We now always print the reason why the code did not pass the LLVM verifier and
we also allow to disable verfication with -polly-codegen-verify=false. Before
this change the first assertion had generally no information why or what might
have gone wrong and it was also impossible to -view-cfg without recompile. This
change makes debugging bugs that result in incorrect IR a lot easier.
llvm-svn: 261320
To support non-aligned accesses we introduce a virtual element size
for arrays that divides each access function used for this array. The
adjustment of the access function based on the element size of the
array was therefore moved after this virtual element size was
determined, thus after all accesses have been created.
Differential Revision: http://reviews.llvm.org/D17246
llvm-svn: 261226
After we moved isl_ctx into Scop, we need to free the isl_ctx after
freeing all isl objects, which requires the ScopInfo pass to be freed
at last. But this is not guaranteed by the PassManager, and we need
extra code to free the isl_ctx at the right time.
We introduced a shared pointer to manage the isl_ctx, and distribute
it to all analyses that create isl objects. As such, whenever we free
an analyses with the shared_ptr (and also free the isl objects which
are created by the analyses), we decrease the (shared) reference
counter of the shared_ptr by 1. Whenever the reference counter reach
0 in the releaseMemory function of an analysis, that analysis will
be the last one that hold any isl objects, and we can safely free the
isl_ctx with that analysis.
Differential Revision: http://reviews.llvm.org/D17241
llvm-svn: 261100
First support for this feature was committed in r259784. Support for
loop invariant load hoisting with different types was added by
Johannes Doerfert in r260045 and r260886.
llvm-svn: 260965
A load can only be invariant if its base pointer is invariant too. To
this end, we check if the base pointer is defined inside the region or
outside. In the former case we recursively check if we can (and
therefore will) hoist the base pointer too. Only if that happends we
can hoist the load.
llvm-svn: 260886
This reverts commit 98efa006c96ac981c00d2e386ec1102bce9f549a.
The fix was broken since we do not use AA in the ScopDetection anymore to
check for invariant accesses.
llvm-svn: 260884
Eliminate the global variable "InsnToMemAcc" to make Scop/ScopInfo become
more protable, such that we can safely use them in a CallGraphSCC pass.
Differential Revision: http://reviews.llvm.org/D17238
llvm-svn: 260863
Before this patch it could happen that we did not hoist a load that
was a base pointer of another load even though AA already declared the
first one as invariant (during ScopDetection). If this case arises we
will now skipt the "can be overwriten" check because in this case the
over-approximating nature causes us to generate broken code.
llvm-svn: 260862
The former ScopArrayInfo::updateSizes was implicitly divided into an
updateElementType and an updateSizes. Now this partitioning is
explicit.
llvm-svn: 260860
So far we separated constant factors from multiplications, however,
only when they are at the outermost level of a parameter SCEV. Now,
we also separate constant factors from the parameter SCEV if the
outermost expression is a SCEVAddRecExpr. With the changes to the
SCEVAffinator we can now improve the extractConstantFactor(...)
function at will without worrying about any other code part. Thus,
if needed we can implement a more comprehensive
extractConstantFactor(...) function that will traverse the SCEV
instead of looking only at the outermost level.
Four test cases were affected. One did not change much and the other
three were simplified.
llvm-svn: 260859
This reverts commit https://llvm.org/svn/llvm-project/polly/trunk@260853
We unfortunately still have two bugs left which show only up with
-polly-process-unprofitable and which I forgot to test before committing.
llvm-svn: 260854
First support for this feature was committed in r259784. Support for
loop invariant load hoisting with different types was added by Johannes
Doerfert in r260045. This fixed the last known bug.
llvm-svn: 260853
Since the origin AccFuncMap in ScopInfo is used by the underlying Scop
only, and it must stay alive until we delete the Scop. It will be better
if we simply move the origin AccFuncMap in ScopInfo into the Scop class.
llvm-svn: 260820
Make Scop become more portable such that we can use it in a CallGraphSCC pass.
The first step is to drop the analyses that are only used during Scop construction.
This patch drop LoopInfo from Scop.
llvm-svn: 260819
Make Scop become more portable such that we can use it in a CallGraphSCC pass.
The first step is to drop the analyses that are only used during Scop construction.
This patch drop DominatorTree from Scop.
llvm-svn: 260818
Make Scop become more portable such that we can use it in a CallGraphSCC pass.
The first step is to drop the analyses that are only used during Scop construction.
This patch drop ScopDecection from Scop.
llvm-svn: 260817
We now distinguish invariant loads to the same memory location if they
have different types. This will cause us to pre-load an invariant
location once for each type that is used to access it. However, we can
thereby avoid invalid casting, especially if an array is accessed
though different typed/sized invariant loads.
This basically reverts the changes in r260023 but keeps the test
cases.
llvm-svn: 260045
We also disable this feature by default, as there are still some issues in
combination with invariant load hoisting that slipped through my initial
testing.
llvm-svn: 260025
Invariant load hoisting of memory accesses with non-canonical element
types lacks support for equivalence classes that contain elements of
different width/size. This support should be added, but to get our buildbots
back to green, we disable load hoisting for memory accesses with non-canonical
element size for now.
llvm-svn: 260023
Always use access-instruction pointer type to load the invariant values.
Otherwise mismatches between ScopArrayInfo element type and memory access
element type will result in invalid casts. These type mismatches are after
r259784 a lot more common and also arise with types of different size, which
have not been handled before.
Interestingly, this change actually simplifies the code, as we now have only
one code path that is always taken, rather then a standard code path for the
common case and a "fixup" code path that replaces the standard code path in
case of mismatching types.
llvm-svn: 260009
The previously implemented approach is to follow value definitions and
create write accesses ("push defs") while searching for uses. This
requires the same relatively validity- and requirement conditions to be
replicated at multiple locations (PHI instructions, other instructions,
uses by PHIs).
We replace this by iterating over the uses in a SCoP ("pull in
requirements"), and add writes only when at least one read has been
added. It turns out to be simpler code because each use is only iterated
over once and writes are added for the first access that reads it. We
need another iteration to identify escaping values (uses not in the
SCoP), which also makes the difference between such accesses more
obvious. As a side-effect, the order of scalar MemoryAccess can change.
Differential Revision: http://reviews.llvm.org/D15706
llvm-svn: 259987
This allows code such as:
void multiple_types(char *Short, char *Float, char *Double) {
for (long i = 0; i < 100; i++) {
Short[i] = *(short *)&Short[2 * i];
Float[i] = *(float *)&Float[4 * i];
Double[i] = *(double *)&Double[8 * i];
}
}
To model such code we use as canonical element type of the modeled array the
smallest element type of all original array accesses, if type allocation sizes
are multiples of each other. Otherwise, we use a newly created iN type, where N
is the gcd of the allocation size of the types used in the accesses to this
array. Accesses with types larger as the canonical element type are modeled as
multiple accesses with the smaller type.
For example the second load access is modeled as:
{ Stmt_bb2[i0] -> MemRef_Float[o0] : 4i0 <= o0 <= 3 + 4i0 }
To support code-generating these memory accesses, we introduce a new method
getAccessAddressFunction that assigns each statement instance a single memory
location, the address we load from/store to. Currently we obtain this address by
taking the lexmin of the access function. We may consider keeping track of the
memory location more explicitly in the future.
We currently do _not_ handle multi-dimensional arrays and also keep the
restriction of not supporting accesses where the offset expression is not a
multiple of the access element type size. This patch adds tests that ensure
we correctly invalidate a scop in case these accesses are found. Both types of
accesses can be handled using the very same model, but are left to be added in
the future.
We also move the initialization of the scop-context into the constructor to
ensure it is already available when invalidating the scop.
Finally, we add this as a new item to the 2.9 release notes
Reviewers: jdoerfert, Meinersbur
Differential Revision: http://reviews.llvm.org/D16878
llvm-svn: 259784
Even though the commands still work, dragonegg has not been updated to work with
recent versions of LLVM. Consequently, only very old Polly versions (which we
do not support any more), can be used in this way.
This simplifies our documentation page.
llvm-svn: 259758
This includes some (optional) improvements to the isl scheduler, which we do not
use yet, as well as a fix for a bug previously also affecting Polly:
commit 662ee9b7d45ebeb7629b239d3ed43442e25bf87c
Author: Sven Verdoolaege <skimo@kotnet.org>
Date: Mon Jan 25 16:59:32 2016 +0100
isl_basic_map_realign: perform Gaussian elimination on result
Many parts of isl assume that Gaussian elimination has been
applied to the equality constraints. In particular singleton_extract_point
makes this assumption. The input to singleton_extract_point
may have undergone parameter alignment. This parameter alignment
(ultimately performed by isl_basic_map_realign) therefore
needs to make sure the result preserves this property
llvm-svn: 259757
We remove information for older versions of Polly and also shorten the overall
text. This should make it a lot easier for people to get to the important code
wight away.
llvm-svn: 259658
We support now code such as:
void multiple_types(char *Short, char *Float, char *Double) {
for (long i = 0; i < 100; i++) {
Short[i] = *(short *)&Short[2 * i];
Float[i] = *(float *)&Float[4 * i];
Double[i] = *(double *)&Double[8 * i];
}
}
To support such code we use as element type of the modeled array the smallest
element type of all original array accesses. Accesses with larger types are
modeled as multiple accesses with the smaller type.
For example the second load access is modeled as:
{ Stmt_bb2[i0] -> MemRef_Float[o0] : 4i0 <= o0 <= 3 + 4i0 }
To support jscop-rewritable memory accesses we need each statement instance to
only be assigned a single memory location, which will be the address at which
we load the value. Currently we obtain this address by taking the lexmin of
the access function. We may consider keeping track of the memory location more
explicitly in the future.
llvm-svn: 259587
We create separate functions for fixed-size multi-dimensional, parameteric-sized
multi-dimensional, as well as single-dimensional memory accesses to reduce the
complexity of a large monolithic function.
Suggested-by: Michael Kruse <llvm@meinersbur.de>
llvm-svn: 259522
There is no need to pass the size of the elements as the last size dimension
to ScopArrayInfo. This information is already available through the ElementType.
Tracking it twice is not only redundant but may result in inconsistencies.
llvm-svn: 259521
For schedule generation we assumed that the reverse post order traversal used by
the domain generation is sufficient, however it is not. Once a loop is
discovered, we have to completely traverse it, before we can generate the
schedule for any block/region that is only reachable through a loop exiting
block.
To this end, we add a "loop stack" that will keep track of loops we
discovered during the traversal but have not yet traversed completely.
We will never visit a basic block (or region) outside the most recent
(thus smallest) loop in the loop stack but instead queue such blocks
(or regions) in a waiting list. If the waiting list is not empty and
(might) contain blocks from the most recent loop in the loop stack the
next block/region to visit is drawn from there, otherwise from the
reverse post order iterator.
We exploit the new property of loops being always completed before additional
loops are processed, by removing the LoopSchedules map and instead keep all
information in LoopStack. This clarifies that we indeed always only keep a
stack of in-process loops, but will never keep incomplete schedules for an
arbitrary set of loops. As a result, we can simplify some of the existing code.
This patch also adds some more documentation about how our schedule construction
works.
This fixes http://llvm.org/PR25879
This patch is an modified version of Johannes Doerfert's initial fix.
Differential Revision: http://reviews.llvm.org/D15679
llvm-svn: 259354
In https://llvm.org/svn/llvm-project/polly/trunk@251870 code was committed to
avoid a failure in the presence of infinite loops, but the test case committed
along with this change passes without the actual change. I looked back into the
code and also checked with the original committer (Johannes), but could not find
the reason why the code is needed. The introduction of LoopStacks for
buildSchedule in one of the next commits will make it even more clear that this
code is not needed, but I remove this ahead of time to facilitate bisecting in
case I missed something.
llvm-svn: 259347
darwin requires the additional linkages of...
LLVMBitReader
LLVMMCParser
LLVMObject
LLVMProfileData
LLVMTarget
LLVMVectorize
as the darwin requires all of the weak undefined symbols in a library to be
resolved when linking it against an executable (unless
-Wl,-undefined,dynamic_lookup is used to override the default behavior of
-Wl,-undefined,error).
Contributed-by: Jack Howarth
llvm-svn: 259332
The autotools build system is based on and requires LLVM's autotools
build system to work, which has been depricated and finally removed in
r258861. Consequently we also remove the autotools build system from
Polly.
Differential Revision: http://reviews.llvm.org/D16655
llvm-svn: 259041
Before adding a MK_Value READ MemoryAccess, check whether the read is
necessary or synthesizable. Synthesizable values are later generated by
the SCEVExpander and therefore do not need to be transferred
explicitly. This can happen because the check for synthesizability has
presumbly been forgotten in the case where a phi's incoming value has
been defined in a different statement.
Differential Revision: http://reviews.llvm.org/D15687
llvm-svn: 258998
MemAccInst wraps the common members of LoadInst and StoreInst. Also use
of this class in:
- ScopInfo::buildMemoryAccess
- BlockGenerator::generateLocationAccessed
- ScopInfo::addArrayAccess
- Scop::buildAliasGroups
- Replace every use of polly::getPointerOperand
Reviewers: jdoerfert, grosser
Differential Revision: http://reviews.llvm.org/D16530
llvm-svn: 258947
Ensure that there is at most one phi write access per PHINode and
ScopStmt. In particular, this would be possible for non-affine
subregions with multiple exiting blocks. We replace multiple MAY_WRITE
accesses by one MUST_WRITE access. The written value is constructed
using a PHINode of all exiting blocks. The interpretation of the PHI
WRITE's "accessed value" changed from the incoming value to the PHI like
for PHI READs since there is no unique incoming value.
Because region simplification shuffles around PHI nodes -- particularly
with exit node PHIs -- the PHINodes at analysis time does not always
exist anymore in the code generation pass. We instead remember the
incoming block/value pair in the MemoryAccess.
Differential Revision: http://reviews.llvm.org/D15681
llvm-svn: 258809
Keep at most one value read MemoryAccess per value and statement;
multiple generated loads do not have any additional effect. As one such
MemoryAccess can cater multiple uses within the statement, the
AccessInstruction property is not unique any more and set to nullptr.
Differential Revision: http://reviews.llvm.org/D15510
llvm-svn: 258808
Ensure there is at most one write access per definition of an
llvm::Value. Keep track of already created value write access by using
a (dense) map.
Replace addValueWriteAccess by ensureValueStore which can be uses more
liberally without worrying to add redundant accesses. It will be used,
e.g. in a logical correspondant for value reads -- ensureValueReload --
to ensure that the expected definition has been written when loading it.
Differential Revision: http://reviews.llvm.org/D15483
llvm-svn: 258807
Both functions implement the same functionality, with the difference that
getNewScalarValue assumes that globals and out-of-scop scalars can be directly
reused without loading them from their corresponding stack slot. This is correct
for sequential code generation, but causes issues with outlining code e.g. for
OpenMP code generation. getNewValue handles such cases correctly.
Hence, we can replace getNewScalarValue with getNewValue. This is not only more
future proof, but also eliminates a bunch of code.
The only functionality that was available in getNewScalarValue that is lost
is the on-demand creation of scalar values. However, this is not necessary any
more as scalars are always loaded at the beginning of each basic block and will
consequently always be available when scalar stores are generated. As this was
not the case in older versions of Polly, it seems the on-demand loading is just
some older code that has not yet been removed.
Finally, generateScalarLoads also generated loads for values that are loop
invariant, available in GlobalMap and which are preferred over the ones loaded
in generateScalarLoads. Hence, we can just skip the code generation of such
scalar values, avoiding the generation of dead code.
Differential Revision: http://reviews.llvm.org/D16522
llvm-svn: 258799
Polly currently does not support irreducible control and it is probably not
worth supporting. This patch adds code that checks for irreducible control
and refuses regions containing irreducible control.
Polly traditionally had rather restrictive checks on the control flow structure
which would have refused irregular control, but within the last couple of months
most of the control flow restrictions have been removed. As part of this
generalization we accidentally allowed irregular control flow.
Contributed-by: Karthik Senthil and Ajith Pandel
llvm-svn: 258497
The test case we look at does not necessarily require irreducible control flow,
but a normal loop is sufficient to create a non-affine region containing more
than one basic block that dominates the exit node. We replace this irreducible
control flow with a normal loop for the following reasons:
1) This is easier to understand
2) We will subsequently commit a patch that ensures Polly does not process
irreducible control flow.
Within non-affine regions, we could possibly handle irreducible control flow.
llvm-svn: 258496
Polly recently got its own product in LLVM's bug tracker, which will make it
easier for people to file Polly bugs. This change updates the bugtracker links
on the Polly website.
llvm-svn: 258494
In Polly, after hoisting loop invariant loads outside loop, the alignment
information for hoisted loads are missing, this patch restore them.
Contributed-by: Lawrence Hu <lawrence@codeaurora.org>
Differential Revision: http://reviews.llvm.org/D16160
llvm-svn: 258105
When importing a schedule, do not verify the load/store alignment of
scalar accesses. Scalar loads/store are always created newly in code
generation with no alignment restrictions. Previously, scalar alignment
was checked if the access instruction happened to be a LoadInst or
StoreInst, but only its array (MK_Array) access is relevant.
This will be implicitly unit-tested when the access instruction of a
value read can be nullptr.
Differential Revision: http://reviews.llvm.org/D15680
llvm-svn: 257904
ISL 0.16 will change how sets are printed which breaks 117 unit tests
that text-compare printed sets. This patch re-formats most of these unit
tests using a script and small manual editing on top of that. When
actually updating ISL, most work is done by just re-running the script
to adapt to the changed output.
Some tests that compare IR and tests with single CHECK-lines that can be
easily updated manually are not included here.
The re-format script will also be committed afterwards. The per-test
formatter invocation command lines options will not be added in the near
future because it is ad hoc and would overwrite the manual edits.
Ideally it also shouldn't be required anymore because ISL's set printing
has become more stable in 0.16.
Differential Revision: http://reviews.llvm.org/D16095
llvm-svn: 257851
should perform loop interchanges itself.
This also fixes a bug we see due to the "loop-interchange" pass producing
incorrect IR when compiling linpack-pc.c from the LLVM test-suite with
"-polly-position=before-vectorizer".
Reviewed-by: Tobias Grosser <tobias@grosser.es>
llvm-svn: 257495
Call assumeNoOutOfBound only in updateDimensionality to process situations
when new dimensions are added and new bounds checks are required.
Contributed-by: Tobias Grosser, Gareev Roman
llvm-svn: 257170
This change clarifies that for Not-NonAffine-SubRegions we actually iterate over
the subnodes and for both NonAffine-SubRegions and BasicBlocks, we perform the
schedule construction. As a result, the tree traversal becomes trivial, the
special case for a scop consisting just of a single non-affine region
disappears and the indentation of the code is reduced.
No functional change intended.
llvm-svn: 256940
Providing an explicit PointerLikeTypeTraits implementation became necessary
since LLVM started in https://llvm.org/svn/llvm-project/llvm/trunk@256620
to automatically derive the pointer alignment from the pointer element type,
which does not work for incomplete types as used by isl. To ensure our code
still compiles, we provide an instantiation of PointerLikeTypeTraits for isl_id
which assumes no minimal alignment. isl pointers are likely to have a "higher"
alignment. We can exploit this later in case this becomes performance relevant.
llvm-svn: 256650
Tobias Grosser