Commit Graph

277 Commits

Author SHA1 Message Date
Bob Wilson
3bd19d753b Don't attempt load PRE when there is no real redundancy (i.e., the load is in
a loop and is itself the only dependency).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97526 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-02 00:09:29 +00:00
Bob Wilson
70704978af When GVN needs to split critical edges for load PRE, check all of the
predecessors before returning.  Otherwise, if multiple predecessor edges need
splitting, we only get one of them per iteration.  This makes a small but
measurable compile time improvement with -enable-full-load-pre.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97521 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-01 23:37:32 +00:00
Evan Cheng
19d417c346 MemoryDepAnalysis is not used if redundant load processing is disabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97512 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-01 22:23:12 +00:00
Bob Wilson
b29d7d2542 Revert r97245 which seems to be causing performance problems.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97366 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-28 05:34:05 +00:00
Bob Wilson
8561dcd730 Move the EnableFullLoadPRE flag from a separate command-line option to an
argument of createGVNPass and set it automatically for -O3.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97245 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-26 19:09:47 +00:00
Bob Wilson
60df9077eb Remove unused "NoPRE" parameter in GVN and createGVNPass().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97235 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-26 18:35:19 +00:00
Daniel Dunbar
6d8f2ca646 Reapply r97010, the speculative revert failed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97036 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-24 08:48:04 +00:00
Daniel Dunbar
8c0c99016b Speculatively revert r97010, "Add an argument to PHITranslateValue to specify
the DominatorTree. ...", in hopes of restoring poor old PPC bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97027 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-24 06:55:22 +00:00
Bob Wilson
9d2ed8e632 Add an argument to PHITranslateValue to specify the DominatorTree. If this
argument is non-null, pass it along to PHITranslateSubExpr so that it can
prefer using existing values that dominate the PredBB, instead of just
blindly picking the first equivalent value that it finds on a uselist.
Also when the DominatorTree is specified, have PHITranslateValue filter
out any result that does not dominate the PredBB.  This is basically just
refactoring the check that used to be in GetAvailablePHITranslatedSubExpr
and also in GVN.

Despite my initial expectations, this change does not affect the results
of GVN for any testcases that I could find, but it should help compile time.
Before this change, if PHITranslateSubExpr picked a value that does not
dominate, PHITranslateWithInsertion would then insert a new value, which GVN
would later determine to be redundant and would replace.  By picking a good
value to begin with, we save GVN the extra work of inserting and then
replacing a new value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97010 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-24 01:39:00 +00:00
Bob Wilson
188f428e4e Update memdep when load PRE inserts a new load, and add some debug output.
I don't have a small testcase for this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96890 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-23 05:55:00 +00:00
Bob Wilson
74175c2ca1 Erase deleted instructions from GVN's ValueTable. This fixes assertion
failures from ValueTable::verifyRemoved() when using -debug.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96805 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-22 21:39:41 +00:00
Bob Wilson
ae23daf63a Rename SuccessorNumber to GetSuccessorNumber.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96387 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 21:06:42 +00:00
Bob Wilson
484d4a30c0 Split critical edges as needed for load PRE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96378 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 19:51:59 +00:00
Bob Wilson
adb6f22671 Refactor to share code to find the position of a basic block successor in the
terminator's list of successors.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96377 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 19:49:17 +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
Devang Patel
be905e26f6 Ignore dbg info intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95828 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-11 00:20:49 +00:00
Bob Wilson
e7b635f430 Fix some comment typos.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95170 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-03 00:33:21 +00:00
Bob Wilson
6cad41778e Add an option to GVN to remove all partially redundant loads. This is currently
disabled by default.  This divides the existing load PRE code into 2 phases:
first it checks that it is safe to move the load to each of the predecessors
where it is unavailable, and then if it is safe, the code is changed to move
the load.  Radar 7571861.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95007 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-01 21:17:14 +00:00
Bob Wilson
49db68fba0 Check alignment of loads when deciding whether it is safe to execute them
unconditionally.  Besides checking the offset, also check that the underlying
object is aligned as much as the load itself.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94875 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-30 04:42:39 +00:00
Bob Wilson
3eb4f7e2dd Improve isSafeToLoadUnconditionally to recognize that GEPs with constant
indices are safe if the result is known to be within the bounds of the
underlying object.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94829 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-29 19:19:08 +00:00
Bob Wilson
0988639963 Remove check for an impossible condition: the condition of the while loop has
already checked that TmpBB->getSinglePredecessor() is non-null.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94451 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-25 21:28:05 +00:00
Owen Anderson
a81e241fcc Convert some of the dynamic opcode lookups into static ones.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93693 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-17 19:33:27 +00:00
Dan Gohman
321a813c53 Use do+while instead of while for loops which obviously have a
non-zero trip count. Use SmallVector's pop_back_val().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92734 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 16:27:25 +00:00
David Greene
bf7f78e625 Change errs() to dbgs().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92613 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 01:27:17 +00:00
Chris Lattner
a53cfd16f0 split code that doesn't need to be templated out of IRBuilder into a new
non-templated IRBuilderBase class.  Move that large CreateGlobalString
out of line, eliminating the need to #include GlobalVariable.h in IRBuilder.h


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92227 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-28 21:28:46 +00:00
Chris Lattner
0ee443d169 The phi translated pointer can be computed when returning a partially cached result
instead of stored.  This reduces memdep memory usage, and also eliminates a bunch of
weakvh's.  This speeds up gvn on gcc.c-torture/20001226-1.c from 23.9s to 8.45s (2.8x)
on a different machine than earlier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91885 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-22 04:25:02 +00:00
Chris Lattner
d2191e549b Add a fastpath to Load GVN to special case when we have exactly one dominating
load to avoid even messing around with SSAUpdate at all.  In this case (which
is very common, we can just use the input value directly).

This speeds up GVN time on gcc.c-torture/20001226-1.c from 36.4s to 16.3s,
which still isn't great, but substantially better and this is a simple speedup
that applies to lots of different cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91851 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-21 23:15:48 +00:00
Chris Lattner
5362c545e8 refactor some code out to a new helper method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91849 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-21 23:04:33 +00:00
Dan Gohman
ad12b2698b Eliminte unnecessary uses of <cstdio>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91666 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-18 03:25:51 +00:00
Chris Lattner
4bbf4ee149 Remove isPod() from DenseMapInfo, splitting it out to its own
isPodLike type trait.  This is a generally useful type trait for
more than just DenseMap, and we really care about whether something
acts like a pod, not whether it really is a pod.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91421 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-15 07:26:43 +00:00
Chris Lattner
16f244e982 Fix PR5744, a case where we were getting the pointer size instead of the
value size.  This only manifested when memdep inprecisely returns clobber,
which is do to a caching issue in the PR5744 testcase.  We can 'efficiently
emulate' this by using '-no-aa'


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91004 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-10 00:11:45 +00:00
Chris Lattner
b6760b4a1e allow this to build when the #if 0's are enabled. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90999 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-10 00:04:46 +00:00
Chris Lattner
af064aeee6 fix hte last remaining known (by me) phi translation bug. When we reanalyze
clobbers to forward pieces of large stores to small loads, we need to consider
the properly phi translated pointer in the store block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90978 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 18:21:46 +00:00
Chris Lattner
b2c6ae8c0b change GetStoreValueForLoad to use IRBuilder, which is cleaner and
implicitly constant folds.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90977 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 18:13:28 +00:00
Chris Lattner
4ca70fe15f change AnalyzeLoadFromClobberingMemInst/AnalyzeLoadFromClobberingStore
to require the load ty/ptr to be passed in, no functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90960 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 07:37:07 +00:00
Chris Lattner
03f17da4da change AnalyzeLoadFromClobberingWrite and clients to pass in type
and pointer instead of the load.  No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90959 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 07:34:10 +00:00
Chris Lattner
e18b97121c change NonLocalDepEntry from being a typedef for an std::pair to be its
own small class.  No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90956 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 07:08:01 +00:00
Chris Lattner
b3f927f6dd add some aborts to #if 0's.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90929 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 02:41:54 +00:00
Chris Lattner
05e15f8897 Switch GVN and memdep to use PHITransAddr, which correctly handles
phi translation of complex expressions like &A[i+1].  This has the
following benefits:

1. The phi translation logic is all contained in its own class with
   a strong interface and verification that it is self consistent.

2. The logic is more correct than before.  Previously, if intermediate
   expressions got PHI translated, we'd miss the update and scan for
   the wrong pointers in predecessor blocks.  @phi_trans2 is a testcase
   for this.

3. We have a lot less code in memdep.

We can handle phi translation across blocks of things like @phi_trans3,
which is pretty insane :).

This patch should fix the miscompiles of 255.vortex, and I tested it 
with a bootstrap of llvm-gcc, llvm-test and dejagnu of course.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90926 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 01:59:31 +00:00
Chris Lattner
bc9a28dd54 constant fold loads from memcpy's from global constants. This is important
because clang lowers nontrivial automatic struct/array inits to memcpy from
a global array.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90698 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-06 05:29:56 +00:00
Chris Lattner
cb9cbc4949 add support for forwarding mem intrinsic values to non-local loads.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90697 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-06 04:54:31 +00:00
Chris Lattner
faf815b938 Handle forwarding local memsets to loads. For example, we optimize this:
short x(short *A) {
  memset(A, 1, sizeof(*A)*100);
  return A[42];
}

to 'return 257' instead of doing the load.  



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90695 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-06 01:57:02 +00:00
Owen Anderson
c9f2027adb Fix this crasher, and add a FIXME for a missed optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90408 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-03 03:43:29 +00:00
Owen Anderson
9ff5a23186 Cleanup/remove some parts of the lifetime region handling code in memdep and GVN,
per Chris' comments.  Adjust testcases to match.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90304 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-02 07:35:19 +00:00
Chris Lattner
720e790480 factor some code better.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90299 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-02 06:44:58 +00:00
Chris Lattner
0c264b16b0 reenable load address insertion in load pre. This allows us to
handle cases like this:
void test(int N, double* G) {
  long j;
  for (j = 1; j < N - 1; j++)
      G[j+1] = G[j] + G[j+1];
}

where G[1] isn't live into the loop.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90041 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-28 16:08:18 +00:00
Chris Lattner
dd696052f0 Enhance InsertPHITranslatedPointer to be able to return a list of newly
inserted instructions.  No functionality change until someone starts using it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90039 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-28 15:39:14 +00:00
Chris Lattner
971fd57f7d disable value insertion for now, I need to figure out how
to inform GVN about the newly inserted values.  This fixes 
PR5631.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90022 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 22:50:07 +00:00
Chris Lattner
6f7b210b25 Rework InsertPHITranslatedPointer to handle the recursive case, this
fixes PR5630 and sets the stage for the next phase of goodness (testcase
pending).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90019 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 22:05:15 +00:00
Chris Lattner
616613d7a4 teach GVN's load PRE to insert computations of the address in predecessors
where it is not available.  It's unclear how to get this inserted 
computation into GVN's scalar availability sets, Owen, help? :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89997 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 08:25:10 +00:00