8%
improvement on SPASS. Let me know if any other interesting results (in
either direction) crop up!

Credit to Richard Smith for the core algorithm, and helping code the
patch itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155616 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-26 05:30:30 +00:00
Craig Topper
f1d0f7781e Prune some includes and forward declarations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153429 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-26 06:58:25 +00:00
Duncan Sands
1f6a329f79 Silence a bunch (but not all) "variable written but not read" warnings
when building with assertions disabled.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137460 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-12 14:54:45 +00:00
Owen Anderson
9b7fdc7e8a Revert r136503 and r136480 in an effort to fix non-determinism in the llvm-gcc buildbots on i386. Devang is looking into the root cause.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136674 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-02 02:23:42 +00:00
Devang Patel
6e8bb8a0cb Clear DbgValues in the end.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136503 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-29 19:49:58 +00:00
Devang Patel
1619560521 Clean up debug info after reassociation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136480 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-29 19:00:35 +00:00
Chris Lattner
c73b24db5f start using the new helper methods a bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135251 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-15 06:08:15 +00:00
Devang Patel
5367b23f76 Preserve line number information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130450 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-28 22:48:14 +00:00
Dan Gohman
dac5dbadeb Fix reassociate to use a worklist instead of recursing when new
reassociation opportunities are exposed. This fixes a bug where
the nested reassociation expects to be the IR to be consistent,
but it isn't, because the outer reassociation has disconnected
some of the operands.  rdar://9167457


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129324 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-12 00:11:56 +00:00
Dan Gohman
c9f2f61d34 RecursivelyDeleteTriviallyDeadInstructions only needs a
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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127427 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-10 20:57:44 +00:00
Dan Gohman
fa0e6facc7 Fix reassociate to postpone certain instruction deletions until
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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127424 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-10 19:51:54 +00:00
Chris Lattner
de1d8a544c fix PR9215, preventing -reassociate from clearing nsw/nuw when
it swaps the LHS/RHS of a single binop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125700 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-17 01:29:24 +00:00
Dan Gohman
46985a1440 Fix reassociate to clear optional flags, such as nsw.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124712 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-02 02:02:34 +00:00
Duncan Sands
37f87c7aa9 Fix PR9039, a use-after-free in reassociate. The issue was that the
operand being factorized (and erased) could occur several times in Ops,
resulting in freed memory being used when the next occurrence in Ops was
analyzed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124287 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 10:08:38 +00:00
Owen Anderson
081c34b725 Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116820 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-19 17:21:58 +00:00
Owen Anderson
ce665bd2e2 Now with fewer extraneous semicolons!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115996 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07 22:25:06 +00:00
Owen Anderson
90c579de5a Reapply r110396, with fixes to appease the Linux buildbot gods.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110460 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06 18:33:48 +00:00
Owen Anderson
1f74590e9d Revert r110396 to fix buildbots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110410 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06 00:23:35 +00:00
Owen Anderson
9ccaf53ada Don't use PassInfo* as a type identifier for passes. Instead, use the address of the static
ID member as the sole unique type identifier.  Clean up APIs related to this change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110396 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-05 23:42:04 +00:00
Owen Anderson
d13db2c59c Fix batch of converting RegisterPass<> to INTIALIZE_PASS().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109045 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-21 22:09:45 +00:00
Gabor Greif
110b75aa75 cache dereferenced iterators
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108138 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-12 12:03:02 +00:00
Chris Lattner
893075f46e fix a nice subtle reassociate bug which would only occur
in a very specific use pattern embodied in the carefully
reduced testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97794 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-05 07:18:54 +00:00
Duncan Sands
1df9859c40 There are two ways of checking for a given type, for example isa<PointerType>(T)
and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96344 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 11:11:14 +00:00
Duncan Sands
b0bc6c361d Uniformize the names of type predicates: rather than having isFloatTy and
isInteger, we now have isFloatTy and isIntegerTy.  Requested by Chris!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96223 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-15 16:12:20 +00:00