Commit Graph

368 Commits

Author SHA1 Message Date
Arnold Schwaighofer b0f11e3701 LoopVectorize: Use static function instead of DebugLocSetter class
I used the class to safely reset the state of the builder's debug location.  I
think I have caught all places where we need to set the debug location to a new
one. Therefore, we can replace the class by a function that just sets the debug
location.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185165 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-28 16:26:54 +00:00
Arnold Schwaighofer 57a7da8b23 LoopVectorize: Preserve debug location info
radar://14169017

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185122 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-28 00:38:54 +00:00
Arnold Schwaighofer 0bbbf7cbb0 LoopVectorize: Cache edge masks created during if-conversion
Otherwise, we end up with an exponential IR blowup.
Fixes PR16472.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185097 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 20:31:06 +00:00
Arnold Schwaighofer 0862d589ee LoopVectorize: Use vectorized loop invariant gep index anchored in loop
Use vectorized instruction instead of original instruction anchored in the
original loop.

Fixes PR16452 and t2075.c of PR16455.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185081 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 15:11:55 +00:00
Arnold Schwaighofer 45ef457b8f LoopVectorize: Don't store a reversed value in the vectorized value map
When we store values for reversed induction stores we must not store the
reversed value in the vectorized value map. Another instruction might use this
value.

This fixes 3 test cases of PR16455.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185051 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 00:45:41 +00:00
Arnold Schwaighofer bc7c58d2b1 Reapply 184685 after the SetVector iteration order fix.
This should hopefully have fixed the stage2/stage3 miscompare on the dragonegg
testers.

"LoopVectorize: Use the dependence test utility class

We now no longer need alias analysis - the cases that alias analysis would
handle are now handled as accesses with a large dependence distance.

We can now vectorize loops with simple constant dependence distances.

  for (i = 8; i < 256; ++i) {
    a[i] = a[i+4] * a[i+8];
  }

  for (i = 8; i < 256; ++i) {
    a[i] = a[i-4] * a[i-8];
  }

We would be able to vectorize about 200 more loops (in many cases the cost model
instructs us no to) in the test suite now. Results on x86-64 are a wash.

I have seen one degradation in ammp. Interestingly, the function in which we
now vectorize a loop is never executed so we probably see some instruction
cache effects. There is a 2% improvement in h264ref. There is one or the other
TSCV loop kernel that speeds up.

radar://13681598"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184724 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 12:09:15 +00:00
Arnold Schwaighofer 7e96b4dfce LoopVectorize: Use SetVector for the access set
We are creating the runtime checks using this set so we need a deterministic
iteration order.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184723 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 12:09:12 +00:00
Arnold Schwaighofer ec677e2a64 Revert "LoopVectorize: Use the dependence test utility class"
This reverts commit cbfa1ca993.

We are seeing a stage2 and stage3 miscompare on some dragonegg bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184690 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 06:10:41 +00:00
Arnold Schwaighofer cbfa1ca993 LoopVectorize: Use the dependence test utility class
We now no longer need alias analysis - the cases that alias analysis would
handle are now handled as accesses with a large dependence distance.

We can now vectorize loops with simple constant dependence distances.

  for (i = 8; i < 256; ++i) {
    a[i] = a[i+4] * a[i+8];
  }

  for (i = 8; i < 256; ++i) {
    a[i] = a[i-4] * a[i-8];
  }

We would be able to vectorize about 200 more loops (in many cases the cost model
instructs us no to) in the test suite now. Results on x86-64 are a wash.

I have seen one degradation in ammp. Interestingly, the function in which we
now vectorize a loop is never executed so we probably see some instruction
cache effects. There is a 2% improvement in h264ref. There is one or the other
TSCV loop kernel that speeds up.

radar://13681598

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184685 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 03:55:48 +00:00
Arnold Schwaighofer 5df684a6d1 LoopVectorize: Add utility class for checking dependency among accesses
This class checks dependences by subtracting two Scalar Evolution access
functions allowing us to catch very simple linear dependences.

The checker assumes source order in determining whether vectorization is safe.
We currently don't reorder accesses.
Positive true dependencies need to be a multiple of VF otherwise we impede
store-load forwarding.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184684 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 03:55:45 +00:00
Arnold Schwaighofer 5737d3f433 LoopVectorize: Add utility class for building sets of dependent accesses
Sets of dependent accesses are built by unioning sets based on underlying
objects. This class will be used by the upcoming dependence checker.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184683 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-24 03:55:44 +00:00
Pekka Jaaskelainen a8a04380c5 Fix for a regression caused by the LoopVectorizer when
vectorizing loops with memory accesses to non-zero address spaces. It
simply dropped the AS info. Fixes PR16306.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184103 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-17 18:49:06 +00:00
Arnold Schwaighofer 35b4cf868e LoopVectorize: Change API call to get the backedge taken count
Use ScalarEvolution's getBackedgeTakenCount API instead of getExitCount since
that is really what we want to know. Using the more specific getExitCount was
safe because we made sure that there is only one exiting block.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183047 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-31 21:48:56 +00:00
Arnold Schwaighofer 47afc19625 LoopVectorize: PHIs with only outside users should prevent vectorization
We check that instructions in the loop don't have outside users (except if
they are reduction values). Unfortunately, we skipped this check for
if-convertable PHIs.

Fixes PR16184.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183035 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-31 19:53:50 +00:00
NAKAMURA Takumi 0cf4adbcef LoopVectorize.cpp: Fix abuse of StringRef on Twine. Twine captures the pointer of StringRef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182820 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-29 03:13:47 +00:00
NAKAMURA Takumi 51c292a360 Whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182819 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-29 03:13:41 +00:00
Paul Redmond ee21b6f7b4 Add support for llvm.vectorizer metadata
- llvm.loop.parallel metadata has been renamed to llvm.loop to be more generic
  by making the root of additional loop metadata.
  - Loop::isAnnotatedParallel now looks for llvm.loop and associated
    llvm.mem.parallel_loop_access
  - document llvm.loop and update llvm.mem.parallel_loop_access
- add support for llvm.vectorizer.width and llvm.vectorizer.unroll
  - document llvm.vectorizer.* metadata
  - add utility class LoopVectorizerHints for getting/setting loop metadata
  - use llvm.vectorizer.width=1 to indicate already vectorized instead of
    already_vectorized
- update existing tests that used llvm.loop.parallel and
  llvm.vectorizer.already_vectorized

Reviewed by: Nadav Rotem


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182802 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-28 20:00:34 +00:00
Benjamin Kramer 959ecb2eec LoopVectorize: LoopSimplify can't canonicalize loops with an indirectbr in it, don't assert on those cases.
Fixes PR16139.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182656 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-24 18:05:35 +00:00
Arnold Schwaighofer 6e4a9c14f6 LoopVectorize: Make Value pointers that could be RAUW'ed a VH
The Value pointers we store in the induction variable list can be RAUW'ed by a
call to SCEVExpander::expandCodeFor, use a TrackingVH instead. Do the same thing
in some other places where we store pointers that could potentially be RAUW'ed.

Fixes PR16073.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182485 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-22 16:54:56 +00:00
Arnold Schwaighofer 688b5103eb LoopVectorize: Handle single edge PHIs
We might encouter single edge PHIs - handle them with an identity select.

Fixes PR15990.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182199 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-18 18:38:34 +00:00
Benjamin Kramer c53bee6eae LoopVectorize: Simplify code. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182100 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-17 14:48:17 +00:00
Arnold Schwaighofer 0aad08adfd LoopVectorize: Move call of canHoistAllLoads to canVectorizeWithIfConvert
We only want to check this once, not for every conditional block in the loop.

No functionality change (except that we don't perform a check redudantly
anymore).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181942 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-15 22:38:14 +00:00
Arnold Schwaighofer e3ab7cca3a LoopVectorize: Fix comments
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181862 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-15 02:02:45 +00:00
Arnold Schwaighofer 1386692ef6 LoopVectorize: Hoist conditional loads if possible
InstCombine can be uncooperative to vectorization and sink loads into
conditional blocks. This prevents vectorization.

Undo this optimization if there are unconditional memory accesses to the same
addresses in the loop.

radar://13815763

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181860 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-15 01:44:30 +00:00
Arnold Schwaighofer 123f18bcb9 LoopVectorize: Handle loops with multiple forward inductions
We used to give up if we saw two integer inductions. After this patch, we base
further induction variables on the chosen one like we do in the reverse
induction and pointer induction case.

Fixes PR15720.

radar://13851975

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181746 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-14 00:21:18 +00:00