forked from OSchip/llvm-project
671 lines
24 KiB
C++
671 lines
24 KiB
C++
//===- DependenceInfo.cpp - Calculate dependency information for a Scop. --===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Calculate the data dependency relations for a Scop using ISL.
|
|
//
|
|
// The integer set library (ISL) from Sven, has a integrated dependency analysis
|
|
// to calculate data dependences. This pass takes advantage of this and
|
|
// calculate those dependences a Scop.
|
|
//
|
|
// The dependences in this pass are exact in terms that for a specific read
|
|
// statement instance only the last write statement instance is returned. In
|
|
// case of may writes a set of possible write instances is returned. This
|
|
// analysis will never produce redundant dependences.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
#include "polly/DependenceInfo.h"
|
|
#include "polly/LinkAllPasses.h"
|
|
#include "polly/Options.h"
|
|
#include "polly/ScopInfo.h"
|
|
#include "polly/Support/GICHelper.h"
|
|
#include "llvm/Support/Debug.h"
|
|
|
|
#include <isl/aff.h>
|
|
#include <isl/ctx.h>
|
|
#include <isl/flow.h>
|
|
#include <isl/map.h>
|
|
#include <isl/options.h>
|
|
#include <isl/set.h>
|
|
#include <isl/schedule.h>
|
|
|
|
using namespace polly;
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "polly-dependence"
|
|
|
|
static cl::opt<int> OptComputeOut(
|
|
"polly-dependences-computeout",
|
|
cl::desc("Bound the dependence analysis by a maximal amount of "
|
|
"computational steps (0 means no bound)"),
|
|
cl::Hidden, cl::init(250000), cl::ZeroOrMore, cl::cat(PollyCategory));
|
|
|
|
static cl::opt<bool> LegalityCheckDisabled(
|
|
"disable-polly-legality", cl::desc("Disable polly legality check"),
|
|
cl::Hidden, cl::init(false), cl::ZeroOrMore, cl::cat(PollyCategory));
|
|
|
|
enum AnalysisType { VALUE_BASED_ANALYSIS, MEMORY_BASED_ANALYSIS };
|
|
|
|
static cl::opt<enum AnalysisType> OptAnalysisType(
|
|
"polly-dependences-analysis-type",
|
|
cl::desc("The kind of dependence analysis to use"),
|
|
cl::values(clEnumValN(VALUE_BASED_ANALYSIS, "value-based",
|
|
"Exact dependences without transitive dependences"),
|
|
clEnumValN(MEMORY_BASED_ANALYSIS, "memory-based",
|
|
"Overapproximation of dependences"),
|
|
clEnumValEnd),
|
|
cl::Hidden, cl::init(VALUE_BASED_ANALYSIS), cl::ZeroOrMore,
|
|
cl::cat(PollyCategory));
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// @brief Collect information about the SCoP @p S.
|
|
static void collectInfo(Scop &S, isl_union_map **Read, isl_union_map **Write,
|
|
isl_union_map **MayWrite,
|
|
isl_union_map **AccessSchedule,
|
|
isl_union_map **StmtSchedule) {
|
|
isl_space *Space = S.getParamSpace();
|
|
*Read = isl_union_map_empty(isl_space_copy(Space));
|
|
*Write = isl_union_map_empty(isl_space_copy(Space));
|
|
*MayWrite = isl_union_map_empty(isl_space_copy(Space));
|
|
*AccessSchedule = isl_union_map_empty(isl_space_copy(Space));
|
|
*StmtSchedule = isl_union_map_empty(Space);
|
|
|
|
SmallPtrSet<const Value *, 8> ReductionBaseValues;
|
|
for (ScopStmt *Stmt : S)
|
|
for (MemoryAccess *MA : *Stmt)
|
|
if (MA->isReductionLike())
|
|
ReductionBaseValues.insert(MA->getBaseAddr());
|
|
|
|
for (ScopStmt *Stmt : S) {
|
|
for (MemoryAccess *MA : *Stmt) {
|
|
isl_set *domcp = Stmt->getDomain();
|
|
isl_map *accdom = MA->getAccessRelation();
|
|
|
|
accdom = isl_map_intersect_domain(accdom, domcp);
|
|
|
|
if (ReductionBaseValues.count(MA->getBaseAddr())) {
|
|
// Wrap the access domain and adjust the schedule accordingly.
|
|
//
|
|
// An access domain like
|
|
// Stmt[i0, i1] -> MemAcc_A[i0 + i1]
|
|
// will be transformed into
|
|
// [Stmt[i0, i1] -> MemAcc_A[i0 + i1]] -> MemAcc_A[i0 + i1]
|
|
//
|
|
// The original schedule looks like
|
|
// Stmt[i0, i1] -> [0, i0, 2, i1, 0]
|
|
// but as we transformed the access domain we need the schedule
|
|
// to match the new access domains, thus we need
|
|
// [Stmt[i0, i1] -> MemAcc_A[i0 + i1]] -> [0, i0, 2, i1, 0]
|
|
isl_map *Schedule = Stmt->getSchedule();
|
|
Schedule = isl_map_apply_domain(
|
|
Schedule,
|
|
isl_map_reverse(isl_map_domain_map(isl_map_copy(accdom))));
|
|
accdom = isl_map_range_map(accdom);
|
|
*AccessSchedule = isl_union_map_add_map(*AccessSchedule, Schedule);
|
|
}
|
|
|
|
if (MA->isRead())
|
|
*Read = isl_union_map_add_map(*Read, accdom);
|
|
else
|
|
*Write = isl_union_map_add_map(*Write, accdom);
|
|
}
|
|
*StmtSchedule = isl_union_map_add_map(*StmtSchedule, Stmt->getSchedule());
|
|
}
|
|
|
|
*StmtSchedule =
|
|
isl_union_map_intersect_params(*StmtSchedule, S.getAssumedContext());
|
|
}
|
|
|
|
/// @brief Fix all dimension of @p Zero to 0 and add it to @p user
|
|
static int fixSetToZero(__isl_take isl_set *Zero, void *user) {
|
|
isl_union_set **User = (isl_union_set **)user;
|
|
for (unsigned i = 0; i < isl_set_dim(Zero, isl_dim_set); i++)
|
|
Zero = isl_set_fix_si(Zero, isl_dim_set, i, 0);
|
|
*User = isl_union_set_add_set(*User, Zero);
|
|
return 0;
|
|
}
|
|
|
|
/// @brief Compute the privatization dependences for a given dependency @p Map
|
|
///
|
|
/// Privatization dependences are widened original dependences which originate
|
|
/// or end in a reduction access. To compute them we apply the transitive close
|
|
/// of the reduction dependences (which maps each iteration of a reduction
|
|
/// statement to all following ones) on the RAW/WAR/WAW dependences. The
|
|
/// dependences which start or end at a reduction statement will be extended to
|
|
/// depend on all following reduction statement iterations as well.
|
|
/// Note: "Following" here means according to the reduction dependences.
|
|
///
|
|
/// For the input:
|
|
///
|
|
/// S0: *sum = 0;
|
|
/// for (int i = 0; i < 1024; i++)
|
|
/// S1: *sum += i;
|
|
/// S2: *sum = *sum * 3;
|
|
///
|
|
/// we have the following dependences before we add privatization dependences:
|
|
///
|
|
/// RAW:
|
|
/// { S0[] -> S1[0]; S1[1023] -> S2[] }
|
|
/// WAR:
|
|
/// { }
|
|
/// WAW:
|
|
/// { S0[] -> S1[0]; S1[1024] -> S2[] }
|
|
/// RED:
|
|
/// { S1[i0] -> S1[1 + i0] : i0 >= 0 and i0 <= 1022 }
|
|
///
|
|
/// and afterwards:
|
|
///
|
|
/// RAW:
|
|
/// { S0[] -> S1[i0] : i0 >= 0 and i0 <= 1023;
|
|
/// S1[i0] -> S2[] : i0 >= 0 and i0 <= 1023}
|
|
/// WAR:
|
|
/// { }
|
|
/// WAW:
|
|
/// { S0[] -> S1[i0] : i0 >= 0 and i0 <= 1023;
|
|
/// S1[i0] -> S2[] : i0 >= 0 and i0 <= 1023}
|
|
/// RED:
|
|
/// { S1[i0] -> S1[1 + i0] : i0 >= 0 and i0 <= 1022 }
|
|
///
|
|
/// Note: This function also computes the (reverse) transitive closure of the
|
|
/// reduction dependences.
|
|
void Dependences::addPrivatizationDependences() {
|
|
isl_union_map *PrivRAW, *PrivWAW, *PrivWAR;
|
|
|
|
// The transitive closure might be over approximated, thus could lead to
|
|
// dependency cycles in the privatization dependences. To make sure this
|
|
// will not happen we remove all negative dependences after we computed
|
|
// the transitive closure.
|
|
TC_RED = isl_union_map_transitive_closure(isl_union_map_copy(RED), 0);
|
|
|
|
// FIXME: Apply the current schedule instead of assuming the identity schedule
|
|
// here. The current approach is only valid as long as we compute the
|
|
// dependences only with the initial (identity schedule). Any other
|
|
// schedule could change "the direction of the backward dependences" we
|
|
// want to eliminate here.
|
|
isl_union_set *UDeltas = isl_union_map_deltas(isl_union_map_copy(TC_RED));
|
|
isl_union_set *Universe = isl_union_set_universe(isl_union_set_copy(UDeltas));
|
|
isl_union_set *Zero = isl_union_set_empty(isl_union_set_get_space(Universe));
|
|
isl_union_set_foreach_set(Universe, fixSetToZero, &Zero);
|
|
isl_union_map *NonPositive = isl_union_set_lex_le_union_set(UDeltas, Zero);
|
|
|
|
TC_RED = isl_union_map_subtract(TC_RED, NonPositive);
|
|
|
|
TC_RED = isl_union_map_union(
|
|
TC_RED, isl_union_map_reverse(isl_union_map_copy(TC_RED)));
|
|
TC_RED = isl_union_map_coalesce(TC_RED);
|
|
|
|
isl_union_map **Maps[] = {&RAW, &WAW, &WAR};
|
|
isl_union_map **PrivMaps[] = {&PrivRAW, &PrivWAW, &PrivWAR};
|
|
for (unsigned u = 0; u < 3; u++) {
|
|
isl_union_map **Map = Maps[u], **PrivMap = PrivMaps[u];
|
|
|
|
*PrivMap = isl_union_map_apply_range(isl_union_map_copy(*Map),
|
|
isl_union_map_copy(TC_RED));
|
|
*PrivMap = isl_union_map_union(
|
|
*PrivMap, isl_union_map_apply_range(isl_union_map_copy(TC_RED),
|
|
isl_union_map_copy(*Map)));
|
|
|
|
*Map = isl_union_map_union(*Map, *PrivMap);
|
|
}
|
|
|
|
isl_union_set_free(Universe);
|
|
}
|
|
|
|
void Dependences::calculateDependences(Scop &S) {
|
|
isl_union_map *Read, *Write, *MayWrite, *AccessSchedule, *StmtSchedule,
|
|
*ScheduleMap;
|
|
|
|
DEBUG(dbgs() << "Scop: \n" << S << "\n");
|
|
|
|
collectInfo(S, &Read, &Write, &MayWrite, &AccessSchedule, &StmtSchedule);
|
|
|
|
ScheduleMap =
|
|
isl_union_map_union(AccessSchedule, isl_union_map_copy(StmtSchedule));
|
|
|
|
Read = isl_union_map_coalesce(Read);
|
|
Write = isl_union_map_coalesce(Write);
|
|
MayWrite = isl_union_map_coalesce(MayWrite);
|
|
|
|
long MaxOpsOld = isl_ctx_get_max_operations(S.getIslCtx());
|
|
if (OptComputeOut)
|
|
isl_ctx_set_max_operations(S.getIslCtx(), OptComputeOut);
|
|
isl_options_set_on_error(S.getIslCtx(), ISL_ON_ERROR_CONTINUE);
|
|
|
|
DEBUG(dbgs() << "Read: " << Read << "\n";
|
|
dbgs() << "Write: " << Write << "\n";
|
|
dbgs() << "MayWrite: " << MayWrite << "\n";
|
|
dbgs() << "Schedule: " << ScheduleMap << "\n");
|
|
|
|
RAW = WAW = WAR = RED = nullptr;
|
|
|
|
auto *Schedule = isl_schedule_from_domain(
|
|
isl_union_map_domain(isl_union_map_copy(ScheduleMap)));
|
|
Schedule = isl_schedule_insert_partial_schedule(
|
|
Schedule, isl_multi_union_pw_aff_from_union_map(ScheduleMap));
|
|
|
|
if (OptAnalysisType == VALUE_BASED_ANALYSIS) {
|
|
isl_union_access_info *AI;
|
|
isl_union_flow *Flow;
|
|
|
|
AI = isl_union_access_info_from_sink(isl_union_map_copy(Read));
|
|
AI = isl_union_access_info_set_must_source(AI, isl_union_map_copy(Write));
|
|
AI = isl_union_access_info_set_may_source(AI, isl_union_map_copy(MayWrite));
|
|
AI = isl_union_access_info_set_schedule(AI, isl_schedule_copy(Schedule));
|
|
Flow = isl_union_access_info_compute_flow(AI);
|
|
|
|
RAW = isl_union_flow_get_must_dependence(Flow);
|
|
isl_union_flow_free(Flow);
|
|
|
|
AI = isl_union_access_info_from_sink(isl_union_map_copy(Write));
|
|
AI = isl_union_access_info_set_must_source(AI, isl_union_map_copy(Write));
|
|
AI = isl_union_access_info_set_may_source(AI, isl_union_map_copy(Read));
|
|
AI = isl_union_access_info_set_schedule(AI, Schedule);
|
|
Flow = isl_union_access_info_compute_flow(AI);
|
|
|
|
WAW = isl_union_flow_get_must_dependence(Flow);
|
|
WAR = isl_union_flow_get_may_dependence(Flow);
|
|
|
|
// This subtraction is needed to obtain the same results as were given by
|
|
// isl_union_map_compute_flow. For large sets this may add some compile-time
|
|
// cost. As there does not seem to be a need to distinguish between WAW and
|
|
// WAR, refactoring Polly to only track general non-flow dependences may
|
|
// improve performance.
|
|
WAR = isl_union_map_subtract(WAR, isl_union_map_copy(WAW));
|
|
isl_union_flow_free(Flow);
|
|
} else {
|
|
isl_union_access_info *AI;
|
|
isl_union_flow *Flow;
|
|
|
|
Write = isl_union_map_union(Write, isl_union_map_copy(MayWrite));
|
|
|
|
AI = isl_union_access_info_from_sink(isl_union_map_copy(Read));
|
|
AI = isl_union_access_info_set_may_source(AI, isl_union_map_copy(Write));
|
|
AI = isl_union_access_info_set_schedule(AI, isl_schedule_copy(Schedule));
|
|
Flow = isl_union_access_info_compute_flow(AI);
|
|
|
|
RAW = isl_union_flow_get_may_dependence(Flow);
|
|
isl_union_flow_free(Flow);
|
|
|
|
AI = isl_union_access_info_from_sink(isl_union_map_copy(Write));
|
|
AI = isl_union_access_info_set_may_source(AI, isl_union_map_copy(Read));
|
|
AI = isl_union_access_info_set_schedule(AI, isl_schedule_copy(Schedule));
|
|
Flow = isl_union_access_info_compute_flow(AI);
|
|
|
|
WAR = isl_union_flow_get_may_dependence(Flow);
|
|
isl_union_flow_free(Flow);
|
|
|
|
AI = isl_union_access_info_from_sink(isl_union_map_copy(Write));
|
|
AI = isl_union_access_info_set_may_source(AI, isl_union_map_copy(Write));
|
|
AI = isl_union_access_info_set_schedule(AI, Schedule);
|
|
Flow = isl_union_access_info_compute_flow(AI);
|
|
|
|
WAW = isl_union_flow_get_may_dependence(Flow);
|
|
isl_union_flow_free(Flow);
|
|
}
|
|
|
|
isl_union_map_free(MayWrite);
|
|
isl_union_map_free(Write);
|
|
isl_union_map_free(Read);
|
|
|
|
RAW = isl_union_map_coalesce(RAW);
|
|
WAW = isl_union_map_coalesce(WAW);
|
|
WAR = isl_union_map_coalesce(WAR);
|
|
|
|
if (isl_ctx_last_error(S.getIslCtx()) == isl_error_quota) {
|
|
isl_union_map_free(RAW);
|
|
isl_union_map_free(WAW);
|
|
isl_union_map_free(WAR);
|
|
RAW = WAW = WAR = nullptr;
|
|
isl_ctx_reset_error(S.getIslCtx());
|
|
}
|
|
isl_options_set_on_error(S.getIslCtx(), ISL_ON_ERROR_ABORT);
|
|
isl_ctx_reset_operations(S.getIslCtx());
|
|
isl_ctx_set_max_operations(S.getIslCtx(), MaxOpsOld);
|
|
|
|
isl_union_map *STMT_RAW, *STMT_WAW, *STMT_WAR;
|
|
STMT_RAW = isl_union_map_intersect_domain(
|
|
isl_union_map_copy(RAW),
|
|
isl_union_map_domain(isl_union_map_copy(StmtSchedule)));
|
|
STMT_WAW = isl_union_map_intersect_domain(
|
|
isl_union_map_copy(WAW),
|
|
isl_union_map_domain(isl_union_map_copy(StmtSchedule)));
|
|
STMT_WAR = isl_union_map_intersect_domain(isl_union_map_copy(WAR),
|
|
isl_union_map_domain(StmtSchedule));
|
|
DEBUG({
|
|
dbgs() << "Wrapped Dependences:\n";
|
|
dump();
|
|
dbgs() << "\n";
|
|
});
|
|
|
|
// To handle reduction dependences we proceed as follows:
|
|
// 1) Aggregate all possible reduction dependences, namely all self
|
|
// dependences on reduction like statements.
|
|
// 2) Intersect them with the actual RAW & WAW dependences to the get the
|
|
// actual reduction dependences. This will ensure the load/store memory
|
|
// addresses were __identical__ in the two iterations of the statement.
|
|
// 3) Relax the original RAW and WAW dependences by substracting the actual
|
|
// reduction dependences. Binary reductions (sum += A[i]) cause both, and
|
|
// the same, RAW and WAW dependences.
|
|
// 4) Add the privatization dependences which are widened versions of
|
|
// already present dependences. They model the effect of manual
|
|
// privatization at the outermost possible place (namely after the last
|
|
// write and before the first access to a reduction location).
|
|
|
|
// Step 1)
|
|
RED = isl_union_map_empty(isl_union_map_get_space(RAW));
|
|
for (ScopStmt *Stmt : S) {
|
|
for (MemoryAccess *MA : *Stmt) {
|
|
if (!MA->isReductionLike())
|
|
continue;
|
|
isl_set *AccDomW = isl_map_wrap(MA->getAccessRelation());
|
|
isl_map *Identity =
|
|
isl_map_from_domain_and_range(isl_set_copy(AccDomW), AccDomW);
|
|
RED = isl_union_map_add_map(RED, Identity);
|
|
}
|
|
}
|
|
|
|
// Step 2)
|
|
RED = isl_union_map_intersect(RED, isl_union_map_copy(RAW));
|
|
RED = isl_union_map_intersect(RED, isl_union_map_copy(WAW));
|
|
|
|
if (!isl_union_map_is_empty(RED)) {
|
|
|
|
// Step 3)
|
|
RAW = isl_union_map_subtract(RAW, isl_union_map_copy(RED));
|
|
WAW = isl_union_map_subtract(WAW, isl_union_map_copy(RED));
|
|
|
|
// Step 4)
|
|
addPrivatizationDependences();
|
|
}
|
|
|
|
DEBUG({
|
|
dbgs() << "Final Wrapped Dependences:\n";
|
|
dump();
|
|
dbgs() << "\n";
|
|
});
|
|
|
|
// RED_SIN is used to collect all reduction dependences again after we
|
|
// split them according to the causing memory accesses. The current assumption
|
|
// is that our method of splitting will not have any leftovers. In the end
|
|
// we validate this assumption until we have more confidence in this method.
|
|
isl_union_map *RED_SIN = isl_union_map_empty(isl_union_map_get_space(RAW));
|
|
|
|
// For each reduction like memory access, check if there are reduction
|
|
// dependences with the access relation of the memory access as a domain
|
|
// (wrapped space!). If so these dependences are caused by this memory access.
|
|
// We then move this portion of reduction dependences back to the statement ->
|
|
// statement space and add a mapping from the memory access to these
|
|
// dependences.
|
|
for (ScopStmt *Stmt : S) {
|
|
for (MemoryAccess *MA : *Stmt) {
|
|
if (!MA->isReductionLike())
|
|
continue;
|
|
|
|
isl_set *AccDomW = isl_map_wrap(MA->getAccessRelation());
|
|
isl_union_map *AccRedDepU = isl_union_map_intersect_domain(
|
|
isl_union_map_copy(TC_RED), isl_union_set_from_set(AccDomW));
|
|
if (isl_union_map_is_empty(AccRedDepU) && !isl_union_map_free(AccRedDepU))
|
|
continue;
|
|
|
|
isl_map *AccRedDep = isl_map_from_union_map(AccRedDepU);
|
|
RED_SIN = isl_union_map_add_map(RED_SIN, isl_map_copy(AccRedDep));
|
|
AccRedDep = isl_map_zip(AccRedDep);
|
|
AccRedDep = isl_set_unwrap(isl_map_domain(AccRedDep));
|
|
setReductionDependences(MA, AccRedDep);
|
|
}
|
|
}
|
|
|
|
assert(isl_union_map_is_equal(RED_SIN, TC_RED) &&
|
|
"Intersecting the reduction dependence domain with the wrapped access "
|
|
"relation is not enough, we need to loosen the access relation also");
|
|
isl_union_map_free(RED_SIN);
|
|
|
|
RAW = isl_union_map_zip(RAW);
|
|
WAW = isl_union_map_zip(WAW);
|
|
WAR = isl_union_map_zip(WAR);
|
|
RED = isl_union_map_zip(RED);
|
|
TC_RED = isl_union_map_zip(TC_RED);
|
|
|
|
DEBUG({
|
|
dbgs() << "Zipped Dependences:\n";
|
|
dump();
|
|
dbgs() << "\n";
|
|
});
|
|
|
|
RAW = isl_union_set_unwrap(isl_union_map_domain(RAW));
|
|
WAW = isl_union_set_unwrap(isl_union_map_domain(WAW));
|
|
WAR = isl_union_set_unwrap(isl_union_map_domain(WAR));
|
|
RED = isl_union_set_unwrap(isl_union_map_domain(RED));
|
|
TC_RED = isl_union_set_unwrap(isl_union_map_domain(TC_RED));
|
|
|
|
DEBUG({
|
|
dbgs() << "Unwrapped Dependences:\n";
|
|
dump();
|
|
dbgs() << "\n";
|
|
});
|
|
|
|
RAW = isl_union_map_union(RAW, STMT_RAW);
|
|
WAW = isl_union_map_union(WAW, STMT_WAW);
|
|
WAR = isl_union_map_union(WAR, STMT_WAR);
|
|
|
|
RAW = isl_union_map_coalesce(RAW);
|
|
WAW = isl_union_map_coalesce(WAW);
|
|
WAR = isl_union_map_coalesce(WAR);
|
|
RED = isl_union_map_coalesce(RED);
|
|
TC_RED = isl_union_map_coalesce(TC_RED);
|
|
|
|
DEBUG(dump());
|
|
}
|
|
|
|
bool Dependences::isValidSchedule(Scop &S,
|
|
StatementToIslMapTy *NewSchedule) const {
|
|
if (LegalityCheckDisabled)
|
|
return true;
|
|
|
|
isl_union_map *Dependences = getDependences(TYPE_RAW | TYPE_WAW | TYPE_WAR);
|
|
isl_space *Space = S.getParamSpace();
|
|
isl_union_map *Schedule = isl_union_map_empty(Space);
|
|
|
|
isl_space *ScheduleSpace = nullptr;
|
|
|
|
for (ScopStmt *Stmt : S) {
|
|
isl_map *StmtScat;
|
|
|
|
if (NewSchedule->find(Stmt) == NewSchedule->end())
|
|
StmtScat = Stmt->getSchedule();
|
|
else
|
|
StmtScat = isl_map_copy((*NewSchedule)[Stmt]);
|
|
|
|
if (!ScheduleSpace)
|
|
ScheduleSpace = isl_space_range(isl_map_get_space(StmtScat));
|
|
|
|
Schedule = isl_union_map_add_map(Schedule, StmtScat);
|
|
}
|
|
|
|
Dependences =
|
|
isl_union_map_apply_domain(Dependences, isl_union_map_copy(Schedule));
|
|
Dependences = isl_union_map_apply_range(Dependences, Schedule);
|
|
|
|
isl_set *Zero = isl_set_universe(isl_space_copy(ScheduleSpace));
|
|
for (unsigned i = 0; i < isl_set_dim(Zero, isl_dim_set); i++)
|
|
Zero = isl_set_fix_si(Zero, isl_dim_set, i, 0);
|
|
|
|
isl_union_set *UDeltas = isl_union_map_deltas(Dependences);
|
|
isl_set *Deltas = isl_union_set_extract_set(UDeltas, ScheduleSpace);
|
|
isl_union_set_free(UDeltas);
|
|
|
|
isl_map *NonPositive = isl_set_lex_le_set(Deltas, Zero);
|
|
bool IsValid = isl_map_is_empty(NonPositive);
|
|
isl_map_free(NonPositive);
|
|
|
|
return IsValid;
|
|
}
|
|
|
|
// Check if the current scheduling dimension is parallel.
|
|
//
|
|
// We check for parallelism by verifying that the loop does not carry any
|
|
// dependences.
|
|
//
|
|
// Parallelism test: if the distance is zero in all outer dimensions, then it
|
|
// has to be zero in the current dimension as well.
|
|
//
|
|
// Implementation: first, translate dependences into time space, then force
|
|
// outer dimensions to be equal. If the distance is zero in the current
|
|
// dimension, then the loop is parallel. The distance is zero in the current
|
|
// dimension if it is a subset of a map with equal values for the current
|
|
// dimension.
|
|
bool Dependences::isParallel(isl_union_map *Schedule, isl_union_map *Deps,
|
|
isl_pw_aff **MinDistancePtr) const {
|
|
isl_set *Deltas, *Distance;
|
|
isl_map *ScheduleDeps;
|
|
unsigned Dimension;
|
|
bool IsParallel;
|
|
|
|
Deps = isl_union_map_apply_range(Deps, isl_union_map_copy(Schedule));
|
|
Deps = isl_union_map_apply_domain(Deps, isl_union_map_copy(Schedule));
|
|
|
|
if (isl_union_map_is_empty(Deps)) {
|
|
isl_union_map_free(Deps);
|
|
return true;
|
|
}
|
|
|
|
ScheduleDeps = isl_map_from_union_map(Deps);
|
|
Dimension = isl_map_dim(ScheduleDeps, isl_dim_out) - 1;
|
|
|
|
for (unsigned i = 0; i < Dimension; i++)
|
|
ScheduleDeps = isl_map_equate(ScheduleDeps, isl_dim_out, i, isl_dim_in, i);
|
|
|
|
Deltas = isl_map_deltas(ScheduleDeps);
|
|
Distance = isl_set_universe(isl_set_get_space(Deltas));
|
|
|
|
// [0, ..., 0, +] - All zeros and last dimension larger than zero
|
|
for (unsigned i = 0; i < Dimension; i++)
|
|
Distance = isl_set_fix_si(Distance, isl_dim_set, i, 0);
|
|
|
|
Distance = isl_set_lower_bound_si(Distance, isl_dim_set, Dimension, 1);
|
|
Distance = isl_set_intersect(Distance, Deltas);
|
|
|
|
IsParallel = isl_set_is_empty(Distance);
|
|
if (IsParallel || !MinDistancePtr) {
|
|
isl_set_free(Distance);
|
|
return IsParallel;
|
|
}
|
|
|
|
Distance = isl_set_project_out(Distance, isl_dim_set, 0, Dimension);
|
|
Distance = isl_set_coalesce(Distance);
|
|
|
|
// This last step will compute a expression for the minimal value in the
|
|
// distance polyhedron Distance with regards to the first (outer most)
|
|
// dimension.
|
|
*MinDistancePtr = isl_pw_aff_coalesce(isl_set_dim_min(Distance, 0));
|
|
|
|
return false;
|
|
}
|
|
|
|
static void printDependencyMap(raw_ostream &OS, __isl_keep isl_union_map *DM) {
|
|
if (DM)
|
|
OS << DM << "\n";
|
|
else
|
|
OS << "n/a\n";
|
|
}
|
|
|
|
void Dependences::print(raw_ostream &OS) const {
|
|
OS << "\tRAW dependences:\n\t\t";
|
|
printDependencyMap(OS, RAW);
|
|
OS << "\tWAR dependences:\n\t\t";
|
|
printDependencyMap(OS, WAR);
|
|
OS << "\tWAW dependences:\n\t\t";
|
|
printDependencyMap(OS, WAW);
|
|
OS << "\tReduction dependences:\n\t\t";
|
|
printDependencyMap(OS, RED);
|
|
OS << "\tTransitive closure of reduction dependences:\n\t\t";
|
|
printDependencyMap(OS, TC_RED);
|
|
}
|
|
|
|
void Dependences::dump() const { print(dbgs()); }
|
|
|
|
void Dependences::releaseMemory() {
|
|
isl_union_map_free(RAW);
|
|
isl_union_map_free(WAR);
|
|
isl_union_map_free(WAW);
|
|
isl_union_map_free(RED);
|
|
isl_union_map_free(TC_RED);
|
|
|
|
RED = RAW = WAR = WAW = TC_RED = nullptr;
|
|
|
|
for (auto &ReductionDeps : ReductionDependences)
|
|
isl_map_free(ReductionDeps.second);
|
|
ReductionDependences.clear();
|
|
}
|
|
|
|
isl_union_map *Dependences::getDependences(int Kinds) const {
|
|
assert(hasValidDependences() && "No valid dependences available");
|
|
isl_space *Space = isl_union_map_get_space(RAW);
|
|
isl_union_map *Deps = isl_union_map_empty(Space);
|
|
|
|
if (Kinds & TYPE_RAW)
|
|
Deps = isl_union_map_union(Deps, isl_union_map_copy(RAW));
|
|
|
|
if (Kinds & TYPE_WAR)
|
|
Deps = isl_union_map_union(Deps, isl_union_map_copy(WAR));
|
|
|
|
if (Kinds & TYPE_WAW)
|
|
Deps = isl_union_map_union(Deps, isl_union_map_copy(WAW));
|
|
|
|
if (Kinds & TYPE_RED)
|
|
Deps = isl_union_map_union(Deps, isl_union_map_copy(RED));
|
|
|
|
if (Kinds & TYPE_TC_RED)
|
|
Deps = isl_union_map_union(Deps, isl_union_map_copy(TC_RED));
|
|
|
|
Deps = isl_union_map_coalesce(Deps);
|
|
Deps = isl_union_map_detect_equalities(Deps);
|
|
return Deps;
|
|
}
|
|
|
|
bool Dependences::hasValidDependences() const {
|
|
return (RAW != nullptr) && (WAR != nullptr) && (WAW != nullptr);
|
|
}
|
|
|
|
isl_map *Dependences::getReductionDependences(MemoryAccess *MA) const {
|
|
return isl_map_copy(ReductionDependences.lookup(MA));
|
|
}
|
|
|
|
void Dependences::setReductionDependences(MemoryAccess *MA, isl_map *D) {
|
|
assert(ReductionDependences.count(MA) == 0 &&
|
|
"Reduction dependences set twice!");
|
|
ReductionDependences[MA] = D;
|
|
}
|
|
|
|
void DependenceInfo::recomputeDependences() {
|
|
releaseMemory();
|
|
D.calculateDependences(*S);
|
|
}
|
|
|
|
bool DependenceInfo::runOnScop(Scop &ScopVar) {
|
|
S = &ScopVar;
|
|
recomputeDependences();
|
|
return false;
|
|
}
|
|
|
|
void DependenceInfo::getAnalysisUsage(AnalysisUsage &AU) const {
|
|
ScopPass::getAnalysisUsage(AU);
|
|
}
|
|
|
|
char DependenceInfo::ID = 0;
|
|
|
|
Pass *polly::createDependenceInfoPass() { return new DependenceInfo(); }
|
|
|
|
INITIALIZE_PASS_BEGIN(DependenceInfo, "polly-dependences",
|
|
"Polly - Calculate dependences", false, false);
|
|
INITIALIZE_PASS_DEPENDENCY(ScopInfo);
|
|
INITIALIZE_PASS_END(DependenceInfo, "polly-dependences",
|
|
"Polly - Calculate dependences", false, false)
|