In order to speed up compile time and to avoid random timeouts we now
separately track assumptions and restrictions. In this context
assumptions describe parameter valuations we need and restrictions
describe parameter valuations we do not allow. During AST generation
we create a runtime check for both, whereas the one for the
restrictions is negated before a conjunction is build.
Except the In-Bounds assumptions we currently only track restrictions.
Differential Revision: http://reviews.llvm.org/D17247
llvm-svn: 262328
This allows to construct run-time checks for a scop without having to generate
a full AST. This is currently not taken advantage of in Polly itself, but
external users may benefit from this feature.
llvm-svn: 262009
Check the ModRefBehaviour of functions in order to decide whether or
not a call instruction might be acceptable.
Differential Revision: http://reviews.llvm.org/D5227
llvm-svn: 261866
The generated dedicated subregion exit block was assumed to have the same
dominance relation as the original exit block. This is incorrect if the exit
block receives other edges than only from the subregion, which results in that
e.g. the subregion's entry block does not dominate the exit block.
llvm-svn: 261865
Replace Scop::getStmtForBasicBlock and Scop::getStmtForRegionNode, and
add overloads for llvm::Instruction and llvm::RegionNode.
getStmtFor and overloads become the common interface to get the Stmt
that contains something. Named after LoopInfo::getLoopFor and
RegionInfo::getRegionFor.
llvm-svn: 261791
This is also be caught by the function verifier, but disconnected from
the place that produced it. Catch it already at creation to be able to
reason more directly about the cause.
llvm-svn: 261790
This allows other passes and transformations to use some of the existing AST
building infrastructure. This is not yet used in Polly itself.
llvm-svn: 261496
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
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
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
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
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
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
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
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
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
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
getAccessFor does not guarantee a certain access to be returned in case an
instruction is related to multiple accesses. However, in the vector code
generation we want to know the stride of the array access of a store
instruction. By using getArrayAccessFor we ensure we always get the correct
memory access.
This patch fixes a potential bug, but I was unable to produce a failing test
case. Several existing test cases cover this code, but all of them already
passed out of luck (or the specific but not-guaranteed order in which we build
memory accesses).
llvm-svn: 255715
When generating scalar loads/stores separately the vector code has not been
updated. This commit adds code to generate scalar loads for vector code as well
as code to assert in case scalar stores are encountered within a vector loop.
llvm-svn: 255714
When rewriting the access functions of load/store statements, we are only
interested in the actual array memory location. The current code just took
the very first memory access, which could be a scalar or an array access. As
a result, we failed to update access functions even though this was requested
via .jscop.
llvm-svn: 255713
This change should not change the behavior of Polly today, but it allows
external constants to be remapped e.g. when targetting multiple LLVM modules.
llvm-svn: 255506
Over time different vocabulary has been introduced to describe the different
memory objects in Polly, resulting in different - often inconsistent - naming
schemes in different parts of Polly. We now standartize this to the following
scheme:
KindArray, KindValue, KindPHI, KindExitPHI
| ------- isScalar -----------|
In most cases this naming scheme has already been used previously (this
minimizes changes and ensures we remain consistent with previous publications).
The main change is that we remove KindScalar to clearify the difference between
a scalar as a memory object of kind Value, PHI or ExitPHI and a value (former
KindScalar) which is a memory object modeling a llvm::Value.
We also move all documentation to the Kind* enum in the ScopArrayInfo class,
remove the second enum in the MemoryAccess class and update documentation to be
formulated from the perspective of the memory object, rather than the memory
access. The terms "Implicit"/"Explicit", formerly used to describe memory
accesses, have been dropped. From the perspective of memory accesses they
described the different memory kinds well - especially from the perspective of
code generation - but just from the perspective of a memory object it seems more
straightforward to talk about scalars and arrays, rather than explicit and
implicit arrays. The last comment is clearly subjective, though. A less
subjective reason to go for these terms is the historic use both in mailing list
discussions and publications.
llvm-svn: 255467
When introducing separate control flow for the original and optimized code we
introduce now a special 'ExitingBlock':
\ /
EnteringBB
|
SplitBlock---------\
_____|_____ |
/ EntryBB \ StartBlock
| (region) | |
\_ExitingBB_/ ExitingBlock
| |
MergeBlock---------/
|
ExitBB
/ \
This 'ExitingBlock' contains code such as the final_reloads for scalars, which
previously were just added to whichever statement/loop_exit/branch-merge block
had been generated last. Having an explicit basic block makes it easier to
find these constructs when looking at the CFG.
llvm-svn: 255107
Re-run canonicalization passes after Polly's code generation.
The set of passes currently added here are nearly all the passes between
--polly-position=early and --polly-position=before-vectorizer, i.e. all
passes that would usually run after Polly.
In order to run these only if Polly actually modified the code, we add a
function attribute "polly-optimzed" to a function that contains
generated code. The cleanup pass is skipped if the function does not
have this attribute.
There is no support by the (legacy) PassManager to run passes only under
some conditions. One could have wrapped all transformation passes to run
only when CodeGeneration changed the code, but the analyses would run
anyway. This patch creates an independent pass manager. The
disadvantages are that all analyses have to re-run even if preserved and
it does not honor compiler switches like the PassManagerBuilder does.
Differential Revision: http://reviews.llvm.org/D14333
llvm-svn: 254150
