65 Commits

Author SHA1 Message Date
Diego Novillo
55deff895d Fix vectorization remarks.
This patch changes the vectorization remarks to also inform when
vectorization is possible but not beneficial.

Added tests to exercise some loop remarks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207574 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 20:06:10 +00:00
Zinovy Nis
c5e41aed09 [OPENMP][LV][D3423] Respect Hints.Force meta-data for loops in LoopVectorizer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207512 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 08:55:11 +00:00
Hal Finkel
e30aa957e3 Implement X86TTI::getUnrollingPreferences
This provides an initial implementation of getUnrollingPreferences for x86.
getUnrollingPreferences is used by the generic (concatenation) unroller, which
is distinct from the unrolling done by the loop vectorizer. Many modern x86
cores have some kind of uop cache and loop-stream detector (LSD) used to
efficiently dispatch small loops, and taking full advantage of this requires
unrolling small loops (small here means 10s of uops).

These caches also have limits on the number of taken branches in the loop, and
so we also cap the loop unrolling factor based on the maximum "depth" of the
loop. This is currently calculated with a partial DFS traversal (partial
because it will stop early if the path length grows too much). This is still an
approximation, and one that is both conservative (because it does not account
for branches eliminated via block placement) and optimistic (because it is only
recording the maximum depth over minimum paths). Nevertheless, because the
loops that fit in these uop caches are so small, it is not clear how much the
details matter.

The original set of patches posted for review produced the following test-suite
performance results (from the TSVC benchmark) at that time:
  ControlLoops-dbl - 13% speedup
  ControlLoops-flt - 15% speedup
  Reductions-dbl - 7.5% speedup

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205348 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-01 18:50:34 +00:00
Hal Finkel
6bbb01bbf8 Move partial/runtime unrolling late in the pipeline
The generic (concatenation) loop unroller is currently placed early in the
standard optimization pipeline. This is a good place to perform full unrolling,
but not the right place to perform partial/runtime unrolling. However, most
targets don't enable partial/runtime unrolling, so this never mattered.

However, even some x86 cores benefit from partial/runtime unrolling of very
small loops, and follow-up commits will enable this. First, we need to move
partial/runtime unrolling late in the optimization pipeline (importantly, this
is after SLP and loop vectorization, as vectorization can drastically change
the size of a loop), while keeping the full unrolling where it is now. This
change does just that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205264 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-31 23:23:51 +00:00
Adam Nemet
4ffbb65494 [X86] Adjust cost of FP_TO_UINT v4f64->v4i32 as well
Pretty obvious follow-on to r205159 to also handle conversion from double
besides float.

Fixes <rdar://problem/16373208>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205253 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-31 21:54:48 +00:00
Adam Nemet
cb1800772a [X86] Adjust cost of FP_TO_UINT v8f32->v8i32
There is no direct AVX instruction to convert to unsigned.  I have some ideas
how we may be able to do this with three vector instructions but the current
backend just bails on this to get it scalarized.

See the comment why we need to adjust the cost returned by BasicTTI.

The test is a bit roundabout (and checks assembly rather than bit code) because
I'd like it to work even if at some point we could vectorize this conversion.

Fixes <rdar://problem/16371920>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205159 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-30 18:07:13 +00:00
Quentin Colombet
566abecc9f [X86][Vectorizer Cost Model] Correct vectorization cost model for v2i64->v2f64
and v4i64->v4f64.

The new costs match what we did for SSE2 and reflect the reality of our codegen.

<rdar://problem/16381225>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204884 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 00:52:16 +00:00
Jim Grosbach
e6cee9f723 add 'requires asserts' to test that needs it
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204882 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 00:20:42 +00:00
Jim Grosbach
f20d9ee6a6 X86: Correct vectorization cost model for v8f32->v8i8.
Fix the cost model to reflect the reality of our codegen.

rdar://16370633

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204880 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 00:04:11 +00:00
Chandler Carruth
93228f6199 [vectorizer] Tweak the way we do small loop runtime unrolling in the
loop vectorizer to not do so when runtime pointer checks are needed and
share code with the new (not yet enabled) load/store saturation runtime
unrolling. Also ensure that we only consider the runtime checks when the
loop hasn't already been vectorized. If it has, the runtime check cost
has already been paid.

I've fleshed out a test case to cover the scalar unrolling as well as
the vector unrolling and comment clearly why we are or aren't following
the pattern.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200530 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-31 10:51:08 +00:00
Arnold Schwaighofer
fb70e11bbc LoopVectorizer: Add a test case for unrolling of small loops that need a runtime
check.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200408 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-29 18:55:44 +00:00
Chandler Carruth
05d43d8b6f [vectorizer] Completely disable the block frequency guidance of the loop
vectorizer, placing it behind an off-by-default flag.

It turns out that block frequency isn't what we want at all, here or
elsewhere. This has been I think a nagging feeling for several of us
working with it, but Arnold has given some really nice simple examples
where the results are so comprehensively wrong that they aren't useful.

I'm planning to email the dev list with a summary of why its not really
useful and a couple of ideas about how to better structure these types
of heuristics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200294 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-28 09:10:41 +00:00
Chandler Carruth
5f61e70eac [vectorize] Initial version of respecting PGO in the vectorizer: treat
cold loops as-if they were being optimized for size.

Nothing fancy here. Simply test case included. The nice thing is that we
can now incrementally build on top of this to drive other heuristics.
All of the infrastructure work is done to get the profile information
into this layer.

The remaining work necessary to make this a fully general purpose loop
unroller for very hot loops is to make it a fully general purpose loop
unroller. Things I know of but am not going to have time to benchmark
and fix in the immediate future:

1) Don't disable the entire pass when the target is lacking vector
   registers. This really doesn't make any sense any more.
2) Teach the unroller at least and the vectorizer potentially to handle
   non-if-converted loops. This is trivial for the unroller but hard for
   the vectorizer.
3) Compute the relative hotness of the loop and thread that down to the
   various places that make cost tradeoffs (very likely only the
   unroller makes sense here, and then only when dealing with loops that
   are small enough for unrolling to not completely blow out the LSD).

I'm still dubious how useful hotness information will be. So far, my
experiments show that if we can get the correct logic for determining
when unrolling actually helps performance, the code size impact is
completely unimportant and we can unroll in all cases. But at least
we'll no longer burn code size on cold code.

One somewhat unrelated idea that I've had forever but not had time to
implement: mark all functions which are only reachable via the global
constructors rigging in the module as optsize. This would also decrease
the impact of any more aggressive heuristics here on code size.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200219 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-27 13:11:50 +00:00
Renato Golin
1de8133402 force vector width via cpu on vectorizer metadata enable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196669 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-07 21:46:08 +00:00
Renato Golin
3a6ea481a1 Move test to X86 dir
Test is platform independent, but I don't want to force vector-width, or
that could spoil the pragma test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196539 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-05 21:45:39 +00:00
Arnold Schwaighofer
b40f14eb89 LoopVectorizer: Truncate i64 trip counts of i32 phis if necessary
In signed arithmetic we could end up with an i64 trip count for an i32 phi.
Because it is signed arithmetic we know that this is only defined if the i32
does not wrap. It is therefore safe to truncate the i64 trip count to a i32
value.

Fixes PR18049.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195787 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-26 22:11:23 +00:00
Arnold Schwaighofer
4bc2e3a32d SLPVectorizer: Fix stale for Value pointer array
We are slicing an array of Value pointers and process those slices in a loop.
The problem is that we might invalidate a later slice by vectorizing a former
slice.

Use a WeakVH to track the pointer. If the pointer is deleted or RAUW'ed we can
tell.

The test case will only fail when running with libgmalloc.

radar://15498655

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195162 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-19 22:20:20 +00:00
Renato Golin
93fd763184 Fix broken builds by moving test to x86 dir
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193351 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-24 15:11:03 +00:00
Matt Arsenault
55cfb52aa3 Fix missing CHECK-LABELs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191853 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-02 20:29:00 +00:00
Hal Finkel
435798e96a Disable unrolling in the loop vectorizer when disabled in the pass manager
When unrolling is disabled in the pass manager, the loop vectorizer should also
not unroll loops. This will allow the -fno-unroll-loops option in Clang to
behave as expected (even for vectorizable loops). The loop vectorizer's
-force-vector-unroll option will (continue to) override the pass-manager
setting (including -force-vector-unroll=0 to force use of the internal
auto-selection logic).

In order to test this, I added a flag to opt (-disable-loop-unrolling) to force
disable unrolling through opt (the analog of -fno-unroll-loops in Clang). Also,
this fixes a small bug in opt where the loop vectorizer was enabled only after
the pass manager populated the queue of passes (the global_alias.ll test needed
a slight update to the RUN line as a result of this fix).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189499 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-28 18:33:10 +00:00
Daniel Dunbar
24ec2e5a72 [tests] Cleanup initialization of test suffixes.
- Instead of setting the suffixes in a bunch of places, just set one master
   list in the top-level config. We now only modify the suffix list in a few
   suites that have one particular unique suffix (.ml, .mc, .yaml, .td, .py).

 - Aside from removing the need for a bunch of lit.local.cfg files, this enables
   4 tests that were inadvertently being skipped (one in
   Transforms/BranchFolding, a .s file each in DebugInfo/AArch64 and
   CodeGen/PowerPC, and one in CodeGen/SI which is now failing and has been
   XFAILED).

 - This commit also fixes a bunch of config files to use config.root instead of
   older copy-pasted code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188513 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-16 00:37:11 +00:00
Stephen Lin
39f4e8d9cc Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.
This update was done with the following bash script:

  find test/Transforms -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc" $NAME; then
      TEMP=`mktemp -t temp`
      cp $NAME $TEMP
      sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
      while read FUNC; do
        sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP
      done
      mv $TEMP $NAME
    fi
  done


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186268 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 01:42:54 +00:00
Arnold Schwaighofer
7251a75f6e X86 cost model: Add cost for vectorized gather/scather
radar://14351991

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186189 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-12 19:16:07 +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
Manman Ren
2dc50d3067 TBAA: remove !tbaa from testing cases if not used.
This will make it easier to turn on struct-path aware TBAA since the metadata
format will change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180796 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-30 17:52:57 +00:00
Arnold Schwaighofer
a4b8b4ccc9 LoopVectorize: Scalarize padded types
This patch disables memory-instruction vectorization for types that need padding
bytes, e.g., x86_fp80 has 10 bytes store size with 6 bytes padding in darwin on
x86_64. Because the load/store vectorization is performed by the bit casting to
a packed vector, which has incompatible memory layout due to the lack of padding
bytes, the present vectorizer produces inconsistent result for memory
instructions of those types.
This patch checks an equality of the AllocSize of a scalar type and allocated
size for each vector element, to ensure that there is no padding bytes and the
array can be read/written using vector operations.

Patch by Daisuke Takahashi!

Fixes PR15758.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180196 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-24 16:16:01 +00:00
Arnold Schwaighofer
b03ad17536 LoopVectorizer: Bail out if we don't have datalayout we need it
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180195 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-24 16:15:58 +00:00
Pekka Jaaskelainen
2e59a125fc Call the potentially costly isAnnotatedParallel() only once.
Made the uniform write test's checks a bit stricter.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180119 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-23 16:44:43 +00:00
Pekka Jaaskelainen
a8958769ea Refuse to (even try to) vectorize loops which have uniform writes,
even if erroneously annotated with the parallel loop metadata.

Fixes Bug 15794: 
"Loop Vectorizer: Crashes with the use of llvm.loop.parallel metadata"



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180081 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-23 08:08:51 +00:00
Arnold Schwaighofer
ac2cc0170f LoopVectorizer: Pass OperandValueKind information to the cost model
Pass down the fact that an operand is going to be a vector of constants.

This should bring the performance of MultiSource/Benchmarks/PAQ8p/paq8p on x86
back. It had degraded to scalar performance due to my pervious shift cost change
that made all shifts expensive on x86.

radar://13576547

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178809 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-04 23:26:27 +00:00
Benjamin Kramer
13497b3aa7 X86TTI: Add accurate costs for itofp operations, based on the actual instruction counts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178459 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-01 10:23:49 +00:00
Arnold Schwaighofer
c184a5f4ca LoopVectorizer: Insert some white space to make test case more readable
Also remove some unneeded function attributes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177114 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-14 21:31:09 +00:00
Arnold Schwaighofer
e2188d9c43 Add missing asserts flag to test - it uses debug flags
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177102 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-14 19:01:58 +00:00
Arnold Schwaighofer
d517da33b7 LoopVectorize: Invert case when we use a vector cmp value to query select cost
We generate a select with a vectorized condition argument when the condition is
NOT loop invariant. Not the other way around.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177098 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-14 18:54:36 +00:00
Benjamin Kramer
35a4a0ca51 Force cpu in test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176702 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-08 17:01:18 +00:00
Benjamin Kramer
f22d9cfa6d Insert the reduction start value into the first bypass block to preserve domination.
Fixes PR15344.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176701 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-08 16:58:37 +00:00
Arnold Schwaighofer
5f0d9dbdf4 X86 cost model: Adjust cost for custom lowered vector multiplies
This matters for example in following matrix multiply:

int **mmult(int rows, int cols, int **m1, int **m2, int **m3) {
  int i, j, k, val;
  for (i=0; i<rows; i++) {
    for (j=0; j<cols; j++) {
      val = 0;
      for (k=0; k<cols; k++) {
        val += m1[i][k] * m2[k][j];
      }
      m3[i][j] = val;
    }
  }
  return(m3);
}

Taken from the test-suite benchmark Shootout.

We estimate the cost of the multiply to be 2 while we generate 9 instructions
for it and end up being quite a bit slower than the scalar version (48% on my
machine).

Also, properly differentiate between avx1 and avx2. On avx-1 we still split the
vector into 2 128bits and handle the subvector muls like above with 9
instructions.
Only on avx-2 will we have a cost of 9 for v4i64.

I changed the test case in test/Transforms/LoopVectorize/X86/avx1.ll to use an
add instead of a mul because with a mul we now no longer vectorize. I did
verify that the mul would be indeed more expensive when vectorized with 3
kernels:

for (i ...)
   r += a[i] * 3;
for (i ...)
  m1[i] = m1[i] * 3; // This matches the test case in avx1.ll
and a matrix multiply.

In each case the vectorized version was considerably slower.

radar://13304919

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176403 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-02 04:02:52 +00:00
Pekka Jaaskelainen
b3dedc2ef2 Forgot to 'svn add' the LoopVectorizer tests for the new parallel loop metadata, sorry.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175311 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-15 21:50:19 +00:00
NAKAMURA Takumi
f5b39cd8de Formatting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174380 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-05 15:32:16 +00:00
NAKAMURA Takumi
eec44ce834 llvm/test/Transforms/LoopVectorize/X86/vector_ptr_load_store.ll: "-debug" requires +Asserts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174379 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-05 15:32:10 +00:00
Arnold Schwaighofer
935645b765 Loop Vectorizer: Handle pointer stores/loads in getWidestType()
In the loop vectorizer cost model, we used to ignore stores/loads of a pointer
type when computing the widest type within a loop. This meant that if we had
only stores/loads of pointers in a loop we would return a widest type of 8bits
(instead of 32 or 64 bit) and therefore a vector factor that was too big.

Now, if we see a consecutive store/load of pointers we use the size of a pointer
(from data layout).

This problem occured in SingleSource/Benchmarks/Shootout-C++/hash.cpp (reduced
test case is the first test in vector_ptr_load_store.ll).

radar://13139343

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174377 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-05 15:08:02 +00:00
Pekka Jaaskelainen
d72b4d321e Made the min-trip-count-switch test X86-specific to avoid
breakage with builds without X86-support.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174052 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-31 10:33:22 +00:00
Nadav Rotem
0bbbc52dc8 LoopVectorizer: Implement a new heuristics for selecting the unroll factor.
We ignore the cpu frontend and focus on pipeline utilization. We do this because we
don't have a good way to estimate the loop body size at the IR level.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172964 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-20 05:24:29 +00:00
Nadav Rotem
bcdabadaf4 Change the cpu type in the test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172963 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-20 05:20:56 +00:00
Benjamin Kramer
c759dd5f83 Move test that depends on the x86 target into a target-specific directory.
Should fix the arm buildbot (which only builds the arm target).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172611 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-16 13:25:56 +00:00
Nadav Rotem
14925e6b88 ARM Cost model: Use the size of vector registers and widest vectorizable instruction to determine the max vectorization factor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172010 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-09 22:29:00 +00:00
Nadav Rotem
3c90b3d5fd Remove the -licm pass from the loop vectorizer test because the loop vectorizer does it now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171930 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-09 01:20:59 +00:00
Nadav Rotem
83be7b0dd3 Cost Model: Move the 'max unroll factor' variable to the TTI and add initial Cost Model support on ARM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171928 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-09 01:15:42 +00:00
Nadav Rotem
9a6c6a3736 LoopVectorizer: When we vectorizer and widen loops we process many elements at once. This is a good thing, except for
small loops. On small loops post-loop that handles scalars (and runs slower) can take more time to execute than the
rest of the loop. This patch disables widening of loops with a small static trip count.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171798 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 21:54:51 +00:00
Nadav Rotem
e503319874 LoopVectorizer:
1. Add code to estimate register pressure.
2. Add code to select the unroll factor based on register pressure.
3. Add bits to TargetTransformInfo to provide the number of registers.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171469 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-04 17:48:25 +00:00