Commit Graph

340 Commits

Author SHA1 Message Date
Owen Anderson
2cf7537dc6 Don't bother value numbering instructions with void types in GVN. In theory this should allow us to insert
fewer things into the value numbering maps, but any speedup is beneath the noise threshold on my machine
on 403.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122844 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 22:15:21 +00:00
Owen Anderson
b1602abe63 Complete the NumberTable --> LeaderTable rename.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122828 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 19:29:46 +00:00
Owen Anderson
a0709acd6f Fix typo in a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122827 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 19:25:18 +00:00
Owen Anderson
465942d008 Prune #include's.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122826 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 19:24:57 +00:00
Owen Anderson
7a75d6108e Clarify terminology, settling on referring to what was the "number table" as the "leader table", and
rename methods to make it much more clear what they're doing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122823 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 19:13:25 +00:00
Owen Anderson
680ac4ff4e When removing a value from GVN's leaders list, don't drop the Next pointer in a corner case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122822 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 19:10:54 +00:00
Owen Anderson
c2146a6abc Branch instructions don't produce values, so there's no need to generate a value number for them. This
avoids adding them to the various value numbering tables, resulting in a minor (~3%) speedup for GVN
on 40.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122819 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 18:54:18 +00:00
Owen Anderson
2802c7536f Remove commented out code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122817 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-04 18:22:08 +00:00
Owen Anderson
392249fcf3 Use the new addEscapingValue callback to update GlobalsModRef when GVN adds PHIs of GEPs. For the moment,
have GlobalsModRef handle this conservatively by simply removing the value from its maps.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122787 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-03 23:51:43 +00:00
Owen Anderson
30f4a559d7 Simplify GVN's value expression structure, allowing the elimination of a lot of
almost-but-not-quite-identical code.  No intended functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122760 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-03 19:00:11 +00:00
Chris Lattner
9fc5cdf77c split dom frontier handling stuff out to its own DominanceFrontier header,
so that Dominators.h is *just* domtree.  Also prune #includes a bit.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122714 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 22:09:33 +00:00
Owen Anderson
f056838956 Give GVN back the ability to perform simple conditional propagation on conditional branch values.
I still think that LVI should be handling this, but that capability is some ways off in the future,
and this matters for some significant benchmarks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122378 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 23:54:34 +00:00
Owen Anderson
491e0307a8 Remove dead code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122371 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 22:31:24 +00:00
Benjamin Kramer
aad94aa437 GVN's Expression is not POD-like (it contains a SmallVector). Simplify code while at it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122362 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 21:30:19 +00:00
Chris Lattner
459f4f8c25 tidy up
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122190 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 20:24:28 +00:00
Dan Gohman
f4177aa019 Preserve TBAA tags when doing load PRE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121921 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 23:53:55 +00:00
Dan Gohman
5034dd318a Move Value::getUnderlyingObject to be a standalone
function so that it can live in Analysis instead of
VMCore.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121885 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 20:02:24 +00:00
Chris Lattner
ed58a6f96f move GetPointerBaseWithConstantOffset out of GVN into ValueTracking.h
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120476 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 22:25:26 +00:00
Chris Lattner
fcf8d7c73d remove a fixed fixme
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120474 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 22:18:11 +00:00
Owen Anderson
68c26396c0 Document the new GVN number table structure.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119865 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-19 22:48:40 +00:00
Owen Anderson
a04a0649e1 Completely rework the datastructure GVN uses to represent the value number to leader mapping. Previously,
this was a tree of hashtables, and a query recursed into the table for the immediate dominator ad infinitum
if the initial lookup failed.  This led to really bad performance on tall, narrow CFGs.

We can instead replace it with what is conceptually a multimap of value numbers to leaders (actually
represented by a hashtable with a list of Value*'s as the value type), and then
determine which leader from that set to use very cheaply thanks to the DFS numberings maintained by
DominatorTree.  Because there are typically few duplicates of a given value, this scan tends to be
quite fast.  Additionally, we use a custom linked list and BumpPtr allocation to avoid any unnecessary
allocation in representing the value-side of the multimap.

This change brings with it a 15% (!) improvement in the total running time of GVN on 403.gcc, which I
think is pretty good considering that includes all the "real work" being done by MemDep as well.

The one downside to this approach is that we can no longer use GVN to perform simple conditional progation,
but that seems like an acceptable loss since we now have LVI and CorrelatedValuePropagation to pick up
the slack.  If you see conditional propagation that's not happening, please file bugs against LVI or CVP.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119714 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-18 18:32:40 +00:00
Duncan Sands
d32c4a1756 Remove dead code in GVN: now that SimplifyInstruction is called
systematically, CollapsePhi will always return null here.  Note
that CollapsePhi did an extra check, isSafeReplacement, which
the SimplifyInstruction logic does not do.  I think that check
was bogus - I guess we will soon find out!  (It was originally
added in commit 41998 without a testcase).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119456 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-17 04:05:21 +00:00
Duncan Sands
eff0581583 If dom tree information is available, make it possible to pass
it to get better phi node simplification.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119055 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-14 18:36:10 +00:00
Duncan Sands
88c3df7afb Have GVN simplify instructions as it goes. For example, consider
"%z = %x and %y".  If GVN can prove that %y equals %x, then it turns
this into "%z = %x and %x".  With the new code, %z will be replaced
with %x everywhere (and then deleted).  Previously %z would be value
numbered too, which is a waste of time.  Also, while a clever value
numbering algorithm would give %z the same value number as %x, our
current one doesn't do so (at least I don't think it does).  The new
logic has an essentially equivalent effect to what you would get if
%z was given the same value number as %x, i.e. it should make value
numbering smarter.  While there, get hold of target data once at the
start rather than a gazillion times all over the place.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118923 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-12 21:10:24 +00:00
Dan Gohman
6d8eb156e6 Add helper functions for computing the Location of load, store,
and vaarg instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118845 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-11 21:50:19 +00:00
Dan Gohman
075fb5d68f Enhance GVN to do more precise alias queries for non-local memory
references. For example, this allows gvn to eliminate the load in
this example:

  void foo(int n, int* p, int *q) {
    p[0] = 0;
    p[1] = 1;
    if (n) {
      *q = p[0];
    }
  }


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118714 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-10 20:37:15 +00:00
Dan Gohman
3355c4e598 Use getValueOperand() and getPointerOperand() on load and store
instructions instead of hard-coding operand numbers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118698 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-10 19:03:33 +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
2ab36d3502 Begin adding static dependence information to passes, which will allow us to
perform initialization without static constructors AND without explicit initialization
by the client.  For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve.  I hope to be able to relax
the latter requirement in the future.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116334 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-12 19:48:12 +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
7267e14327 Now that the profitable bits of EnableFullLoadPRE have been enabled by default, rip out the remainder.
Anyone interested in more general PRE would be better served by implementing it separately, to get real
anticipation calculation, etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115337 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-01 20:02:55 +00:00
Owen Anderson
722cc1f414 We do want to allow LoadPRE to perform LICM-like transformations: we already consider PHI nodes to be negligible for
code size (making this transform code size neutral), and it allows us to hoist values out of loops, which is always
a good thing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115205 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-30 20:53:04 +00:00
Owen Anderson
b0ba0f4170 LoadPRE was not properly checking that the load it was PRE'ing post-dominated the block it was being hoisted to.
Splitting critical edges at the merge point only addressed part of the issue; it is also possible for non-post-domination
to occur when the path from the load to the merge has branches in it.  Unfortunately, full anticipation analysis is
time-consuming, so for now approximate it.  This is strictly more conservative than real anticipation, so we will miss
some cases that real PRE would allow, but we also no longer insert loads into paths where they didn't exist before. :-)

This is a very slight net positive on SPEC for me (0.5% on average).  Most of the benchmarks are largely unaffected, but
when it pays off it pays off decently: 181.mcf improves by 4.5% on my machine.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114785 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-25 05:26:18 +00:00
Chris Lattner
17aa68055b zap dead code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113073 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-04 18:12:00 +00:00
Duncan Sands
fc6e29d4ab Reapply commit 112699, speculatively reverted by echristo, since
I'm sure it is harmless.  Original commit message:
If PrototypeValue is erased in the middle of using the SSAUpdator
then the SSAUpdator may access freed memory.  Instead, simply pass
in the type and name explicitly, which is all that was used anyway.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112810 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-02 08:14:03 +00:00
Eric Christopher
adc581f5cb Speculatively revert 112699 and 112702, they seem to be causing
self host errors on clang-x86-64.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112719 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-01 17:29:10 +00:00
Duncan Sands
4d588bceb0 If PrototypeValue is erased in the middle of using the SSAUpdator
then the SSAUpdator may access freed memory.  Instead, simply pass
in the type and name explicitly, which is all that was used anyway.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112699 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-01 10:29:33 +00:00
Chris Lattner
abd2a75900 remove dead proto
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112408 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-29 04:53:24 +00:00
Owen Anderson
5015b3417f Don't attempt the PRE inline asm calls, since we don't value number them yet. Fixes PR7835.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110489 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-07 00:20:35 +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
Gabor Greif
96f1d8ebdd mass elimination of reliance on automatic iterator dereferencing
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109103 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-22 13:36:47 +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
1d3ae029c4 cache result of operator* (found by inspection)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107971 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-09 14:48:08 +00:00
Gabor Greif
0814985887 cache result of operator*
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107969 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-09 14:36:49 +00:00
Gabor Greif
237e1da16a use getNumArgOperands instead of getNumOperands
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107272 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-30 09:17:53 +00:00
Gabor Greif
d883a9d1ed use ArgOperand API
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106730 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-24 10:17:17 +00:00
Gabor Greif
0a14be0693 use callsite to obtain all arguments
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106729 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-24 10:04:07 +00:00
Dan Gohman
fe60104ac9 Use pre-increment instead of post-increment when the result is not used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106542 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-22 15:08:57 +00:00