Summary: This patch updates the isl interface used in `foldSizeConstantsToRight()` to the new C++ interface.
Reviewers: chelini, grosser, philip.pfaffe, Meinersbur
Reviewed By: grosser
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48965
llvm-svn: 336362
This change has no impact on upstream Polly directly, but reduces output
noise for some internal isl versions we are testing. In general, storing
simpler and more canonical output is a good idea. Hence, it seems useful
to upstream this change.
llvm-svn: 336281
Summary: This patch aims to provide support for detecting load patterns which are collectively invariant but right now `isHoistableLoad()` is checking each load instruction individually which cannot detect the load pattern as a whole.
Patch by: Sahil Girish Yerawar
Reviewers: bollu, philip.pfaffe, Meinersbur
Reviewed By: philip.pfaffe, Meinersbur
Differential Revision: https://reviews.llvm.org/D48026
llvm-svn: 335949
First build the surrounding loops and then build up the polyhedral
structures. Before r326664 we had to mix these updates, clean this
up to improve readability (slightly).
llvm-svn: 334412
In case the schedule has not changed and the operand tree root uses a
value defined in an ancestor loop, the def-to-target mapping is trivial.
For instance, the SCoP
for (int i < 0; i < N; i+=1) {
DefStmt:
D = ...;
for (int j < 0; j < N; j+=1) {
TargetStmt:
use(D);
}
}
has DefStmt-to-TargetStmt mapping of
{ DefStmt[i] -> TargetStmt[i,j] }
This should apply on the majority of def-to-target mappings.
This patch detects this case and directly constructs the expected
mapping. It assumes that the mapping never crosses the loop header
DefStmt is in, which ForwardOpTree does not support at the moment
anyway.
Differential Revision: https://reviews.llvm.org/D47752
llvm-svn: 334134
Summary: This patch updates `Scop::addUserContext()` function to the new C++ interface and replaces the `auto` keyword with explicit type wherever used in this function.
Reviewers: grosser, bollu, philip.pfaffe, chelini, Meinersbur
Reviewed By: grosser
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47438
llvm-svn: 333366
Summary: This patch aims to remove the usage of old C-styled isl functions (in this case `isl_set_n_basic_set()`) in favor of new C++ isl interface based methods in `ScopInfo.cpp`.
Patch by Sahil Yerawar
Differential Revision: https://reviews.llvm.org/D46935
llvm-svn: 332471
Summary: Creating the Scop name is expensive, because creating the
Region name it's derived from is expensive. So create the name lazily,
because getName() is actually called rarely.
This is a reiteration of r328666, which introduced a use-after-free and
got reverted in r331363.
Differential Revision: https://reviews.llvm.org/D46868
llvm-svn: 332359
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
Differential Revision: https://reviews.llvm.org/D44978
llvm-svn: 332352
The condition was introduced in r267142 to mitigate a long compile-time
case. In r306087, a max-computation limit was introduced that should
handle the same case while leaving the max disjuncts heuristic it
should have replaced intact.
Today, the max disjuncts bail-out causes problems in that it prematurely
stops SCoPs from being detected, e.g. in SPEC's lbm. This would hit less
like if isl_set_coalesce would be called after isl_set_remove_divs
(which makes more basic_set likely to be coalescable) instead of before.
This patch tries to remove the premature max-disjuncts bail-out
condition by using simple_hull() to reduce the computational overhead,
instead of directly invalidating that SCoP.
Differential Revision: https://reviews.llvm.org/D45066
Contributed-by: Sahil Girish Yerawar <cs15btech11044@iith.ac.in>
llvm-svn: 331891
This reverts commit 0f9dc03765dc301fff7a52e2a0e1dd3e5f3130c5, r328666.
The change introduced a use-after-free, caused by the temporary name string
being destroyed after converting it to a StringRef.
llvm-svn: 331363
The current statement domain derivation algorithm does not (always)
consider that different exit blocks of a loop can have different
conditions to be reached.
From the code
for (int i = n; ; i-=2) {
if (i <= 0) goto even;
if (i <= 1) goto odd;
A[i] = i;
}
even:
A[0] = 42;
return;
odd:
A[1] = 21;
return;
Polly currently derives the following domains:
Stmt_even_critedge
Domain :=
[n] -> { Stmt_even_critedge[] };
Stmt_odd
Domain :=
[n] -> { Stmt_odd[] : (1 + n) mod 2 = 0 and n > 0 };
while the domain for the odd case is correct, Stmt_even is assumed to be
executed unconditionally, which is obviously wrong. While projecting out
the loop dimension in `adjustDomainDimensions`, it does not consider
that there are other exit condition that have matched before.
I don't know a how to fix this without changing a lot of code. Therefore
This patch rejects loops with multiple exist blocks to fix the
miscompile of test-suite's uuencode.
The odd condition is transformed by LLVM to
%cmp1 = icmp eq i64 %indvars.iv, 1
such that the project_out in adjustDomainDimensions() indeed only
matches for odd n (using this condition only, we'd have an infinite loop
otherwise).
The even condition manifests as
%cmp = icmp slt i64 %indvars.iv, 3
Because buildDomainsWithBranchConstraints() does not consider other exit
conditions, it has to assume that the induction variable will eventually
be lower than 3 and taking this exit.
IMHO we need to reuse the algorithm that determines the number of
iterations (addLoopBoundsToHeaderDomain) to determine which exit
condition applies first. It has to happen in
buildDomainsWithBranchConstraints() because the result will need to
propagate to successor BBs. Currently addLoopBoundsToHeaderDomain() just
look for union of all backedge conditions (which means leaving not the
loop here). The patch in llvm.org/PR35465 changes it to look for exit
conditions instead. This is required because there might be other exit
conditions that do not alternatively go back to the loop header.
Differential Revision: https://reviews.llvm.org/D45649
llvm-svn: 330858
Add the switch -polly-debug-func to define the name of a debug
function. This function is ignored for any validity check.
Its purpose is to allow to observe a value after transformation by a
SCoP, and to follow which statements are executed in which order. For
instance, consider the following code:
static void dbg_printf(int sum, int i) {
fprintf(stderr, "The value of sum is %d, i=%d\n", sum, i);
fflush(stderr);
}
void func(int n) {
int sum = 0;
for (int i = 0; i < 16; i+=1) {
sum += i;
dbg_printf(sum, i);
}
}
Executing this after Polly's codegen with -polly-debug-func=dbg_printf
reveals the new execution order and the assumed values at that point of
execution.
Differential Revision: https://reviews.llvm.org/D45728
llvm-svn: 330466
Commit r329640 introduced the removal of all MemoryAccesses of a Scop.
It accidentally continued iterating over a vector whose iterators
have been invalidated by a MemoryAccess removal.
Make a copy of the MemoryAccesses to remove to iterate over while
removing them.
llvm-svn: 329653
Removing a statement left its MemoryAccesses in some lists and maps of
the SCoP. Which lists depends on at which phase of the SCoP
construction the statement is deleted. Follow-up passes could still see
the already deleted MemoryAccesses by iterating through these
lists/maps, resulting in an access violation.
When removing a ScopStmt, also remove all its MemoryAccesses by using
the same mechnism that removes a MemoryAccess.
llvm-svn: 329640
std::remove, despite its name, does not remove elements from a list, but
only moves them to the end of a list. Call erase() to shorten the
vector to the remaining elements.
Test case included in next commit.
llvm-svn: 329639
Summary:
When checking the parallelism of a scheduling dimension, we first check if excluding reduction dependences the loop is parallel or not.
If the loop is not parallel, then we need to return the minimal dependence distance of all data dependences, including the previously subtracted reduction dependences.
Reviewers: grosser, Meinersbur, efriedma, eli.friedman, jdoerfert, bollu
Reviewed By: Meinersbur
Subscribers: llvm-commits, pollydev
Tags: #polly
Differential Revision: https://reviews.llvm.org/D45236
llvm-svn: 329214
This gets very expensive for basic blocks which don't have a name: it
calls printAsOperand, which numbers the entire module. We don't
normally need the name anyway, though; it's only used for debug dumps,
so don't compute it by default.
Differential Revision: https://reviews.llvm.org/D44946
llvm-svn: 328666
isl does not guarantee that set dimension ids will be preserved, so using them
to carry information is not a good idea. Furthermore, the loop information can
be derived without problem from the statement itself. As this even requires
less code than propagating loop information on set dimension ids, starting from
this commit we just derive the loop information in collectSurroundingLoops
directly from the IR.
Interestingly this also results in a couple of isl sets to take a simpler
representation.
llvm-svn: 326664
As part of this cleanup a couple of unnecessary isl::manage(obj.copy()) pattern
are eliminated as well.
We checked for all potential cleanups by scanning for:
"grep -R isl::manage\( lib/ | grep copy"
llvm-svn: 325558
Two or more PHIs mutually using each other directly or indirectly as
incoming value could cause that a PHI WRITE be added before the PHI READ
(i.e. it overwrites the current incoming value with the next incoming
value before it being read).
Fix by ensuring that the PHI WRITE and PHI READ are in the same statement.
This should fix the miscompile of SingleSource/Benchmark/Misc/whetstone
from the test-suite.
llvm-svn: 324934
Splitting basic blocks into multiple statements if there are now
additional scalar dependencies gives more freedom to the scheduler, but
more statements also means higher compile-time complexity. Switch to
finer statement granularity, the additional compile time should be
limited by the number of operations quota.
The regression tests are written for the -polly-stmt-granularity=bb
setting, therefore we add that flag to those tests that break with the
new default. Some of the tests only fail because the statements are
named differently due to a basic block resulting in multiple statements,
but which are removed during simplification of statements without
side-effects. Previous commits tried to reduce this effect, but it is
not completely avoidable.
Differential Revision: https://reviews.llvm.org/D42151
llvm-svn: 324169
Do not add a "_last" suffix to the statement name if there is no (other)
main statement for a basic block. In other words, it becomes the main
statement itself. This further reduces the statement naming difference
between -polly-stmt-granularity=bb and
-polly-stmt-granularity=scalar-indep.
llvm-svn: 324168
Theoretically, a PHI write can be added to any statement that represents
the incoming basic block. We previously always chose the last because
the incoming value's definition is guaranteed to be defined.
With this patch the PHI write is added to the statement that defines the
incoming value. It avoids the requirement for a scalar dependency between
the defining statement and the statement containing the write. As such the
logic for -polly-stmt-granularity=scalar-indep that ensures that there is
such scalar dependencies can be removed.
Differential Revision: https://reviews.llvm.org/D42147
llvm-svn: 323284
The goal is to have -polly-stmt-granularity=bb and
-polly-stmt-granularity=scalar-indep to have the same names if there is
just one statement per basic block.
This fixes a fluke when Polybench's jacobi-2d is optimized differently
depending on the -polly-stmt-granularity option, although both options
create the same SCoP, just with different statement names.
The new naming scheme is:
With -polly-use-llvm-names=0:
Stmt<BBIdx as decimal><Idx within BB as letter>
With -polly-use-llvm-names=1:
Stmt_BBName_<Idx within BB as letter>
The <Idx within BB> suffix is omitted for the main statement of a BB. The
main statement is either the one containing the first store or call
(those cannot be removed by the simplifyer), or if there is no such
instruction, the first. If after simplification there is just a single
statement left, it should be the main statement and have the same names as
with -polly-stmt-granularity=bb.
Differential Revision: https://reviews.llvm.org/D42136
llvm-svn: 322852
This will give control of the statement's name to the caller.
Required to give -polly-stmt-granularity=scalar-indep more control
over the name of the generated statement in a follow-up commit.
llvm-svn: 322851
isl_val_get_num_si crashes on overflow, so don't use it on arbitrary
integers.
Testcase only crashes on platforms where long is 32 bits because of the
signature of isl_val_get_num_si; not sure if it's possible to write a
testcase which crashes if long is 64 bits.
There are a few other places in polly which use isl_val_get_num_si;
they probably need to be fixed as well. I don't think polly uses any
of the other "long" isl APIs in an unsafe manner.
Differential Revision: https://reviews.llvm.org/D42129
llvm-svn: 322766
Summary:
Most changes are mechanical, but in one place I changed the program semantics
by fixing a likely bug:
In `Scop::hasFeasibleRuntimeContext()`, I'm now explicitely handling the
error-case. Before, when the call to `addNonEmptyDomainConstraints()`
returned a null set, this (probably) accidentally worked because
isl_bool_error converts to true. I'm checking for nullptr now.
Reviewers: grosser, Meinersbur, bollu
Reviewed By: Meinersbur
Subscribers: nemanjai, kbarton, pollydev, llvm-commits
Differential Revision: https://reviews.llvm.org/D39971
llvm-svn: 318632
Summary:
There is a potential use-after-free bug in Scop::buildSchedule(Region *,
LoopStackTy &, LoopInfo &). Before, we took a reference to LoopStack.back()
which is a use after free, since back is popped off further below. This didn't
crash before by pure chance, since LoopStack is actually a vector, and the
memory isn't freed upon pop. I turned this into an iterator-based algorithm.
Reviewers: grosser, bollu, Meinersbur
Reviewed By: Meinersbur
Subscribers: llvm-commits, pollydev
Differential Revision: https://reviews.llvm.org/D39979
llvm-svn: 318415
Tobias Grosser