4 Commits

Author SHA1 Message Date
Arnold Schwaighofer
9660ebb398 SLPVectorize: Put horizontal reductions feeding a store under separate flag
Put them under a separate flag for experimentation. They are more likely to
interfere with loop vectorization which happens later in the pass pipeline.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191371 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-25 14:02:32 +00:00
Arnold Schwaighofer
a9baf1ecfd Reapply "SLPVectorizer: Handle more horizontal reductions (disabled)""
Reapply r191108 with a fix for a memory corruption error I introduced.  Of
course, we can't reference the scalars that we replace by vectorizing and then
call their eraseFromParent method. I only 'needed' the scalars to get the
DebugLoc. Just store the DebugLoc before actually vectorizing instead. As a nice
side effect, this also simplifies the interface between BoUpSLP and the
HorizontalReduction class to returning a value pointer (the vectorized tree
root).

radar://14607682

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191123 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-21 01:06:00 +00:00
Arnold Schwaighofer
74d3482f76 Revert "SLPVectorizer: Handle more horizontal reductions (disabled)"
This reverts commit r191108.

The horizontal.ll test case fails under libgmalloc. Thanks Shuxin for pointing
this out to me.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191121 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-21 00:06:20 +00:00
Arnold Schwaighofer
074e489dbc SLPVectorizer: Handle more horizontal reductions (disabled)
Match reductions starting at binary operation feeding into a phi. The code
handles trees like

 r += v1 + v2 + v3 ...

and

 r += v1
 r += v2
 ...

and

 r *= v1 + v2 + ...

We currently only handle associative operations (add, fadd fast).

The code can now also handle reductions feeding into stores.

 a[i] = v1 + v2 + v3 + ...

The code is currently disabled behind the flag "-slp-vectorize-hor".  The cost
model for most architectures is not there yet.

I found one opportunity of a horizontal reduction feeding a phi in TSVC
(LoopRerolling-flt) and there are several opportunities where reductions feed
into stores.

radar://14607682

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191108 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-20 21:18:20 +00:00