llvm-project/polly/lib/Transform/FlattenSchedule.cpp

107 lines
3.4 KiB
C++

//===------ FlattenSchedule.cpp --------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Try to reduce the number of scatter dimension. Useful to make isl_union_map
// schedules more understandable. This is only intended for debugging and
// unittests, not for production use.
//
//===----------------------------------------------------------------------===//
#include "polly/FlattenSchedule.h"
#include "polly/FlattenAlgo.h"
#include "polly/ScopInfo.h"
#include "polly/ScopPass.h"
#include "polly/Support/ISLOStream.h"
#include "polly/Support/ISLTools.h"
#define DEBUG_TYPE "polly-flatten-schedule"
using namespace polly;
using namespace llvm;
namespace {
/// Print a schedule to @p OS.
///
/// Prints the schedule for each statements on a new line.
void printSchedule(raw_ostream &OS, const isl::union_map &Schedule,
int indent) {
for (isl::map Map : Schedule.get_map_list())
OS.indent(indent) << Map << "\n";
}
/// Flatten the schedule stored in an polly::Scop.
class FlattenSchedule : public ScopPass {
private:
FlattenSchedule(const FlattenSchedule &) = delete;
const FlattenSchedule &operator=(const FlattenSchedule &) = delete;
std::shared_ptr<isl_ctx> IslCtx;
isl::union_map OldSchedule;
public:
static char ID;
explicit FlattenSchedule() : ScopPass(ID) {}
virtual void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequiredTransitive<ScopInfoRegionPass>();
AU.setPreservesAll();
}
virtual bool runOnScop(Scop &S) override {
// Keep a reference to isl_ctx to ensure that it is not freed before we free
// OldSchedule.
IslCtx = S.getSharedIslCtx();
LLVM_DEBUG(dbgs() << "Going to flatten old schedule:\n");
OldSchedule = S.getSchedule();
LLVM_DEBUG(printSchedule(dbgs(), OldSchedule, 2));
auto Domains = S.getDomains();
auto RestrictedOldSchedule = OldSchedule.intersect_domain(Domains);
LLVM_DEBUG(dbgs() << "Old schedule with domains:\n");
LLVM_DEBUG(printSchedule(dbgs(), RestrictedOldSchedule, 2));
auto NewSchedule = flattenSchedule(RestrictedOldSchedule);
LLVM_DEBUG(dbgs() << "Flattened new schedule:\n");
LLVM_DEBUG(printSchedule(dbgs(), NewSchedule, 2));
NewSchedule = NewSchedule.gist_domain(Domains);
LLVM_DEBUG(dbgs() << "Gisted, flattened new schedule:\n");
LLVM_DEBUG(printSchedule(dbgs(), NewSchedule, 2));
S.setSchedule(NewSchedule);
return false;
}
virtual void printScop(raw_ostream &OS, Scop &S) const override {
OS << "Schedule before flattening {\n";
printSchedule(OS, OldSchedule, 4);
OS << "}\n\n";
OS << "Schedule after flattening {\n";
printSchedule(OS, S.getSchedule(), 4);
OS << "}\n";
}
virtual void releaseMemory() override {
OldSchedule = {};
IslCtx.reset();
}
};
char FlattenSchedule::ID;
} // anonymous namespace
Pass *polly::createFlattenSchedulePass() { return new FlattenSchedule(); }
INITIALIZE_PASS_BEGIN(FlattenSchedule, "polly-flatten-schedule",
"Polly - Flatten schedule", false, false)
INITIALIZE_PASS_END(FlattenSchedule, "polly-flatten-schedule",
"Polly - Flatten schedule", false, false)