Commit Graph

181 Commits

Author SHA1 Message Date
Matt Arsenault
eba6d38448 Scalarize select vector arguments when extracted.
When the elements are extracted from a select on vectors
or a vector select, do the select on the extracted scalars
from the input if there is only one use.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194013 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-04 20:36:06 +00:00
Arnold Schwaighofer
f4775827d0 LoopVectorizer: Perform redundancy elimination on induction variables
When the loop vectorizer was part of the SCC inliner pass manager gvn would
run after the loop vectorizer followed by instcombine. This way redundancy
(multiple uses) were removed and instcombine could perform scalarization on the
induction variables. Having moved the loop vectorizer to later we no longer run
any form of redundancy elimination before we perform instcombine. This caused
vectorized induction variables to survive that did not before.

On a recent iMac this helps linpack back from 6000Mflops to 7000Mflops.

This should also help lpbench and paq8p.

I ran a Release (without Asserts) build over the test-suite and did not see any
negative impact on compile time.

radar://15339680

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193891 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-01 22:18:19 +00:00
Benjamin Kramer
7208b0763c LoopVectorize: Look for consecutive acces in GEPs with trailing zero indices
If we have a pointer to a single-element struct we can still build wide loads
and stores to it (if there is no padding).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193860 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-01 14:09:50 +00:00
Arnold Schwaighofer
0097e15502 LoopVectorizer: If dependency checks fail try runtime checks
When a dependence check fails we can still try to vectorize loops with runtime
array bounds checks.

This helps linpack to vectorize a loop in dgefa. And we are back to 2x of the
scalar performance on a corei7-avx.

radar://15339680

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193853 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-01 03:05:07 +00:00
Arnold Schwaighofer
c04d241d13 ARM cost model: Unaligned vectorized double stores are expensive
Updated a test case that assumed that <2 x double> would vectorize to use
<4 x float>.

radar://15338229

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193574 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-29 01:33:57 +00:00
Hal Finkel
006183a936 LoopVectorizer: Don't attempt to vectorize extractelement instructions
The loop vectorizer does not currently understand how to vectorize
extractelement instructions. The existing check, which excluded all
vector-valued instructions, did not catch extractelement instructions because
it checked only the return value. As a result, vectorization would proceed,
producing illegal instructions like this:

  %58 = extractelement <2 x i32> %15, i32 0
  %59 = extractelement i32 %58, i32 0

where the second extractelement is illegal because its first operand is not a vector.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193434 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-25 20:40:15 +00:00
Renato Golin
e662fb6083 I had to move and remove
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193355 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-24 16:31:43 +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
Renato Golin
d6aa89eca5 Mark vector loops as already vectorized
Make sure we mark all loops (scalar and vector) when vectorizing,
so that we don't try to vectorize them anymore. Also, set unroll
to 1, since this is what we check for on early exit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193349 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-24 14:50:51 +00:00
Arnold Schwaighofer
1ee3c0008b LoopVectorize: External uses must use the last value in a reduction cycle
Otherwise, we don't perform operations that would have been performed on
the scalar version.

Fixes PR17498.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192133 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-07 21:05:43 +00:00
Matt Arsenault
407847f130 Don't use runtime bounds check between address spaces.
Don't vectorize with a runtime check if it requires a
comparison between pointers with different address spaces.
The values can't be assumed to be directly comparable.
Previously it would create an illegal bitcast.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191862 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-02 22:38:17 +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
Manman Ren
e267f04ef5 TBAA: update tbaa format from scalar format to struct-path aware format.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191690 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-30 18:17:55 +00:00
Manman Ren
aef1b37824 TBAA: remove !tbaa from testing cases when they are not needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191689 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-30 18:17:35 +00:00
Arnold Schwaighofer
4e7b015a4a Revert "LoopVectorizer: Only allow vectorization of intrinsics."
Revert 191122 - with extra checks we are allowed to vectorize math library
function calls.

Standard library indentifiers are reserved names so functions with external
linkage must not overrided them. However, functions with internal linkage can.

Therefore, we can vectorize calls to math library functions with a check for
external linkage and matching signature. This matches what we do during
SelectionDAG building.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191206 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-23 14:54:39 +00:00
Nadav Rotem
2ecd8c90b0 LoopVectorizer: Only allow vectorization of intrinsics. We can't know for sure that the functions 'abs' or 'round' are the functions from libm.
rdar://15012650



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191122 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-21 00:27:05 +00:00
Chandler Carruth
89ec610f76 Name the XCore target-specific subdirectories canonically.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190940 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-18 14:08:30 +00:00
NAKAMURA Takumi
fa7b1e24e5 A couple of tests, in llvm/test/Transforms/*/xcore, are XCore-specific. They should be excluded when XCore is not built.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190938 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-18 13:56:16 +00:00
Robert Lytton
d072d1b2a3 Prevent LoopVectorizer and SLPVectorizer running if the target has no vector registers.
XCore target: Add XCoreTargetTransformInfo
This is where getNumberOfRegisters() resides, which in turn returns the
number of vector registers (=0).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190936 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-18 12:43:35 +00:00
Arnold Schwaighofer
5721d2f674 Don't vectorize if there are outside loop users of the induction variable.
We would have to compute the pre increment value, either by computing it on
every loop iteration or by splitting the edge out of the loop and inserting a
computation for it there.

For now, just give up vectorizing such loops.

Fixes PR17179.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190790 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-16 16:17:24 +00:00
Matt Arsenault
a03e32d397 Fix missing CHECK-LABELs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190426 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-10 19:57:05 +00:00
Manman Ren
1ed2e1fb92 Debug Info Testing: update context from empty string to null.
Context should be either null or MDNode.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190267 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-08 03:11:54 +00:00
Manman Ren
1307103dff Debug Info Testing: updated to use NULL instead of "i32 0" in a few fields.
Field 2 of DIType (Context), field 9 of DIDerivedType (TypeDerivedFrom),
field 12 of DICompositeType (ContainingType), fields 2, 7, 12 of DISubprogram
(Context, Type, ContainingType).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190205 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-06 21:03:58 +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
Manman Ren
6e3cd0ebe2 Debug Info: add an identifier field to DICompositeType.
DICompositeType will have an identifier field at position 14. For now, the
field is set to null in DIBuilder.
For DICompositeTypes where the template argument field (the 13th field)
was optional, modify DIBuilder to make sure the template argument field is set.
Now DICompositeType has 15 fields.

Update DIBuilder to use NULL instead of "i32 0" for null value of a MDNode.
Update verifier to check that DICompositeType has 15 fields and the last
field is null or a MDString.

Update testing cases to include an extra field for DICompositeType.
The identifier field will be used by type uniquing so a front end can
genearte a DICompositeType with a unique identifer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189282 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-26 22:39:55 +00:00
Nadav Rotem
4bf6326d08 LoopVectorize: Implement partial loop unrolling when vectorization is not profitable.
This patch enables unrolling of loops when vectorization is legal but not profitable.
We add a new class InnerLoopUnroller, that extends InnerLoopVectorizer and replaces some of the vector-specific logic with scalars.

This patch does not introduce any runtime regressions and improves the following workloads:

SingleSource/Benchmarks/Shootout/matrix -22.64%
SingleSource/Benchmarks/Shootout-C++/matrix -13.06%
External/SPEC/CINT2006/464_h264ref/464_h264ref  -3.99%
SingleSource/Benchmarks/Adobe-C++/simple_types_constant_folding -1.95%



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189281 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-26 22:33:26 +00:00
Manman Ren
094637408b [Debug Info Tests] Update testing cases.
A single metadata will not span multiple lines. This also helps me with
my script to automatic update the testing cases.
A debug info testing case should have a llvm.dbg.cu.
Do not use hard-coded id for debug nodes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189033 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-22 17:11:18 +00:00
Matt Arsenault
978de6b56a Teach LoopVectorize about address space sizes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188980 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-22 02:42:55 +00:00
Hal Finkel
66d1fa6f4b Add a llvm.copysign intrinsic
This adds a llvm.copysign intrinsic; We already have Libfunc recognition for
copysign (which is turned into the FCOPYSIGN SDAG node). In order to
autovectorize calls to copysign in the loop vectorizer, we need a corresponding
intrinsic as well.

In addition to the expected changes to the language reference, the loop
vectorizer, BasicTTI, and the SDAG builder (the intrinsic is transformed into
an FCOPYSIGN node, just like the function call), this also adds FCOPYSIGN to a
few lists in LegalizeVector{Ops,Types} so that vector copysigns can be
expanded.

In TargetLoweringBase::initActions, I've made the default action for FCOPYSIGN
be Expand for vector types. This seems correct for all in-tree targets, and I
think is the right thing to do because, previously, there was no way to generate
vector-values FCOPYSIGN nodes (and most targets don't specify an action for
vector-typed FCOPYSIGN).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188728 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-19 23:35:46 +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
Hal Finkel
41418d17cc Add ISD::FROUND for libm round()
All libm floating-point rounding functions, except for round(), had their own
ISD nodes. Recent PowerPC cores have an instruction for round(), and so here I'm
adding ISD::FROUND so that round() can be custom lowered as well.

For the most part, this is straightforward. I've added an intrinsic
and a matching ISD node just like those for nearbyint() and friends. The
SelectionDAG pattern I've named frnd (because ISD::FP_ROUND has already claimed
fround).

This will be used by the PowerPC backend in a follow-up commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187926 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-07 22:49:12 +00:00
Arnold Schwaighofer
2d66d4cf42 LoopVectorize: Allow vectorization of loops with lifetime markers
Patch by Marc Jessome!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187825 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-06 22:37:52 +00:00
Bill Wendling
61fc8d670f Use function attributes to indicate that we don't want to realign the stack.
Function attributes are the future! So just query whether we want to realign the
stack directly from the function instead of through a random target options
structure.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187618 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-01 21:42:05 +00:00
Manman Ren
d513b4033f Debug Info: update testing cases to pass verifier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187362 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-29 18:12:58 +00:00
Rafael Espindola
16a0de5b4a Next batch of -disable-debug-info-verifier.
These tests fail without it if pipefail is enabled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187205 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-26 14:16:30 +00:00
Stephen Lin
15bfd6d3ad Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.
This conversion 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/;\(.*\)\([A-Za-z0-9_]*\):\( *\)define\([^@]*\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3define\4@$FUNC(/g" $TEMP
      done
      mv $TEMP $NAME
    fi
  done


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186269 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 01:50:49 +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
ae4e1a94e3 LoopVectorizer: Disallow reductions whose header phi is used outside the loop
If an outside loop user of the reduction value uses the header phi node we
cannot just reduce the vectorized phi value in the vector code epilog because
we would loose VF-1 reductions.

lp:
  p = phi (0, lv)
  lv = lv + 1
  ...
  brcond , lp, outside

outside:
  usr = add 0, p

(Say the loop iterates two times, the value of p coming out of the loop is one).

We cannot just transform this to:

vlp:
  p = phi (<0,0>, lv)
  lv = lv + <1,1>
  ..
  brcond , lp, outside

outside:
  p_reduced = p[0] + [1];
  usr = add 0, p_reduced

(Because the original loop iterated two times the vectorized loop would iterate
one time, but p_reduced ends up being zero instead of one).

We would have to execute VF-1 iterations in the scalar remainder loop in such
cases. For now, just disable vectorization.

PR16522

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186256 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-13 19:09:29 +00:00
Andrew Trick
18382fff41 Make the new vectorizer test immune to TTI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186242 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-13 06:40:33 +00:00
Andrew Trick
9a26e1320b LoopVectorize fix: LoopInfo must be valid when invoking utils like SCEVExpander.
In general, one should always complete CFG modifications first, update
CFG-based analyses, like Dominatores and LoopInfo, then generate
instruction sequences.

LoopVectorizer was creating a new loop, calling SCEVExpander to
generate checks, then updating LoopInfo. I just changed the order.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186241 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-13 06:20:06 +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
Arnold Schwaighofer
4a1c764264 ARM cost model: Add cost for gather/scather
Fixes a 35% degradation compared to unvectorized code in
MiBench/automotive-susan and an equally serious regression on a private
image processing benchmark.

radar://14351991

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186188 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-12 19:16:04 +00:00
Arnold Schwaighofer
11eb51e239 LoopVectorize: Vectorize all accesses in address space zero with unit stride
We can vectorize them because in the case where we wrap in the address space the
unvectorized code would have had to access a pointer value of zero which is
undefined behavior in address space zero according to the LLVM IR semantics.
(Thank you Duncan, for pointing this out to me).

Fixes PR16592.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186088 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-11 15:21:55 +00:00
Arnold Schwaighofer
c14380d195 LoopVectorize: Math functions only read rounding mode
Math functions are mark as readonly because they read the floating point
rounding mode. Because we don't vectorize loops that would contain function
calls that set the rounding mode it is safe to ignore this memory read.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185299 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-01 00:54:44 +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
e2b9912a78 Fix spelling.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185052 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 01:01:11 +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