Coverage Report

Created: 2018-12-13 20:48

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/tools/polly/lib/Transform/ZoneAlgo.cpp
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//===------ ZoneAlgo.cpp ----------------------------------------*- C++ -*-===//
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//
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//                     The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// Derive information about array elements between statements ("Zones").
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//
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// The algorithms here work on the scatter space - the image space of the
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// schedule returned by Scop::getSchedule(). We call an element in that space a
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// "timepoint". Timepoints are lexicographically ordered such that we can
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// defined ranges in the scatter space. We use two flavors of such ranges:
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// Timepoint sets and zones. A timepoint set is simply a subset of the scatter
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// space and is directly stored as isl_set.
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//
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// Zones are used to describe the space between timepoints as open sets, i.e.
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// they do not contain the extrema. Using isl rational sets to express these
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// would be overkill. We also cannot store them as the integer timepoints they
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// contain; the (nonempty) zone between 1 and 2 would be empty and
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// indistinguishable from e.g. the zone between 3 and 4. Also, we cannot store
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// the integer set including the extrema; the set ]1,2[ + ]3,4[ could be
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// coalesced to ]1,3[, although we defined the range [2,3] to be not in the set.
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// Instead, we store the "half-open" integer extrema, including the lower bound,
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// but excluding the upper bound. Examples:
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//
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// * The set { [i] : 1 <= i <= 3 } represents the zone ]0,3[ (which contains the
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//   integer points 1 and 2, but not 0 or 3)
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//
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// * { [1] } represents the zone ]0,1[
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//
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// * { [i] : i = 1 or i = 3 } represents the zone ]0,1[ + ]2,3[
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//
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// Therefore, an integer i in the set represents the zone ]i-1,i[, i.e. strictly
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// speaking the integer points never belong to the zone. However, depending an
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// the interpretation, one might want to include them. Part of the
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// interpretation may not be known when the zone is constructed.
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//
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// Reads are assumed to always take place before writes, hence we can think of
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// reads taking place at the beginning of a timepoint and writes at the end.
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//
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// Let's assume that the zone represents the lifetime of a variable. That is,
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// the zone begins with a write that defines the value during its lifetime and
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// ends with the last read of that value. In the following we consider whether a
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// read/write at the beginning/ending of the lifetime zone should be within the
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// zone or outside of it.
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//
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// * A read at the timepoint that starts the live-range loads the previous
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//   value. Hence, exclude the timepoint starting the zone.
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//
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// * A write at the timepoint that starts the live-range is not defined whether
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//   it occurs before or after the write that starts the lifetime. We do not
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//   allow this situation to occur. Hence, we include the timepoint starting the
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//   zone to determine whether they are conflicting.
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//
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// * A read at the timepoint that ends the live-range reads the same variable.
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//   We include the timepoint at the end of the zone to include that read into
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//   the live-range. Doing otherwise would mean that the two reads access
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//   different values, which would mean that the value they read are both alive
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//   at the same time but occupy the same variable.
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//
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// * A write at the timepoint that ends the live-range starts a new live-range.
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//   It must not be included in the live-range of the previous definition.
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//
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// All combinations of reads and writes at the endpoints are possible, but most
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// of the time only the write->read (for instance, a live-range from definition
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// to last use) and read->write (for instance, an unused range from last use to
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// overwrite) and combinations are interesting (half-open ranges). write->write
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// zones might be useful as well in some context to represent
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// output-dependencies.
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//
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// @see convertZoneToTimepoints
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//
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//
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// The code makes use of maps and sets in many different spaces. To not loose
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// track in which space a set or map is expected to be in, variables holding an
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// isl reference are usually annotated in the comments. They roughly follow isl
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// syntax for spaces, but only the tuples, not the dimensions. The tuples have a
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// meaning as follows:
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//
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// * Space[] - An unspecified tuple. Used for function parameters such that the
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//             function caller can use it for anything they like.
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//
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// * Domain[] - A statement instance as returned by ScopStmt::getDomain()
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//     isl_id_get_name: Stmt_<NameOfBasicBlock>
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//     isl_id_get_user: Pointer to ScopStmt
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//
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// * Element[] - An array element as in the range part of
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//               MemoryAccess::getAccessRelation()
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//     isl_id_get_name: MemRef_<NameOfArrayVariable>
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//     isl_id_get_user: Pointer to ScopArrayInfo
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//
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// * Scatter[] - Scatter space or space of timepoints
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//     Has no tuple id
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//
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// * Zone[] - Range between timepoints as described above
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//     Has no tuple id
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//
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// * ValInst[] - An llvm::Value as defined at a specific timepoint.
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//
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//     A ValInst[] itself can be structured as one of:
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//
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//     * [] - An unknown value.
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//         Always zero dimensions
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//         Has no tuple id
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//
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//     * Value[] - An llvm::Value that is read-only in the SCoP, i.e. its
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//                 runtime content does not depend on the timepoint.
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//         Always zero dimensions
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//         isl_id_get_name: Val_<NameOfValue>
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//         isl_id_get_user: A pointer to an llvm::Value
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//
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//     * SCEV[...] - A synthesizable llvm::SCEV Expression.
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//         In contrast to a Value[] is has at least one dimension per
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//         SCEVAddRecExpr in the SCEV.
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//
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//     * [Domain[] -> Value[]] - An llvm::Value that may change during the
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//                               Scop's execution.
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//         The tuple itself has no id, but it wraps a map space holding a
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//         statement instance which defines the llvm::Value as the map's domain
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//         and llvm::Value itself as range.
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//
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// @see makeValInst()
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//
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// An annotation "{ Domain[] -> Scatter[] }" therefore means: A map from a
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// statement instance to a timepoint, aka a schedule. There is only one scatter
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// space, but most of the time multiple statements are processed in one set.
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// This is why most of the time isl_union_map has to be used.
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//
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// The basic algorithm works as follows:
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// At first we verify that the SCoP is compatible with this technique. For
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// instance, two writes cannot write to the same location at the same statement
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// instance because we cannot determine within the polyhedral model which one
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// comes first. Once this was verified, we compute zones at which an array
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// element is unused. This computation can fail if it takes too long. Then the
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// main algorithm is executed. Because every store potentially trails an unused
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// zone, we start at stores. We search for a scalar (MemoryKind::Value or
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// MemoryKind::PHI) that we can map to the array element overwritten by the
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// store, preferably one that is used by the store or at least the ScopStmt.
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// When it does not conflict with the lifetime of the values in the array
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// element, the map is applied and the unused zone updated as it is now used. We
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// continue to try to map scalars to the array element until there are no more
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// candidates to map. The algorithm is greedy in the sense that the first scalar
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// not conflicting will be mapped. Other scalars processed later that could have
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// fit the same unused zone will be rejected. As such the result depends on the
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// processing order.
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//
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//===----------------------------------------------------------------------===//
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#include "polly/ZoneAlgo.h"
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#include "polly/ScopInfo.h"
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#include "polly/Support/GICHelper.h"
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#include "polly/Support/ISLTools.h"
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#include "polly/Support/VirtualInstruction.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/Support/raw_ostream.h"
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#define DEBUG_TYPE "polly-zone"
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STATISTIC(NumIncompatibleArrays, "Number of not zone-analyzable arrays");
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STATISTIC(NumCompatibleArrays, "Number of zone-analyzable arrays");
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STATISTIC(NumRecursivePHIs, "Number of recursive PHIs");
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STATISTIC(NumNormalizablePHIs, "Number of normalizable PHIs");
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STATISTIC(NumPHINormialization, "Number of PHI executed normalizations");
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using namespace polly;
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using namespace llvm;
170
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static isl::union_map computeReachingDefinition(isl::union_map Schedule,
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                                                isl::union_map Writes,
173
152
                                                bool InclDef, bool InclRedef) {
174
152
  return computeReachingWrite(Schedule, Writes, false, InclDef, InclRedef);
175
152
}
176
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/// Compute the reaching definition of a scalar.
178
///
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/// Compared to computeReachingDefinition, there is just one element which is
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/// accessed and therefore only a set if instances that accesses that element is
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/// required.
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///
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/// @param Schedule  { DomainWrite[] -> Scatter[] }
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/// @param Writes    { DomainWrite[] }
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/// @param InclDef   Include the timepoint of the definition to the result.
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/// @param InclRedef Include the timepoint of the overwrite into the result.
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///
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/// @return { Scatter[] -> DomainWrite[] }
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static isl::union_map computeScalarReachingDefinition(isl::union_map Schedule,
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                                                      isl::union_set Writes,
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                                                      bool InclDef,
192
67
                                                      bool InclRedef) {
193
67
  // { DomainWrite[] -> Element[] }
194
67
  isl::union_map Defs = isl::union_map::from_domain(Writes);
195
67
196
67
  // { [Element[] -> Scatter[]] -> DomainWrite[] }
197
67
  auto ReachDefs =
198
67
      computeReachingDefinition(Schedule, Defs, InclDef, InclRedef);
199
67
200
67
  // { Scatter[] -> DomainWrite[] }
201
67
  return ReachDefs.curry().range().unwrap();
202
67
}
203
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/// Compute the reaching definition of a scalar.
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///
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/// This overload accepts only a single writing statement as an isl_map,
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/// consequently the result also is only a single isl_map.
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///
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/// @param Schedule  { DomainWrite[] -> Scatter[] }
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/// @param Writes    { DomainWrite[] }
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/// @param InclDef   Include the timepoint of the definition to the result.
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/// @param InclRedef Include the timepoint of the overwrite into the result.
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///
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/// @return { Scatter[] -> DomainWrite[] }
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static isl::map computeScalarReachingDefinition(isl::union_map Schedule,
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                                                isl::set Writes, bool InclDef,
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67
                                                bool InclRedef) {
218
67
  isl::space DomainSpace = Writes.get_space();
219
67
  isl::space ScatterSpace = getScatterSpace(Schedule);
220
67
221
67
  //  { Scatter[] -> DomainWrite[] }
222
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  isl::union_map UMap = computeScalarReachingDefinition(
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      Schedule, isl::union_set(Writes), InclDef, InclRedef);
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67
225
67
  isl::space ResultSpace = ScatterSpace.map_from_domain_and_range(DomainSpace);
226
67
  return singleton(UMap, ResultSpace);
227
67
}
228
229
642
isl::union_map polly::makeUnknownForDomain(isl::union_set Domain) {
230
642
  return isl::union_map::from_domain(Domain);
231
642
}
232
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/// Create a domain-to-unknown value mapping.
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///
235
/// @see makeUnknownForDomain(isl::union_set)
236
///
237
/// @param Domain { Domain[] }
238
///
239
/// @return { Domain[] -> ValInst[] }
240
16
static isl::map makeUnknownForDomain(isl::set Domain) {
241
16
  return isl::map::from_domain(Domain);
242
16
}
243
244
/// Return whether @p Map maps to an unknown value.
245
///
246
/// @param { [] -> ValInst[] }
247
668
static bool isMapToUnknown(const isl::map &Map) {
248
668
  isl::space Space = Map.get_space().range();
249
668
  return Space.has_tuple_id(isl::dim::set).is_false() &&
250
668
         
Space.is_wrapping().is_false()486
&&
Space.dim(isl::dim::set) == 089
;
251
668
}
252
253
630
isl::union_map polly::filterKnownValInst(const isl::union_map &UMap) {
254
630
  isl::union_map Result = isl::union_map::empty(UMap.get_space());
255
668
  for (isl::map Map : UMap.get_map_list()) {
256
668
    if (!isMapToUnknown(Map))
257
579
      Result = Result.add_map(Map);
258
668
  }
259
630
  return Result;
260
630
}
261
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ZoneAlgorithm::ZoneAlgorithm(const char *PassName, Scop *S, LoopInfo *LI)
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    : PassName(PassName), IslCtx(S->getSharedIslCtx()), S(S), LI(LI),
264
85
      Schedule(S->getSchedule()) {
265
85
  auto Domains = S->getDomains();
266
85
267
85
  Schedule = Schedule.intersect_domain(Domains);
268
85
  ParamSpace = Schedule.get_space();
269
85
  ScatterSpace = getScatterSpace(Schedule);
270
85
}
271
272
/// Check if all stores in @p Stmt store the very same value.
273
///
274
/// This covers a special situation occurring in Polybench's
275
/// covariance/correlation (which is typical for algorithms that cover symmetric
276
/// matrices):
277
///
278
/// for (int i = 0; i < n; i += 1)
279
///   for (int j = 0; j <= i; j += 1) {
280
///     double x = ...;
281
///     C[i][j] = x;
282
///     C[j][i] = x;
283
///   }
284
///
285
/// For i == j, the same value is written twice to the same element.Double
286
/// writes to the same element are not allowed in DeLICM because its algorithm
287
/// does not see which of the writes is effective.But if its the same value
288
/// anyway, it doesn't matter.
289
///
290
/// LLVM passes, however, cannot simplify this because the write is necessary
291
/// for i != j (unless it would add a condition for one of the writes to occur
292
/// only if i != j).
293
///
294
/// TODO: In the future we may want to extent this to make the checks
295
///       specific to different memory locations.
296
5
static bool onlySameValueWrites(ScopStmt *Stmt) {
297
5
  Value *V = nullptr;
298
5
299
16
  for (auto *MA : *Stmt) {
300
16
    if (!MA->isLatestArrayKind() || 
!MA->isMustWrite()10
||
301
16
        
!MA->isOriginalArrayKind()8
)
302
8
      continue;
303
8
304
8
    if (!V) {
305
4
      V = MA->getAccessValue();
306
4
      continue;
307
4
    }
308
4
309
4
    if (V != MA->getAccessValue())
310
2
      return false;
311
4
  }
312
5
  
return true3
;
313
5
}
314
315
/// Is @p InnerLoop nested inside @p OuterLoop?
316
62
static bool isInsideLoop(Loop *OuterLoop, Loop *InnerLoop) {
317
62
  // If OuterLoop is nullptr, we cannot call its contains() method. In this case
318
62
  // OuterLoop represents the 'top level' and therefore contains all loop.
319
62
  return !OuterLoop || 
OuterLoop->contains(InnerLoop)61
;
320
62
}
321
322
void ZoneAlgorithm::collectIncompatibleElts(ScopStmt *Stmt,
323
                                            isl::union_set &IncompatibleElts,
324
337
                                            isl::union_set &AllElts) {
325
337
  auto Stores = makeEmptyUnionMap();
326
337
  auto Loads = makeEmptyUnionMap();
327
337
328
337
  // This assumes that the MemoryKind::Array MemoryAccesses are iterated in
329
337
  // order.
330
674
  for (auto *MA : *Stmt) {
331
674
    if (!MA->isOriginalArrayKind())
332
492
      continue;
333
182
334
182
    isl::map AccRelMap = getAccessRelationFor(MA);
335
182
    isl::union_map AccRel = AccRelMap;
336
182
337
182
    // To avoid solving any ILP problems, always add entire arrays instead of
338
182
    // just the elements that are accessed.
339
182
    auto ArrayElts = isl::set::universe(AccRelMap.get_space().range());
340
182
    AllElts = AllElts.add_set(ArrayElts);
341
182
342
182
    if (MA->isRead()) {
343
58
      // Reject load after store to same location.
344
58
      if (!Stores.is_disjoint(AccRel)) {
345
1
        LLVM_DEBUG(
346
1
            dbgs() << "Load after store of same element in same statement\n");
347
1
        OptimizationRemarkMissed R(PassName, "LoadAfterStore",
348
1
                                   MA->getAccessInstruction());
349
1
        R << "load after store of same element in same statement";
350
1
        R << " (previous stores: " << Stores;
351
1
        R << ", loading: " << AccRel << ")";
352
1
        S->getFunction().getContext().diagnose(R);
353
1
354
1
        IncompatibleElts = IncompatibleElts.add_set(ArrayElts);
355
1
      }
356
58
357
58
      Loads = Loads.unite(AccRel);
358
58
359
58
      continue;
360
58
    }
361
124
362
124
    // In region statements the order is less clear, eg. the load and store
363
124
    // might be in a boxed loop.
364
124
    if (Stmt->isRegionStmt() && 
!Loads.is_disjoint(AccRel)9
) {
365
2
      LLVM_DEBUG(dbgs() << "WRITE in non-affine subregion not supported\n");
366
2
      OptimizationRemarkMissed R(PassName, "StoreInSubregion",
367
2
                                 MA->getAccessInstruction());
368
2
      R << "store is in a non-affine subregion";
369
2
      S->getFunction().getContext().diagnose(R);
370
2
371
2
      IncompatibleElts = IncompatibleElts.add_set(ArrayElts);
372
2
    }
373
124
374
124
    // Do not allow more than one store to the same location.
375
124
    if (!Stores.is_disjoint(AccRel) && 
!onlySameValueWrites(Stmt)5
) {
376
2
      LLVM_DEBUG(dbgs() << "WRITE after WRITE to same element\n");
377
2
      OptimizationRemarkMissed R(PassName, "StoreAfterStore",
378
2
                                 MA->getAccessInstruction());
379
2
      R << "store after store of same element in same statement";
380
2
      R << " (previous stores: " << Stores;
381
2
      R << ", storing: " << AccRel << ")";
382
2
      S->getFunction().getContext().diagnose(R);
383
2
384
2
      IncompatibleElts = IncompatibleElts.add_set(ArrayElts);
385
2
    }
386
124
387
124
    Stores = Stores.unite(AccRel);
388
124
  }
389
337
}
390
391
60
void ZoneAlgorithm::addArrayReadAccess(MemoryAccess *MA) {
392
60
  assert(MA->isLatestArrayKind());
393
60
  assert(MA->isRead());
394
60
  ScopStmt *Stmt = MA->getStatement();
395
60
396
60
  // { DomainRead[] -> Element[] }
397
60
  auto AccRel = intersectRange(getAccessRelationFor(MA), CompatibleElts);
398
60
  AllReads = AllReads.add_map(AccRel);
399
60
400
60
  if (LoadInst *Load = dyn_cast_or_null<LoadInst>(MA->getAccessInstruction())) {
401
58
    // { DomainRead[] -> ValInst[] }
402
58
    isl::map LoadValInst = makeValInst(
403
58
        Load, Stmt, LI->getLoopFor(Load->getParent()), Stmt->isBlockStmt());
404
58
405
58
    // { DomainRead[] -> [Element[] -> DomainRead[]] }
406
58
    isl::map IncludeElement = AccRel.domain_map().curry();
407
58
408
58
    // { [Element[] -> DomainRead[]] -> ValInst[] }
409
58
    isl::map EltLoadValInst = LoadValInst.apply_domain(IncludeElement);
410
58
411
58
    AllReadValInst = AllReadValInst.add_map(EltLoadValInst);
412
58
  }
413
60
}
414
415
isl::union_map ZoneAlgorithm::getWrittenValue(MemoryAccess *MA,
416
124
                                              isl::map AccRel) {
417
124
  if (!MA->isMustWrite())
418
9
    return {};
419
115
420
115
  Value *AccVal = MA->getAccessValue();
421
115
  ScopStmt *Stmt = MA->getStatement();
422
115
  Instruction *AccInst = MA->getAccessInstruction();
423
115
424
115
  // Write a value to a single element.
425
115
  auto L = MA->isOriginalArrayKind() ? LI->getLoopFor(AccInst->getParent())
426
115
                                     : 
Stmt->getSurroundingLoop()0
;
427
115
  if (AccVal &&
428
115
      
AccVal->getType() == MA->getLatestScopArrayInfo()->getElementType()109
&&
429
115
      
AccRel.is_single_valued().is_true()106
)
430
104
    return makeNormalizedValInst(AccVal, Stmt, L);
431
11
432
11
  // memset(_, '0', ) is equivalent to writing the null value to all touched
433
11
  // elements. isMustWrite() ensures that all of an element's bytes are
434
11
  // overwritten.
435
11
  if (auto *Memset = dyn_cast<MemSetInst>(AccInst)) {
436
6
    auto *WrittenConstant = dyn_cast<Constant>(Memset->getValue());
437
6
    Type *Ty = MA->getLatestScopArrayInfo()->getElementType();
438
6
    if (WrittenConstant && WrittenConstant->isZeroValue()) {
439
6
      Constant *Zero = Constant::getNullValue(Ty);
440
6
      return makeNormalizedValInst(Zero, Stmt, L);
441
6
    }
442
5
  }
443
5
444
5
  return {};
445
5
}
446
447
124
void ZoneAlgorithm::addArrayWriteAccess(MemoryAccess *MA) {
448
124
  assert(MA->isLatestArrayKind());
449
124
  assert(MA->isWrite());
450
124
  auto *Stmt = MA->getStatement();
451
124
452
124
  // { Domain[] -> Element[] }
453
124
  isl::map AccRel = intersectRange(getAccessRelationFor(MA), CompatibleElts);
454
124
455
124
  if (MA->isMustWrite())
456
115
    AllMustWrites = AllMustWrites.add_map(AccRel);
457
124
458
124
  if (MA->isMayWrite())
459
9
    AllMayWrites = AllMayWrites.add_map(AccRel);
460
124
461
124
  // { Domain[] -> ValInst[] }
462
124
  isl::union_map WriteValInstance = getWrittenValue(MA, AccRel);
463
124
  if (!WriteValInstance)
464
14
    WriteValInstance = makeUnknownForDomain(Stmt);
465
124
466
124
  // { Domain[] -> [Element[] -> Domain[]] }
467
124
  isl::map IncludeElement = AccRel.domain_map().curry();
468
124
469
124
  // { [Element[] -> DomainWrite[]] -> ValInst[] }
470
124
  isl::union_map EltWriteValInst =
471
124
      WriteValInstance.apply_domain(IncludeElement);
472
124
473
124
  AllWriteValInst = AllWriteValInst.unite(EltWriteValInst);
474
124
}
475
476
/// For an llvm::Value defined in @p DefStmt, compute the RAW dependency for a
477
/// use in every instance of @p UseStmt.
478
///
479
/// @param UseStmt Statement a scalar is used in.
480
/// @param DefStmt Statement a scalar is defined in.
481
///
482
/// @return { DomainUse[] -> DomainDef[] }
483
isl::map ZoneAlgorithm::computeUseToDefFlowDependency(ScopStmt *UseStmt,
484
45
                                                      ScopStmt *DefStmt) {
485
45
  // { DomainUse[] -> Scatter[] }
486
45
  isl::map UseScatter = getScatterFor(UseStmt);
487
45
488
45
  // { Zone[] -> DomainDef[] }
489
45
  isl::map ReachDefZone = getScalarReachingDefinition(DefStmt);
490
45
491
45
  // { Scatter[] -> DomainDef[] }
492
45
  isl::map ReachDefTimepoints =
493
45
      convertZoneToTimepoints(ReachDefZone, isl::dim::in, false, true);
494
45
495
45
  // { DomainUse[] -> DomainDef[] }
496
45
  return UseScatter.apply_range(ReachDefTimepoints);
497
45
}
498
499
/// Return whether @p PHI refers (also transitively through other PHIs) to
500
/// itself.
501
///
502
/// loop:
503
///   %phi1 = phi [0, %preheader], [%phi1, %loop]
504
///   br i1 %c, label %loop, label %exit
505
///
506
/// exit:
507
///   %phi2 = phi [%phi1, %bb]
508
///
509
/// In this example, %phi1 is recursive, but %phi2 is not.
510
6
static bool isRecursivePHI(const PHINode *PHI) {
511
6
  SmallVector<const PHINode *, 8> Worklist;
512
6
  SmallPtrSet<const PHINode *, 8> Visited;
513
6
  Worklist.push_back(PHI);
514
6
515
12
  while (!Worklist.empty()) {
516
7
    const PHINode *Cur = Worklist.pop_back_val();
517
7
518
7
    if (Visited.count(Cur))
519
0
      continue;
520
7
    Visited.insert(Cur);
521
7
522
13
    for (const Use &Incoming : Cur->incoming_values()) {
523
13
      Value *IncomingVal = Incoming.get();
524
13
      auto *IncomingPHI = dyn_cast<PHINode>(IncomingVal);
525
13
      if (!IncomingPHI)
526
11
        continue;
527
2
528
2
      if (IncomingPHI == PHI)
529
1
        return true;
530
1
      Worklist.push_back(IncomingPHI);
531
1
    }
532
7
  }
533
6
  
return false5
;
534
6
}
535
536
39
isl::union_map ZoneAlgorithm::computePerPHI(const ScopArrayInfo *SAI) {
537
39
  // TODO: If the PHI has an incoming block from before the SCoP, it is not
538
39
  // represented in any ScopStmt.
539
39
540
39
  auto *PHI = cast<PHINode>(SAI->getBasePtr());
541
39
  auto It = PerPHIMaps.find(PHI);
542
39
  if (It != PerPHIMaps.end())
543
0
    return It->second;
544
39
545
39
  assert(SAI->isPHIKind());
546
39
547
39
  // { DomainPHIWrite[] -> Scatter[] }
548
39
  isl::union_map PHIWriteScatter = makeEmptyUnionMap();
549
39
550
39
  // Collect all incoming block timepoints.
551
77
  for (MemoryAccess *MA : S->getPHIIncomings(SAI)) {
552
77
    isl::map Scatter = getScatterFor(MA);
553
77
    PHIWriteScatter = PHIWriteScatter.add_map(Scatter);
554
77
  }
555
39
556
39
  // { DomainPHIRead[] -> Scatter[] }
557
39
  isl::map PHIReadScatter = getScatterFor(S->getPHIRead(SAI));
558
39
559
39
  // { DomainPHIRead[] -> Scatter[] }
560
39
  isl::map BeforeRead = beforeScatter(PHIReadScatter, true);
561
39
562
39
  // { Scatter[] }
563
39
  isl::set WriteTimes = singleton(PHIWriteScatter.range(), ScatterSpace);
564
39
565
39
  // { DomainPHIRead[] -> Scatter[] }
566
39
  isl::map PHIWriteTimes = BeforeRead.intersect_range(WriteTimes);
567
39
  isl::map LastPerPHIWrites = PHIWriteTimes.lexmax();
568
39
569
39
  // { DomainPHIRead[] -> DomainPHIWrite[] }
570
39
  isl::union_map Result =
571
39
      isl::union_map(LastPerPHIWrites).apply_range(PHIWriteScatter.reverse());
572
39
  assert(!Result.is_single_valued().is_false());
573
39
  assert(!Result.is_injective().is_false());
574
39
575
39
  PerPHIMaps.insert({PHI, Result});
576
39
  return Result;
577
39
}
578
579
226
isl::union_set ZoneAlgorithm::makeEmptyUnionSet() const {
580
226
  return isl::union_set::empty(ParamSpace);
581
226
}
582
583
1.35k
isl::union_map ZoneAlgorithm::makeEmptyUnionMap() const {
584
1.35k
  return isl::union_map::empty(ParamSpace);
585
1.35k
}
586
587
85
void ZoneAlgorithm::collectCompatibleElts() {
588
85
  // First find all the incompatible elements, then take the complement.
589
85
  // We compile the list of compatible (rather than incompatible) elements so
590
85
  // users can intersect with the list, not requiring a subtract operation. It
591
85
  // also allows us to define a 'universe' of all elements and makes it more
592
85
  // explicit in which array elements can be used.
593
85
  isl::union_set AllElts = makeEmptyUnionSet();
594
85
  isl::union_set IncompatibleElts = makeEmptyUnionSet();
595
85
596
85
  for (auto &Stmt : *S)
597
337
    collectIncompatibleElts(&Stmt, IncompatibleElts, AllElts);
598
85
599
85
  NumIncompatibleArrays += isl_union_set_n_set(IncompatibleElts.get());
600
85
  CompatibleElts = AllElts.subtract(IncompatibleElts);
601
85
  NumCompatibleArrays += isl_union_set_n_set(CompatibleElts.get());
602
85
}
603
604
253
isl::map ZoneAlgorithm::getScatterFor(ScopStmt *Stmt) const {
605
253
  isl::space ResultSpace =
606
253
      Stmt->getDomainSpace().map_from_domain_and_range(ScatterSpace);
607
253
  return Schedule.extract_map(ResultSpace);
608
253
}
609
610
208
isl::map ZoneAlgorithm::getScatterFor(MemoryAccess *MA) const {
611
208
  return getScatterFor(MA->getStatement());
612
208
}
613
614
177
isl::union_map ZoneAlgorithm::getScatterFor(isl::union_set Domain) const {
615
177
  return Schedule.intersect_domain(Domain);
616
177
}
617
618
56
isl::map ZoneAlgorithm::getScatterFor(isl::set Domain) const {
619
56
  auto ResultSpace = Domain.get_space().map_from_domain_and_range(ScatterSpace);
620
56
  auto UDomain = isl::union_set(Domain);
621
56
  auto UResult = getScatterFor(std::move(UDomain));
622
56
  auto Result = singleton(std::move(UResult), std::move(ResultSpace));
623
56
  assert(!Result || Result.domain().is_equal(Domain) == isl_bool_true);
624
56
  return Result;
625
56
}
626
627
1.59k
isl::set ZoneAlgorithm::getDomainFor(ScopStmt *Stmt) const {
628
1.59k
  return Stmt->getDomain().remove_redundancies();
629
1.59k
}
630
631
894
isl::set ZoneAlgorithm::getDomainFor(MemoryAccess *MA) const {
632
894
  return getDomainFor(MA->getStatement());
633
894
}
634
635
464
isl::map ZoneAlgorithm::getAccessRelationFor(MemoryAccess *MA) const {
636
464
  auto Domain = getDomainFor(MA);
637
464
  auto AccRel = MA->getLatestAccessRelation();
638
464
  return AccRel.intersect_domain(Domain);
639
464
}
640
641
isl::map ZoneAlgorithm::getDefToTarget(ScopStmt *DefStmt,
642
211
                                       ScopStmt *TargetStmt) {
643
211
  // No translation required if the definition is already at the target.
644
211
  if (TargetStmt == DefStmt)
645
53
    return isl::map::identity(
646
53
        getDomainFor(TargetStmt).get_space().map_from_set());
647
158
648
158
  isl::map &Result = DefToTargetCache[std::make_pair(TargetStmt, DefStmt)];
649
158
650
158
  // This is a shortcut in case the schedule is still the original and
651
158
  // TargetStmt is in the same or nested inside DefStmt's loop. With the
652
158
  // additional assumption that operand trees do not cross DefStmt's loop
653
158
  // header, then TargetStmt's instance shared coordinates are the same as
654
158
  // DefStmt's coordinates. All TargetStmt instances with this prefix share
655
158
  // the same DefStmt instance.
656
158
  // Model:
657
158
  //
658
158
  //   for (int i < 0; i < N; i+=1) {
659
158
  // DefStmt:
660
158
  //    D = ...;
661
158
  //    for (int j < 0; j < N; j+=1) {
662
158
  // TargetStmt:
663
158
  //      use(D);
664
158
  //    }
665
158
  //  }
666
158
  //
667
158
  // Here, the value used in TargetStmt is defined in the corresponding
668
158
  // DefStmt, i.e.
669
158
  //
670
158
  //   { DefStmt[i] -> TargetStmt[i,j] }
671
158
  //
672
158
  // In practice, this should cover the majority of cases.
673
158
  if (!Result && 
S->isOriginalSchedule()89
&&
674
158
      isInsideLoop(DefStmt->getSurroundingLoop(),
675
62
                   TargetStmt->getSurroundingLoop())) {
676
44
    isl::set DefDomain = getDomainFor(DefStmt);
677
44
    isl::set TargetDomain = getDomainFor(TargetStmt);
678
44
    assert(DefDomain.dim(isl::dim::set) <= TargetDomain.dim(isl::dim::set));
679
44
680
44
    Result = isl::map::from_domain_and_range(DefDomain, TargetDomain);
681
95
    for (unsigned i = 0, DefDims = DefDomain.dim(isl::dim::set); i < DefDims;
682
51
         i += 1)
683
51
      Result = Result.equate(isl::dim::in, i, isl::dim::out, i);
684
44
  }
685
158
686
158
  if (!Result) {
687
45
    // { DomainDef[] -> DomainTarget[] }
688
45
    Result = computeUseToDefFlowDependency(TargetStmt, DefStmt).reverse();
689
45
    simplify(Result);
690
45
  }
691
158
692
158
  return Result;
693
158
}
694
695
101
isl::map ZoneAlgorithm::getScalarReachingDefinition(ScopStmt *Stmt) {
696
101
  auto &Result = ScalarReachDefZone[Stmt];
697
101
  if (Result)
698
34
    return Result;
699
67
700
67
  auto Domain = getDomainFor(Stmt);
701
67
  Result = computeScalarReachingDefinition(Schedule, Domain, false, true);
702
67
  simplify(Result);
703
67
704
67
  return Result;
705
67
}
706
707
0
isl::map ZoneAlgorithm::getScalarReachingDefinition(isl::set DomainDef) {
708
0
  auto DomId = DomainDef.get_tuple_id();
709
0
  auto *Stmt = static_cast<ScopStmt *>(isl_id_get_user(DomId.get()));
710
0
711
0
  auto StmtResult = getScalarReachingDefinition(Stmt);
712
0
713
0
  return StmtResult.intersect_range(DomainDef);
714
0
}
715
716
16
isl::map ZoneAlgorithm::makeUnknownForDomain(ScopStmt *Stmt) const {
717
16
  return ::makeUnknownForDomain(getDomainFor(Stmt));
718
16
}
719
720
364
isl::id ZoneAlgorithm::makeValueId(Value *V) {
721
364
  if (!V)
722
0
    return nullptr;
723
364
724
364
  auto &Id = ValueIds[V];
725
364
  if (Id.is_null()) {
726
198
    auto Name = getIslCompatibleName("Val_", V, ValueIds.size() - 1,
727
198
                                     std::string(), UseInstructionNames);
728
198
    Id = isl::id::alloc(IslCtx.get(), Name.c_str(), V);
729
198
  }
730
364
  return Id;
731
364
}
732
733
364
isl::space ZoneAlgorithm::makeValueSpace(Value *V) {
734
364
  auto Result = ParamSpace.set_from_params();
735
364
  return Result.set_tuple_id(isl::dim::set, makeValueId(V));
736
364
}
737
738
364
isl::set ZoneAlgorithm::makeValueSet(Value *V) {
739
364
  auto Space = makeValueSpace(V);
740
364
  return isl::set::universe(Space);
741
364
}
742
743
isl::map ZoneAlgorithm::makeValInst(Value *Val, ScopStmt *UserStmt, Loop *Scope,
744
369
                                    bool IsCertain) {
745
369
  // If the definition/write is conditional, the value at the location could
746
369
  // be either the written value or the old value. Since we cannot know which
747
369
  // one, consider the value to be unknown.
748
369
  if (!IsCertain)
749
2
    return makeUnknownForDomain(UserStmt);
750
367
751
367
  auto DomainUse = getDomainFor(UserStmt);
752
367
  auto VUse = VirtualUse::create(S, UserStmt, Scope, Val, true);
753
367
  switch (VUse.getKind()) {
754
367
  case VirtualUse::Constant:
755
48
  case VirtualUse::Block:
756
48
  case VirtualUse::Hoisted:
757
48
  case VirtualUse::ReadOnly: {
758
48
    // The definition does not depend on the statement which uses it.
759
48
    auto ValSet = makeValueSet(Val);
760
48
    return isl::map::from_domain_and_range(DomainUse, ValSet);
761
48
  }
762
48
763
48
  case VirtualUse::Synthesizable: {
764
3
    auto *ScevExpr = VUse.getScevExpr();
765
3
    auto UseDomainSpace = DomainUse.get_space();
766
3
767
3
    // Construct the SCEV space.
768
3
    // TODO: Add only the induction variables referenced in SCEVAddRecExpr
769
3
    // expressions, not just all of them.
770
3
    auto ScevId = isl::manage(isl_id_alloc(
771
3
        UseDomainSpace.get_ctx().get(), nullptr, const_cast<SCEV *>(ScevExpr)));
772
3
773
3
    auto ScevSpace = UseDomainSpace.drop_dims(isl::dim::set, 0, 0);
774
3
    ScevSpace = ScevSpace.set_tuple_id(isl::dim::set, ScevId);
775
3
776
3
    // { DomainUse[] -> ScevExpr[] }
777
3
    auto ValInst =
778
3
        isl::map::identity(UseDomainSpace.map_from_domain_and_range(ScevSpace));
779
3
    return ValInst;
780
48
  }
781
48
782
186
  case VirtualUse::Intra: {
783
186
    // Definition and use is in the same statement. We do not need to compute
784
186
    // a reaching definition.
785
186
786
186
    // { llvm::Value }
787
186
    auto ValSet = makeValueSet(Val);
788
186
789
186
    // {  UserDomain[] -> llvm::Value }
790
186
    auto ValInstSet = isl::map::from_domain_and_range(DomainUse, ValSet);
791
186
792
186
    // { UserDomain[] -> [UserDomain[] - >llvm::Value] }
793
186
    auto Result = ValInstSet.domain_map().reverse();
794
186
    simplify(Result);
795
186
    return Result;
796
48
  }
797
48
798
130
  case VirtualUse::Inter: {
799
130
    // The value is defined in a different statement.
800
130
801
130
    auto *Inst = cast<Instruction>(Val);
802
130
    auto *ValStmt = S->getStmtFor(Inst);
803
130
804
130
    // If the llvm::Value is defined in a removed Stmt, we cannot derive its
805
130
    // domain. We could use an arbitrary statement, but this could result in
806
130
    // different ValInst[] for the same llvm::Value.
807
130
    if (!ValStmt)
808
0
      return ::makeUnknownForDomain(DomainUse);
809
130
810
130
    // { DomainUse[] -> DomainDef[] }
811
130
    auto UsedInstance = getDefToTarget(ValStmt, UserStmt).reverse();
812
130
813
130
    // { llvm::Value }
814
130
    auto ValSet = makeValueSet(Val);
815
130
816
130
    // { DomainUse[] -> llvm::Value[] }
817
130
    auto ValInstSet = isl::map::from_domain_and_range(DomainUse, ValSet);
818
130
819
130
    // { DomainUse[] -> [DomainDef[] -> llvm::Value]  }
820
130
    auto Result = UsedInstance.range_product(ValInstSet);
821
130
822
130
    simplify(Result);
823
130
    return Result;
824
130
  }
825
0
  }
826
0
  llvm_unreachable("Unhandled use type");
827
0
}
828
829
/// Remove all computed PHIs out of @p Input and replace by their incoming
830
/// value.
831
///
832
/// @param Input        { [] -> ValInst[] }
833
/// @param ComputedPHIs Set of PHIs that are replaced. Its ValInst must appear
834
///                     on the LHS of @p NormalizeMap.
835
/// @param NormalizeMap { ValInst[] -> ValInst[] }
836
static isl::union_map normalizeValInst(isl::union_map Input,
837
                                       const DenseSet<PHINode *> &ComputedPHIs,
838
144
                                       isl::union_map NormalizeMap) {
839
144
  isl::union_map Result = isl::union_map::empty(Input.get_space());
840
147
  for (isl::map Map : Input.get_map_list()) {
841
147
    isl::space Space = Map.get_space();
842
147
    isl::space RangeSpace = Space.range();
843
147
844
147
    // Instructions within the SCoP are always wrapped. Non-wrapped tuples
845
147
    // are therefore invariant in the SCoP and don't need normalization.
846
147
    if (!RangeSpace.is_wrapping()) {
847
27
      Result = Result.add_map(Map);
848
27
      continue;
849
27
    }
850
120
851
120
    auto *PHI = dyn_cast<PHINode>(static_cast<Value *>(
852
120
        RangeSpace.unwrap().get_tuple_id(isl::dim::out).get_user()));
853
120
854
120
    // If no normalization is necessary, then the ValInst stands for itself.
855
120
    if (!ComputedPHIs.count(PHI)) {
856
106
      Result = Result.add_map(Map);
857
106
      continue;
858
106
    }
859
14
860
14
    // Otherwise, apply the normalization.
861
14
    isl::union_map Mapped = isl::union_map(Map).apply_range(NormalizeMap);
862
14
    Result = Result.unite(Mapped);
863
14
    NumPHINormialization++;
864
14
  }
865
144
  return Result;
866
144
}
867
868
isl::union_map ZoneAlgorithm::makeNormalizedValInst(llvm::Value *Val,
869
                                                    ScopStmt *UserStmt,
870
                                                    llvm::Loop *Scope,
871
134
                                                    bool IsCertain) {
872
134
  isl::map ValInst = makeValInst(Val, UserStmt, Scope, IsCertain);
873
134
  isl::union_map Normalized =
874
134
      normalizeValInst(ValInst, ComputedPHIs, NormalizeMap);
875
134
  return Normalized;
876
134
}
877
878
0
bool ZoneAlgorithm::isCompatibleAccess(MemoryAccess *MA) {
879
0
  if (!MA)
880
0
    return false;
881
0
  if (!MA->isLatestArrayKind())
882
0
    return false;
883
0
  Instruction *AccInst = MA->getAccessInstruction();
884
0
  return isa<StoreInst>(AccInst) || isa<LoadInst>(AccInst);
885
0
}
886
887
6
bool ZoneAlgorithm::isNormalizable(MemoryAccess *MA) {
888
6
  assert(MA->isRead());
889
6
890
6
  // Exclude ExitPHIs, we are assuming that a normalizable PHI has a READ
891
6
  // MemoryAccess.
892
6
  if (!MA->isOriginalPHIKind())
893
0
    return false;
894
6
895
6
  // Exclude recursive PHIs, normalizing them would require a transitive
896
6
  // closure.
897
6
  auto *PHI = cast<PHINode>(MA->getAccessInstruction());
898
6
  if (RecursivePHIs.count(PHI))
899
1
    return false;
900
5
901
5
  // Ensure that each incoming value can be represented by a ValInst[].
902
5
  // We do represent values from statements associated to multiple incoming
903
5
  // value by the PHI itself, but we do not handle this case yet (especially
904
5
  // isNormalized()) when normalizing.
905
5
  const ScopArrayInfo *SAI = MA->getOriginalScopArrayInfo();
906
5
  auto Incomings = S->getPHIIncomings(SAI);
907
9
  for (MemoryAccess *Incoming : Incomings) {
908
9
    if (Incoming->getIncoming().size() != 1)
909
0
      return false;
910
9
  }
911
5
912
5
  return true;
913
5
}
914
915
0
isl::boolean ZoneAlgorithm::isNormalized(isl::map Map) {
916
0
  isl::space Space = Map.get_space();
917
0
  isl::space RangeSpace = Space.range();
918
0
919
0
  isl::boolean IsWrapping = RangeSpace.is_wrapping();
920
0
  if (!IsWrapping.is_true())
921
0
    return !IsWrapping;
922
0
  isl::space Unwrapped = RangeSpace.unwrap();
923
0
924
0
  isl::id OutTupleId = Unwrapped.get_tuple_id(isl::dim::out);
925
0
  if (OutTupleId.is_null())
926
0
    return isl::boolean();
927
0
  auto *PHI = dyn_cast<PHINode>(static_cast<Value *>(OutTupleId.get_user()));
928
0
  if (!PHI)
929
0
    return true;
930
0
931
0
  isl::id InTupleId = Unwrapped.get_tuple_id(isl::dim::in);
932
0
  if (OutTupleId.is_null())
933
0
    return isl::boolean();
934
0
  auto *IncomingStmt = static_cast<ScopStmt *>(InTupleId.get_user());
935
0
  MemoryAccess *PHIRead = IncomingStmt->lookupPHIReadOf(PHI);
936
0
  if (!isNormalizable(PHIRead))
937
0
    return true;
938
0
939
0
  return false;
940
0
}
941
942
0
isl::boolean ZoneAlgorithm::isNormalized(isl::union_map UMap) {
943
0
  isl::boolean Result = true;
944
0
  for (isl::map Map : UMap.get_map_list()) {
945
0
    Result = isNormalized(Map);
946
0
    if (Result.is_true())
947
0
      continue;
948
0
    break;
949
0
  }
950
0
  return Result;
951
0
}
952
953
85
void ZoneAlgorithm::computeCommon() {
954
85
  AllReads = makeEmptyUnionMap();
955
85
  AllMayWrites = makeEmptyUnionMap();
956
85
  AllMustWrites = makeEmptyUnionMap();
957
85
  AllWriteValInst = makeEmptyUnionMap();
958
85
  AllReadValInst = makeEmptyUnionMap();
959
85
960
85
  // Default to empty, i.e. no normalization/replacement is taking place. Call
961
85
  // computeNormalizedPHIs() to initialize.
962
85
  NormalizeMap = makeEmptyUnionMap();
963
85
  ComputedPHIs.clear();
964
85
965
337
  for (auto &Stmt : *S) {
966
674
    for (auto *MA : Stmt) {
967
674
      if (!MA->isLatestArrayKind())
968
490
        continue;
969
184
970
184
      if (MA->isRead())
971
60
        addArrayReadAccess(MA);
972
184
973
184
      if (MA->isWrite())
974
124
        addArrayWriteAccess(MA);
975
184
    }
976
337
  }
977
85
978
85
  // { DomainWrite[] -> Element[] }
979
85
  AllWrites = AllMustWrites.unite(AllMayWrites);
980
85
981
85
  // { [Element[] -> Zone[]] -> DomainWrite[] }
982
85
  WriteReachDefZone =
983
85
      computeReachingDefinition(Schedule, AllWrites, false, true);
984
85
  simplify(WriteReachDefZone);
985
85
}
986
987
4
void ZoneAlgorithm::computeNormalizedPHIs() {
988
4
  // Determine which PHIs can reference themselves. They are excluded from
989
4
  // normalization to avoid problems with transitive closures.
990
13
  for (ScopStmt &Stmt : *S) {
991
38
    for (MemoryAccess *MA : Stmt) {
992
38
      if (!MA->isPHIKind())
993
21
        continue;
994
17
      if (!MA->isRead())
995
11
        continue;
996
6
997
6
      // TODO: Can be more efficient since isRecursivePHI can theoretically
998
6
      // determine recursiveness for multiple values and/or cache results.
999
6
      auto *PHI = cast<PHINode>(MA->getAccessInstruction());
1000
6
      if (isRecursivePHI(PHI)) {
1001
1
        NumRecursivePHIs++;
1002
1
        RecursivePHIs.insert(PHI);
1003
1
      }
1004
6
    }
1005
13
  }
1006
4
1007
4
  // { PHIValInst[] -> IncomingValInst[] }
1008
4
  isl::union_map AllPHIMaps = makeEmptyUnionMap();
1009
4
1010
4
  // Discover new PHIs and try to normalize them.
1011
4
  DenseSet<PHINode *> AllPHIs;
1012
13
  for (ScopStmt &Stmt : *S) {
1013
38
    for (MemoryAccess *MA : Stmt) {
1014
38
      if (!MA->isOriginalPHIKind())
1015
21
        continue;
1016
17
      if (!MA->isRead())
1017
11
        continue;
1018
6
      if (!isNormalizable(MA))
1019
1
        continue;
1020
5
1021
5
      auto *PHI = cast<PHINode>(MA->getAccessInstruction());
1022
5
      const ScopArrayInfo *SAI = MA->getOriginalScopArrayInfo();
1023
5
1024
5
      // { PHIDomain[] -> PHIValInst[] }
1025
5
      isl::map PHIValInst = makeValInst(PHI, &Stmt, Stmt.getSurroundingLoop());
1026
5
1027
5
      // { IncomingDomain[] -> IncomingValInst[] }
1028
5
      isl::union_map IncomingValInsts = makeEmptyUnionMap();
1029
5
1030
5
      // Get all incoming values.
1031
9
      for (MemoryAccess *MA : S->getPHIIncomings(SAI)) {
1032
9
        ScopStmt *IncomingStmt = MA->getStatement();
1033
9
1034
9
        auto Incoming = MA->getIncoming();
1035
9
        assert(Incoming.size() == 1 && "The incoming value must be "
1036
9
                                       "representable by something else than "
1037
9
                                       "the PHI itself");
1038
9
        Value *IncomingVal = Incoming[0].second;
1039
9
1040
9
        // { IncomingDomain[] -> IncomingValInst[] }
1041
9
        isl::map IncomingValInst = makeValInst(
1042
9
            IncomingVal, IncomingStmt, IncomingStmt->getSurroundingLoop());
1043
9
1044
9
        IncomingValInsts = IncomingValInsts.add_map(IncomingValInst);
1045
9
      }
1046
5
1047
5
      // Determine which instance of the PHI statement corresponds to which
1048
5
      // incoming value.
1049
5
      // { PHIDomain[] -> IncomingDomain[] }
1050
5
      isl::union_map PerPHI = computePerPHI(SAI);
1051
5
1052
5
      // { PHIValInst[] -> IncomingValInst[] }
1053
5
      isl::union_map PHIMap =
1054
5
          PerPHI.apply_domain(PHIValInst).apply_range(IncomingValInsts);
1055
5
      assert(!PHIMap.is_single_valued().is_false());
1056
5
1057
5
      // Resolve transitiveness: The incoming value of the newly discovered PHI
1058
5
      // may reference a previously normalized PHI. At the same time, already
1059
5
      // normalized PHIs might be normalized to the new PHI. At the end, none of
1060
5
      // the PHIs may appear on the right-hand-side of the normalization map.
1061
5
      PHIMap = normalizeValInst(PHIMap, AllPHIs, AllPHIMaps);
1062
5
      AllPHIs.insert(PHI);
1063
5
      AllPHIMaps = normalizeValInst(AllPHIMaps, AllPHIs, PHIMap);
1064
5
1065
5
      AllPHIMaps = AllPHIMaps.unite(PHIMap);
1066
5
      NumNormalizablePHIs++;
1067
5
    }
1068
13
  }
1069
4
  simplify(AllPHIMaps);
1070
4
1071
4
  // Apply the normalization.
1072
4
  ComputedPHIs = AllPHIs;
1073
4
  NormalizeMap = AllPHIMaps;
1074
4
1075
4
  assert(!NormalizeMap || isNormalized(NormalizeMap));
1076
4
}
1077
1078
28
void ZoneAlgorithm::printAccesses(llvm::raw_ostream &OS, int Indent) const {
1079
28
  OS.indent(Indent) << "After accesses {\n";
1080
139
  for (auto &Stmt : *S) {
1081
139
    OS.indent(Indent + 4) << Stmt.getBaseName() << "\n";
1082
139
    for (auto *MA : Stmt)
1083
278
      MA->print(OS);
1084
139
  }
1085
28
  OS.indent(Indent) << "}\n";
1086
28
}
1087
1088
85
isl::union_map ZoneAlgorithm::computeKnownFromMustWrites() const {
1089
85
  // { [Element[] -> Zone[]] -> [Element[] -> DomainWrite[]] }
1090
85
  isl::union_map EltReachdDef = distributeDomain(WriteReachDefZone.curry());
1091
85
1092
85
  // { [Element[] -> DomainWrite[]] -> ValInst[] }
1093
85
  isl::union_map AllKnownWriteValInst = filterKnownValInst(AllWriteValInst);
1094
85
1095
85
  // { [Element[] -> Zone[]] -> ValInst[] }
1096
85
  return EltReachdDef.apply_range(AllKnownWriteValInst);
1097
85
}
1098
1099
34
isl::union_map ZoneAlgorithm::computeKnownFromLoad() const {
1100
34
  // { Element[] }
1101
34
  isl::union_set AllAccessedElts = AllReads.range().unite(AllWrites.range());
1102
34
1103
34
  // { Element[] -> Scatter[] }
1104
34
  isl::union_map EltZoneUniverse = isl::union_map::from_domain_and_range(
1105
34
      AllAccessedElts, isl::set::universe(ScatterSpace));
1106
34
1107
34
  // This assumes there are no "holes" in
1108
34
  // isl_union_map_domain(WriteReachDefZone); alternatively, compute the zone
1109
34
  // before the first write or that are not written at all.
1110
34
  // { Element[] -> Scatter[] }
1111
34
  isl::union_set NonReachDef =
1112
34
      EltZoneUniverse.wrap().subtract(WriteReachDefZone.domain());
1113
34
1114
34
  // { [Element[] -> Zone[]] -> ReachDefId[] }
1115
34
  isl::union_map DefZone =
1116
34
      WriteReachDefZone.unite(isl::union_map::from_domain(NonReachDef));
1117
34
1118
34
  // { [Element[] -> Scatter[]] -> Element[] }
1119
34
  isl::union_map EltZoneElt = EltZoneUniverse.domain_map();
1120
34
1121
34
  // { [Element[] -> Zone[]] -> [Element[] -> ReachDefId[]] }
1122
34
  isl::union_map DefZoneEltDefId = EltZoneElt.range_product(DefZone);
1123
34
1124
34
  // { Element[] -> [Zone[] -> ReachDefId[]] }
1125
34
  isl::union_map EltDefZone = DefZone.curry();
1126
34
1127
34
  // { [Element[] -> Zone[] -> [Element[] -> ReachDefId[]] }
1128
34
  isl::union_map EltZoneEltDefid = distributeDomain(EltDefZone);
1129
34
1130
34
  // { [Element[] -> Scatter[]] -> DomainRead[] }
1131
34
  isl::union_map Reads = AllReads.range_product(Schedule).reverse();
1132
34
1133
34
  // { [Element[] -> Scatter[]] -> [Element[] -> DomainRead[]] }
1134
34
  isl::union_map ReadsElt = EltZoneElt.range_product(Reads);
1135
34
1136
34
  // { [Element[] -> Scatter[]] -> ValInst[] }
1137
34
  isl::union_map ScatterKnown = ReadsElt.apply_range(AllReadValInst);
1138
34
1139
34
  // { [Element[] -> ReachDefId[]] -> ValInst[] }
1140
34
  isl::union_map DefidKnown =
1141
34
      DefZoneEltDefId.apply_domain(ScatterKnown).reverse();
1142
34
1143
34
  // { [Element[] -> Zone[]] -> ValInst[] }
1144
34
  return DefZoneEltDefId.apply_range(DefidKnown);
1145
34
}
1146
1147
isl::union_map ZoneAlgorithm::computeKnown(bool FromWrite,
1148
85
                                           bool FromRead) const {
1149
85
  isl::union_map Result = makeEmptyUnionMap();
1150
85
1151
85
  if (FromWrite)
1152
85
    Result = Result.unite(computeKnownFromMustWrites());
1153
85
1154
85
  if (FromRead)
1155
34
    Result = Result.unite(computeKnownFromLoad());
1156
85
1157
85
  simplify(Result);
1158
85
  return Result;
1159
85
}