llvm-project/polly/lib/Support/ISLTools.cpp

518 lines
20 KiB
C++

//===------ ISLTools.cpp ----------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Tools, utilities, helpers and extensions useful in conjunction with the
// Integer Set Library (isl).
//
//===----------------------------------------------------------------------===//
#include "polly/Support/ISLTools.h"
using namespace polly;
namespace {
/// Create a map that shifts one dimension by an offset.
///
/// Example:
/// makeShiftDimAff({ [i0, i1] -> [o0, o1] }, 1, -2)
/// = { [i0, i1] -> [i0, i1 - 1] }
///
/// @param Space The map space of the result. Must have equal number of in- and
/// out-dimensions.
/// @param Pos Position to shift.
/// @param Amount Value added to the shifted dimension.
///
/// @return An isl_multi_aff for the map with this shifted dimension.
isl::multi_aff makeShiftDimAff(isl::space Space, int Pos, int Amount) {
auto Identity = give(isl_multi_aff_identity(Space.take()));
if (Amount == 0)
return Identity;
auto ShiftAff = give(isl_multi_aff_get_aff(Identity.keep(), Pos));
ShiftAff = give(isl_aff_set_constant_si(ShiftAff.take(), Amount));
return give(isl_multi_aff_set_aff(Identity.take(), Pos, ShiftAff.take()));
}
/// Construct a map that swaps two nested tuples.
///
/// @param FromSpace1 { Space1[] }
/// @param FromSpace2 { Space2[] }
///
/// @return { [Space1[] -> Space2[]] -> [Space2[] -> Space1[]] }
isl::basic_map makeTupleSwapBasicMap(isl::space FromSpace1,
isl::space FromSpace2) {
assert(isl_space_is_set(FromSpace1.keep()) != isl_bool_false);
assert(isl_space_is_set(FromSpace2.keep()) != isl_bool_false);
auto Dims1 = isl_space_dim(FromSpace1.keep(), isl_dim_set);
auto Dims2 = isl_space_dim(FromSpace2.keep(), isl_dim_set);
auto FromSpace = give(isl_space_wrap(isl_space_map_from_domain_and_range(
FromSpace1.copy(), FromSpace2.copy())));
auto ToSpace = give(isl_space_wrap(isl_space_map_from_domain_and_range(
FromSpace2.take(), FromSpace1.take())));
auto MapSpace = give(
isl_space_map_from_domain_and_range(FromSpace.take(), ToSpace.take()));
auto Result = give(isl_basic_map_universe(MapSpace.take()));
for (auto i = Dims1 - Dims1; i < Dims1; i += 1) {
Result = give(isl_basic_map_equate(Result.take(), isl_dim_in, i,
isl_dim_out, Dims2 + i));
}
for (auto i = Dims2 - Dims2; i < Dims2; i += 1) {
Result = give(isl_basic_map_equate(Result.take(), isl_dim_in, Dims1 + i,
isl_dim_out, i));
}
return Result;
}
/// Like makeTupleSwapBasicMap(isl::space,isl::space), but returns
/// an isl_map.
isl::map makeTupleSwapMap(isl::space FromSpace1, isl::space FromSpace2) {
auto BMapResult =
makeTupleSwapBasicMap(std::move(FromSpace1), std::move(FromSpace2));
return give(isl_map_from_basic_map(BMapResult.take()));
}
} // anonymous namespace
isl::map polly::beforeScatter(isl::map Map, bool Strict) {
auto RangeSpace = give(isl_space_range(isl_map_get_space(Map.keep())));
auto ScatterRel = give(Strict ? isl_map_lex_gt(RangeSpace.take())
: isl_map_lex_ge(RangeSpace.take()));
return give(isl_map_apply_range(Map.take(), ScatterRel.take()));
}
isl::union_map polly::beforeScatter(isl::union_map UMap, bool Strict) {
auto Result = give(isl_union_map_empty(isl_union_map_get_space(UMap.keep())));
UMap.foreach_map([=, &Result](isl::map Map) -> isl::stat {
auto After = beforeScatter(Map, Strict);
Result = give(isl_union_map_add_map(Result.take(), After.take()));
return isl::stat::ok;
});
return Result;
}
isl::map polly::afterScatter(isl::map Map, bool Strict) {
auto RangeSpace = give(isl_space_range(isl_map_get_space(Map.keep())));
auto ScatterRel = give(Strict ? isl_map_lex_lt(RangeSpace.take())
: isl_map_lex_le(RangeSpace.take()));
return give(isl_map_apply_range(Map.take(), ScatterRel.take()));
}
isl::union_map polly::afterScatter(const isl::union_map &UMap, bool Strict) {
auto Result = give(isl_union_map_empty(isl_union_map_get_space(UMap.keep())));
UMap.foreach_map([=, &Result](isl::map Map) -> isl::stat {
auto After = afterScatter(Map, Strict);
Result = give(isl_union_map_add_map(Result.take(), After.take()));
return isl::stat::ok;
});
return Result;
}
isl::map polly::betweenScatter(isl::map From, isl::map To, bool InclFrom,
bool InclTo) {
auto AfterFrom = afterScatter(From, !InclFrom);
auto BeforeTo = beforeScatter(To, !InclTo);
return give(isl_map_intersect(AfterFrom.take(), BeforeTo.take()));
}
isl::union_map polly::betweenScatter(isl::union_map From, isl::union_map To,
bool InclFrom, bool InclTo) {
auto AfterFrom = afterScatter(From, !InclFrom);
auto BeforeTo = beforeScatter(To, !InclTo);
return give(isl_union_map_intersect(AfterFrom.take(), BeforeTo.take()));
}
isl::map polly::singleton(isl::union_map UMap, isl::space ExpectedSpace) {
if (!UMap)
return nullptr;
if (isl_union_map_n_map(UMap.keep()) == 0)
return give(isl_map_empty(ExpectedSpace.take()));
auto Result = give(isl_map_from_union_map(UMap.take()));
assert(!Result || isl_space_has_equal_tuples(
give(isl_map_get_space(Result.keep())).keep(),
ExpectedSpace.keep()) == isl_bool_true);
return Result;
}
isl::set polly::singleton(isl::union_set USet, isl::space ExpectedSpace) {
if (!USet)
return nullptr;
if (isl_union_set_n_set(USet.keep()) == 0)
return give(isl_set_empty(ExpectedSpace.copy()));
auto Result = give(isl_set_from_union_set(USet.take()));
assert(!Result || isl_space_has_equal_tuples(
give(isl_set_get_space(Result.keep())).keep(),
ExpectedSpace.keep()) == isl_bool_true);
return Result;
}
unsigned polly::getNumScatterDims(const isl::union_map &Schedule) {
unsigned Dims = 0;
Schedule.foreach_map([&Dims](isl::map Map) -> isl::stat {
Dims = std::max(Dims, isl_map_dim(Map.keep(), isl_dim_out));
return isl::stat::ok;
});
return Dims;
}
isl::space polly::getScatterSpace(const isl::union_map &Schedule) {
if (!Schedule)
return nullptr;
auto Dims = getNumScatterDims(Schedule);
auto ScatterSpace =
give(isl_space_set_from_params(isl_union_map_get_space(Schedule.keep())));
return give(isl_space_add_dims(ScatterSpace.take(), isl_dim_set, Dims));
}
isl::union_map polly::makeIdentityMap(const isl::union_set &USet,
bool RestrictDomain) {
auto Result = give(isl_union_map_empty(isl_union_set_get_space(USet.keep())));
USet.foreach_set([=, &Result](isl::set Set) -> isl::stat {
auto IdentityMap = give(isl_map_identity(
isl_space_map_from_set(isl_set_get_space(Set.keep()))));
if (RestrictDomain)
IdentityMap =
give(isl_map_intersect_domain(IdentityMap.take(), Set.take()));
Result = give(isl_union_map_add_map(Result.take(), IdentityMap.take()));
return isl::stat::ok;
});
return Result;
}
isl::map polly::reverseDomain(isl::map Map) {
auto DomSpace =
give(isl_space_unwrap(isl_space_domain(isl_map_get_space(Map.keep()))));
auto Space1 = give(isl_space_domain(DomSpace.copy()));
auto Space2 = give(isl_space_range(DomSpace.take()));
auto Swap = makeTupleSwapMap(std::move(Space1), std::move(Space2));
return give(isl_map_apply_domain(Map.take(), Swap.take()));
}
isl::union_map polly::reverseDomain(const isl::union_map &UMap) {
auto Result = give(isl_union_map_empty(isl_union_map_get_space(UMap.keep())));
UMap.foreach_map([=, &Result](isl::map Map) -> isl::stat {
auto Reversed = reverseDomain(std::move(Map));
Result = give(isl_union_map_add_map(Result.take(), Reversed.take()));
return isl::stat::ok;
});
return Result;
}
isl::set polly::shiftDim(isl::set Set, int Pos, int Amount) {
int NumDims = isl_set_dim(Set.keep(), isl_dim_set);
if (Pos < 0)
Pos = NumDims + Pos;
assert(Pos < NumDims && "Dimension index must be in range");
auto Space = give(isl_set_get_space(Set.keep()));
Space = give(isl_space_map_from_domain_and_range(Space.copy(), Space.copy()));
auto Translator = makeShiftDimAff(std::move(Space), Pos, Amount);
auto TranslatorMap = give(isl_map_from_multi_aff(Translator.take()));
return give(isl_set_apply(Set.take(), TranslatorMap.take()));
}
isl::union_set polly::shiftDim(isl::union_set USet, int Pos, int Amount) {
auto Result = give(isl_union_set_empty(isl_union_set_get_space(USet.keep())));
USet.foreach_set([=, &Result](isl::set Set) -> isl::stat {
auto Shifted = shiftDim(Set, Pos, Amount);
Result = give(isl_union_set_add_set(Result.take(), Shifted.take()));
return isl::stat::ok;
});
return Result;
}
isl::map polly::shiftDim(isl::map Map, isl::dim Dim, int Pos, int Amount) {
int NumDims = Map.dim(Dim);
if (Pos < 0)
Pos = NumDims + Pos;
assert(Pos < NumDims && "Dimension index must be in range");
auto Space = give(isl_map_get_space(Map.keep()));
switch (Dim) {
case isl::dim::in:
Space = std::move(Space).domain();
break;
case isl::dim::out:
Space = give(isl_space_range(Space.take()));
break;
default:
llvm_unreachable("Unsupported value for 'dim'");
}
Space = give(isl_space_map_from_domain_and_range(Space.copy(), Space.copy()));
auto Translator = makeShiftDimAff(std::move(Space), Pos, Amount);
auto TranslatorMap = give(isl_map_from_multi_aff(Translator.take()));
switch (Dim) {
case isl::dim::in:
return Map.apply_domain(TranslatorMap);
case isl::dim::out:
return Map.apply_range(TranslatorMap);
default:
llvm_unreachable("Unsupported value for 'dim'");
}
}
isl::union_map polly::shiftDim(isl::union_map UMap, isl::dim Dim, int Pos,
int Amount) {
auto Result = isl::union_map::empty(UMap.get_space());
UMap.foreach_map([=, &Result](isl::map Map) -> isl::stat {
auto Shifted = shiftDim(Map, Dim, Pos, Amount);
Result = std::move(Result).add_map(Shifted);
return isl::stat::ok;
});
return Result;
}
void polly::simplify(isl::set &Set) {
Set = give(isl_set_compute_divs(Set.take()));
Set = give(isl_set_detect_equalities(Set.take()));
Set = give(isl_set_coalesce(Set.take()));
}
void polly::simplify(isl::union_set &USet) {
USet = give(isl_union_set_compute_divs(USet.take()));
USet = give(isl_union_set_detect_equalities(USet.take()));
USet = give(isl_union_set_coalesce(USet.take()));
}
void polly::simplify(isl::map &Map) {
Map = give(isl_map_compute_divs(Map.take()));
Map = give(isl_map_detect_equalities(Map.take()));
Map = give(isl_map_coalesce(Map.take()));
}
void polly::simplify(isl::union_map &UMap) {
UMap = give(isl_union_map_compute_divs(UMap.take()));
UMap = give(isl_union_map_detect_equalities(UMap.take()));
UMap = give(isl_union_map_coalesce(UMap.take()));
}
isl::union_map polly::computeReachingWrite(isl::union_map Schedule,
isl::union_map Writes, bool Reverse,
bool InclPrevDef, bool InclNextDef) {
// { Scatter[] }
auto ScatterSpace = getScatterSpace(Schedule);
// { ScatterRead[] -> ScatterWrite[] }
isl::map Relation;
if (Reverse)
Relation = give(InclPrevDef ? isl_map_lex_lt(ScatterSpace.take())
: isl_map_lex_le(ScatterSpace.take()));
else
Relation = give(InclNextDef ? isl_map_lex_gt(ScatterSpace.take())
: isl_map_lex_ge(ScatterSpace.take()));
// { ScatterWrite[] -> [ScatterRead[] -> ScatterWrite[]] }
auto RelationMap = give(isl_map_reverse(isl_map_range_map(Relation.take())));
// { Element[] -> ScatterWrite[] }
auto WriteAction =
give(isl_union_map_apply_domain(Schedule.copy(), Writes.take()));
// { ScatterWrite[] -> Element[] }
auto WriteActionRev = give(isl_union_map_reverse(WriteAction.copy()));
// { Element[] -> [ScatterUse[] -> ScatterWrite[]] }
auto DefSchedRelation = give(isl_union_map_apply_domain(
isl_union_map_from_map(RelationMap.take()), WriteActionRev.take()));
// For each element, at every point in time, map to the times of previous
// definitions. { [Element[] -> ScatterRead[]] -> ScatterWrite[] }
auto ReachableWrites = give(isl_union_map_uncurry(DefSchedRelation.take()));
if (Reverse)
ReachableWrites = give(isl_union_map_lexmin(ReachableWrites.copy()));
else
ReachableWrites = give(isl_union_map_lexmax(ReachableWrites.copy()));
// { [Element[] -> ScatterWrite[]] -> ScatterWrite[] }
auto SelfUse = give(isl_union_map_range_map(WriteAction.take()));
if (InclPrevDef && InclNextDef) {
// Add the Def itself to the solution.
ReachableWrites =
give(isl_union_map_union(ReachableWrites.take(), SelfUse.take()));
ReachableWrites = give(isl_union_map_coalesce(ReachableWrites.take()));
} else if (!InclPrevDef && !InclNextDef) {
// Remove Def itself from the solution.
ReachableWrites =
give(isl_union_map_subtract(ReachableWrites.take(), SelfUse.take()));
}
// { [Element[] -> ScatterRead[]] -> Domain[] }
auto ReachableWriteDomain = give(isl_union_map_apply_range(
ReachableWrites.take(), isl_union_map_reverse(Schedule.take())));
return ReachableWriteDomain;
}
isl::union_map
polly::computeArrayUnused(isl::union_map Schedule, isl::union_map Writes,
isl::union_map Reads, bool ReadEltInSameInst,
bool IncludeLastRead, bool IncludeWrite) {
// { Element[] -> Scatter[] }
auto ReadActions =
give(isl_union_map_apply_domain(Schedule.copy(), Reads.take()));
auto WriteActions =
give(isl_union_map_apply_domain(Schedule.copy(), Writes.copy()));
// { [Element[] -> Scatter[] }
auto AfterReads = afterScatter(ReadActions, ReadEltInSameInst);
auto WritesBeforeAnyReads =
give(isl_union_map_subtract(WriteActions.take(), AfterReads.take()));
auto BeforeWritesBeforeAnyReads =
beforeScatter(WritesBeforeAnyReads, !IncludeWrite);
// { [Element[] -> DomainWrite[]] -> Scatter[] }
auto EltDomWrites = give(isl_union_map_apply_range(
isl_union_map_range_map(isl_union_map_reverse(Writes.copy())),
Schedule.copy()));
// { [Element[] -> Scatter[]] -> DomainWrite[] }
auto ReachingOverwrite = computeReachingWrite(
Schedule, Writes, true, ReadEltInSameInst, !ReadEltInSameInst);
// { [Element[] -> Scatter[]] -> DomainWrite[] }
auto ReadsOverwritten = give(isl_union_map_intersect_domain(
ReachingOverwrite.take(), isl_union_map_wrap(ReadActions.take())));
// { [Element[] -> DomainWrite[]] -> Scatter[] }
auto ReadsOverwrittenRotated = give(isl_union_map_reverse(
isl_union_map_curry(reverseDomain(ReadsOverwritten).take())));
auto LastOverwrittenRead =
give(isl_union_map_lexmax(ReadsOverwrittenRotated.take()));
// { [Element[] -> DomainWrite[]] -> Scatter[] }
auto BetweenLastReadOverwrite = betweenScatter(
LastOverwrittenRead, EltDomWrites, IncludeLastRead, IncludeWrite);
return give(isl_union_map_union(
BeforeWritesBeforeAnyReads.take(),
isl_union_map_domain_factor_domain(BetweenLastReadOverwrite.take())));
}
isl::union_set polly::convertZoneToTimepoints(isl::union_set Zone,
bool InclStart, bool InclEnd) {
if (!InclStart && InclEnd)
return Zone;
auto ShiftedZone = shiftDim(Zone, -1, -1);
if (InclStart && !InclEnd)
return ShiftedZone;
else if (!InclStart && !InclEnd)
return give(isl_union_set_intersect(Zone.take(), ShiftedZone.take()));
assert(InclStart && InclEnd);
return give(isl_union_set_union(Zone.take(), ShiftedZone.take()));
}
isl::union_map polly::convertZoneToTimepoints(isl::union_map Zone, isl::dim Dim,
bool InclStart, bool InclEnd) {
if (!InclStart && InclEnd)
return Zone;
auto ShiftedZone = shiftDim(Zone, Dim, -1, -1);
if (InclStart && !InclEnd)
return ShiftedZone;
else if (!InclStart && !InclEnd)
return give(isl_union_map_intersect(Zone.take(), ShiftedZone.take()));
assert(InclStart && InclEnd);
return give(isl_union_map_union(Zone.take(), ShiftedZone.take()));
}
isl::map polly::distributeDomain(isl::map Map) {
// Note that we cannot take Map apart into { Domain[] -> Range1[] } and {
// Domain[] -> Range2[] } and combine again. We would loose any relation
// between Range1[] and Range2[] that is not also a constraint to Domain[].
auto Space = give(isl_map_get_space(Map.keep()));
auto DomainSpace = give(isl_space_domain(Space.copy()));
assert(DomainSpace);
auto DomainDims = isl_space_dim(DomainSpace.keep(), isl_dim_set);
auto RangeSpace = give(isl_space_unwrap(isl_space_range(Space.copy())));
auto Range1Space = give(isl_space_domain(RangeSpace.copy()));
assert(Range1Space);
auto Range1Dims = isl_space_dim(Range1Space.keep(), isl_dim_set);
auto Range2Space = give(isl_space_range(RangeSpace.copy()));
assert(Range2Space);
auto Range2Dims = isl_space_dim(Range2Space.keep(), isl_dim_set);
auto OutputSpace = give(isl_space_map_from_domain_and_range(
isl_space_wrap(isl_space_map_from_domain_and_range(DomainSpace.copy(),
Range1Space.copy())),
isl_space_wrap(isl_space_map_from_domain_and_range(DomainSpace.copy(),
Range2Space.copy()))));
auto Translator =
give(isl_basic_map_universe(isl_space_map_from_domain_and_range(
isl_space_wrap(Space.copy()), isl_space_wrap(OutputSpace.copy()))));
for (unsigned i = 0; i < DomainDims; i += 1) {
Translator = give(
isl_basic_map_equate(Translator.take(), isl_dim_in, i, isl_dim_out, i));
Translator =
give(isl_basic_map_equate(Translator.take(), isl_dim_in, i, isl_dim_out,
DomainDims + Range1Dims + i));
}
for (unsigned i = 0; i < Range1Dims; i += 1) {
Translator =
give(isl_basic_map_equate(Translator.take(), isl_dim_in, DomainDims + i,
isl_dim_out, DomainDims + i));
}
for (unsigned i = 0; i < Range2Dims; i += 1) {
Translator = give(isl_basic_map_equate(
Translator.take(), isl_dim_in, DomainDims + Range1Dims + i, isl_dim_out,
DomainDims + Range1Dims + DomainDims + i));
}
return give(isl_set_unwrap(isl_set_apply(
isl_map_wrap(Map.copy()), isl_map_from_basic_map(Translator.copy()))));
}
isl::union_map polly::distributeDomain(isl::union_map UMap) {
auto Result = give(isl_union_map_empty(isl_union_map_get_space(UMap.keep())));
UMap.foreach_map([=, &Result](isl::map Map) {
auto Distributed = distributeDomain(Map);
Result = give(isl_union_map_add_map(Result.take(), Distributed.copy()));
return isl::stat::ok;
});
return Result;
}
isl::union_map polly::liftDomains(isl::union_map UMap, isl::union_set Factor) {
// { Factor[] -> Factor[] }
auto Factors = makeIdentityMap(std::move(Factor), true);
return std::move(Factors).product(std::move(UMap));
}
isl::union_map polly::applyDomainRange(isl::union_map UMap,
isl::union_map Func) {
// This implementation creates unnecessary cross products of the
// DomainDomain[] and Func. An alternative implementation could reverse
// domain+uncurry,apply Func to what now is the domain, then undo the
// preparing transformation. Another alternative implementation could create a
// translator map for each piece.
// { DomainDomain[] }
auto DomainDomain = UMap.domain().unwrap().domain();
// { [DomainDomain[] -> DomainRange[]] -> [DomainDomain[] -> NewDomainRange[]]
// }
auto LifetedFunc = liftDomains(std::move(Func), DomainDomain);
return std::move(UMap).apply_domain(std::move(LifetedFunc));
}