v8/test/unittests/compiler/coalesced-live-ranges-unittest.cc

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// Copyright 2014 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/compiler/coalesced-live-ranges.h"
#include "test/unittests/test-utils.h"
namespace v8 {
namespace internal {
namespace compiler {
// Utility offering shorthand syntax for building up a range by providing its ID
// and pairs (start, end) specifying intervals. Circumvents current incomplete
// support for C++ features such as instantiation lists, on OS X and Android.
class TestRangeBuilder {
public:
explicit TestRangeBuilder(Zone* zone) : id_(-1), pairs_(), zone_(zone) {}
TestRangeBuilder& Id(int id) {
id_ = id;
return *this;
}
TestRangeBuilder& Add(int start, int end) {
pairs_.push_back({start, end});
return *this;
}
LiveRange* Build(int start, int end) { return Add(start, end).Build(); }
LiveRange* Build() {
[turbofan] Separate LiveRange and TopLevelLiveRange concepts A TopLevelLiveRange is the live range of a virtual register. Through register allocation, it may end up being split in a succession of child live ranges, where data flow is handled through moves from predecessor to successor child. Today, the concepts of "top level" and "child" live ranges are conflated under the LiveRange class. However, a good few APIs pertain solely to TopLevelLiveRanges. This was communicated through comments or DCHECKs - but this makes for poor code comprehensibility and maintainability. For example, the worklist of the register allocator (live_ranges()) needs to only contain TopLevelLiveRanges; spill range concerns are associated only with the top range; phi-ness; certain phases in the allocation pipeline; APIs on LiveRange used for initial construction - before splitting; splintering - these are all responsibilities associated to TopLevelLiveRanges, and not child live ranges. This change separates the concepts. An effect of this change is that child live range allocation need not involve RegisterAllocationData. That's "a good thing" (lower coupling), but it has the side-effect of not having a good way to construct unique identifiers for child live ranges, relative to a given InstructionSequence. LiveRange Id are used primarily for tracing/output-ing, and debugging. I propose a 2-component identifier: a virtual register (vreg) number, uniquely identifying TopLevelLiveRanges; and a relative identifier, which uniquely identifies children of a given TopLevelLiveRange. "0" is reserved for the TopLevel range. The relative identifier does not necessarily indicate order in the child chain, which is no worse than the current state of affairs. I believe this change should make it easier to understand a trace output (because the virtual register number is readily available). I plan to formalize with a small structure the notion of live range id, and consolidate tracing around that, as part of a separate CL. (there are seemingly disparate ways to trace - printf or stream-based APIs - so this seems like an opportune change to consolidate that) Review URL: https://codereview.chromium.org/1311983002 Cr-Commit-Position: refs/heads/master@{#30370}
2015-08-26 05:22:22 +00:00
TopLevelLiveRange* range =
new (zone_) TopLevelLiveRange(id_, MachineType::kRepTagged);
// Traverse the provided interval specifications backwards, because that is
// what LiveRange expects.
for (int i = static_cast<int>(pairs_.size()) - 1; i >= 0; --i) {
Interval pair = pairs_[i];
LifetimePosition start = LifetimePosition::FromInt(pair.first);
LifetimePosition end = LifetimePosition::FromInt(pair.second);
CHECK(start < end);
range->AddUseInterval(start, end, zone_);
}
pairs_.clear();
return range;
}
private:
typedef std::pair<int, int> Interval;
typedef std::vector<Interval> IntervalList;
int id_;
IntervalList pairs_;
Zone* zone_;
};
class CoalescedLiveRangesTest : public TestWithZone {
public:
CoalescedLiveRangesTest() : TestWithZone(), ranges_(zone()) {}
bool HasNoConflicts(const LiveRange* range);
bool ConflictsPreciselyWith(const LiveRange* range, int id);
bool ConflictsPreciselyWith(const LiveRange* range, int id1, int id2);
CoalescedLiveRanges& ranges() { return ranges_; }
const CoalescedLiveRanges& ranges() const { return ranges_; }
bool AllocationsAreValid() const;
void RemoveConflicts(LiveRange* range);
private:
typedef ZoneSet<int> LiveRangeIDs;
bool IsRangeConflictingWith(const LiveRange* range, const LiveRangeIDs& ids);
CoalescedLiveRanges ranges_;
};
bool CoalescedLiveRangesTest::ConflictsPreciselyWith(const LiveRange* range,
int id) {
LiveRangeIDs set(zone());
set.insert(id);
return IsRangeConflictingWith(range, set);
}
bool CoalescedLiveRangesTest::ConflictsPreciselyWith(const LiveRange* range,
int id1, int id2) {
LiveRangeIDs set(zone());
set.insert(id1);
set.insert(id2);
return IsRangeConflictingWith(range, set);
}
bool CoalescedLiveRangesTest::HasNoConflicts(const LiveRange* range) {
LiveRangeIDs set(zone());
return IsRangeConflictingWith(range, set);
}
void CoalescedLiveRangesTest::RemoveConflicts(LiveRange* range) {
auto conflicts = ranges().GetConflicts(range);
LiveRangeIDs seen(zone());
for (auto c = conflicts.Current(); c != nullptr;
c = conflicts.RemoveCurrentAndGetNext()) {
[turbofan] Separate LiveRange and TopLevelLiveRange concepts A TopLevelLiveRange is the live range of a virtual register. Through register allocation, it may end up being split in a succession of child live ranges, where data flow is handled through moves from predecessor to successor child. Today, the concepts of "top level" and "child" live ranges are conflated under the LiveRange class. However, a good few APIs pertain solely to TopLevelLiveRanges. This was communicated through comments or DCHECKs - but this makes for poor code comprehensibility and maintainability. For example, the worklist of the register allocator (live_ranges()) needs to only contain TopLevelLiveRanges; spill range concerns are associated only with the top range; phi-ness; certain phases in the allocation pipeline; APIs on LiveRange used for initial construction - before splitting; splintering - these are all responsibilities associated to TopLevelLiveRanges, and not child live ranges. This change separates the concepts. An effect of this change is that child live range allocation need not involve RegisterAllocationData. That's "a good thing" (lower coupling), but it has the side-effect of not having a good way to construct unique identifiers for child live ranges, relative to a given InstructionSequence. LiveRange Id are used primarily for tracing/output-ing, and debugging. I propose a 2-component identifier: a virtual register (vreg) number, uniquely identifying TopLevelLiveRanges; and a relative identifier, which uniquely identifies children of a given TopLevelLiveRange. "0" is reserved for the TopLevel range. The relative identifier does not necessarily indicate order in the child chain, which is no worse than the current state of affairs. I believe this change should make it easier to understand a trace output (because the virtual register number is readily available). I plan to formalize with a small structure the notion of live range id, and consolidate tracing around that, as part of a separate CL. (there are seemingly disparate ways to trace - printf or stream-based APIs - so this seems like an opportune change to consolidate that) Review URL: https://codereview.chromium.org/1311983002 Cr-Commit-Position: refs/heads/master@{#30370}
2015-08-26 05:22:22 +00:00
int id = c->TopLevel()->vreg();
EXPECT_FALSE(seen.count(id) > 0);
seen.insert(c->TopLevel()->vreg());
}
}
bool CoalescedLiveRangesTest::AllocationsAreValid() const {
return ranges().VerifyAllocationsAreValidForTesting();
}
bool CoalescedLiveRangesTest::IsRangeConflictingWith(const LiveRange* range,
const LiveRangeIDs& ids) {
LiveRangeIDs found_ids(zone());
auto conflicts = ranges().GetConflicts(range);
for (auto conflict = conflicts.Current(); conflict != nullptr;
conflict = conflicts.GetNext()) {
[turbofan] Separate LiveRange and TopLevelLiveRange concepts A TopLevelLiveRange is the live range of a virtual register. Through register allocation, it may end up being split in a succession of child live ranges, where data flow is handled through moves from predecessor to successor child. Today, the concepts of "top level" and "child" live ranges are conflated under the LiveRange class. However, a good few APIs pertain solely to TopLevelLiveRanges. This was communicated through comments or DCHECKs - but this makes for poor code comprehensibility and maintainability. For example, the worklist of the register allocator (live_ranges()) needs to only contain TopLevelLiveRanges; spill range concerns are associated only with the top range; phi-ness; certain phases in the allocation pipeline; APIs on LiveRange used for initial construction - before splitting; splintering - these are all responsibilities associated to TopLevelLiveRanges, and not child live ranges. This change separates the concepts. An effect of this change is that child live range allocation need not involve RegisterAllocationData. That's "a good thing" (lower coupling), but it has the side-effect of not having a good way to construct unique identifiers for child live ranges, relative to a given InstructionSequence. LiveRange Id are used primarily for tracing/output-ing, and debugging. I propose a 2-component identifier: a virtual register (vreg) number, uniquely identifying TopLevelLiveRanges; and a relative identifier, which uniquely identifies children of a given TopLevelLiveRange. "0" is reserved for the TopLevel range. The relative identifier does not necessarily indicate order in the child chain, which is no worse than the current state of affairs. I believe this change should make it easier to understand a trace output (because the virtual register number is readily available). I plan to formalize with a small structure the notion of live range id, and consolidate tracing around that, as part of a separate CL. (there are seemingly disparate ways to trace - printf or stream-based APIs - so this seems like an opportune change to consolidate that) Review URL: https://codereview.chromium.org/1311983002 Cr-Commit-Position: refs/heads/master@{#30370}
2015-08-26 05:22:22 +00:00
found_ids.insert(conflict->TopLevel()->vreg());
}
return found_ids == ids;
}
TEST_F(CoalescedLiveRangesTest, VisitEmptyAllocations) {
LiveRange* range = TestRangeBuilder(zone()).Id(1).Build(1, 5);
ASSERT_TRUE(ranges().empty());
ASSERT_TRUE(AllocationsAreValid());
ASSERT_TRUE(HasNoConflicts(range));
}
TEST_F(CoalescedLiveRangesTest, CandidateBeforeAfterAllocations) {
LiveRange* range = TestRangeBuilder(zone()).Id(1).Build(5, 6);
ranges().AllocateRange(range);
ASSERT_FALSE(ranges().empty());
ASSERT_TRUE(AllocationsAreValid());
LiveRange* query = TestRangeBuilder(zone()).Id(2).Build(1, 2);
ASSERT_TRUE(HasNoConflicts(query));
query = TestRangeBuilder(zone()).Id(3).Build(1, 5);
ASSERT_TRUE(HasNoConflicts(query));
}
TEST_F(CoalescedLiveRangesTest, CandidateBeforeAfterManyAllocations) {
LiveRange* range =
TestRangeBuilder(zone()).Id(1).Add(5, 7).Add(10, 12).Build();
ranges().AllocateRange(range);
ASSERT_FALSE(ranges().empty());
ASSERT_TRUE(AllocationsAreValid());
LiveRange* query =
TestRangeBuilder(zone()).Id(2).Add(1, 2).Add(13, 15).Build();
ASSERT_TRUE(HasNoConflicts(query));
query = TestRangeBuilder(zone()).Id(3).Add(1, 5).Add(12, 15).Build();
ASSERT_TRUE(HasNoConflicts(query));
}
TEST_F(CoalescedLiveRangesTest, SelfConflictsPreciselyWithSelf) {
LiveRange* range = TestRangeBuilder(zone()).Id(1).Build(1, 5);
ranges().AllocateRange(range);
ASSERT_FALSE(ranges().empty());
ASSERT_TRUE(AllocationsAreValid());
ASSERT_TRUE(ConflictsPreciselyWith(range, 1));
range = TestRangeBuilder(zone()).Id(2).Build(8, 10);
ranges().AllocateRange(range);
ASSERT_TRUE(ConflictsPreciselyWith(range, 2));
}
TEST_F(CoalescedLiveRangesTest, QueryStartsBeforeConflict) {
LiveRange* range = TestRangeBuilder(zone()).Id(1).Build(2, 5);
ranges().AllocateRange(range);
LiveRange* query = TestRangeBuilder(zone()).Id(2).Build(1, 3);
ASSERT_TRUE(ConflictsPreciselyWith(query, 1));
range = TestRangeBuilder(zone()).Id(3).Build(8, 10);
ranges().AllocateRange(range);
query = TestRangeBuilder(zone()).Id(4).Build(6, 9);
ASSERT_TRUE(ConflictsPreciselyWith(query, 3));
}
TEST_F(CoalescedLiveRangesTest, QueryStartsInConflict) {
LiveRange* range = TestRangeBuilder(zone()).Id(1).Build(2, 5);
ranges().AllocateRange(range);
LiveRange* query = TestRangeBuilder(zone()).Id(2).Build(3, 6);
ASSERT_TRUE(ConflictsPreciselyWith(query, 1));
range = TestRangeBuilder(zone()).Id(3).Build(8, 10);
ranges().AllocateRange(range);
query = TestRangeBuilder(zone()).Id(4).Build(9, 11);
ASSERT_TRUE(ConflictsPreciselyWith(query, 3));
}
TEST_F(CoalescedLiveRangesTest, QueryContainedInConflict) {
LiveRange* range = TestRangeBuilder(zone()).Id(1).Build(1, 5);
ranges().AllocateRange(range);
LiveRange* query = TestRangeBuilder(zone()).Id(2).Build(2, 3);
ASSERT_TRUE(ConflictsPreciselyWith(query, 1));
}
TEST_F(CoalescedLiveRangesTest, QueryContainsConflict) {
LiveRange* range = TestRangeBuilder(zone()).Id(1).Build(2, 3);
ranges().AllocateRange(range);
LiveRange* query = TestRangeBuilder(zone()).Id(2).Build(1, 5);
ASSERT_TRUE(ConflictsPreciselyWith(query, 1));
}
TEST_F(CoalescedLiveRangesTest, QueryCoversManyIntervalsSameRange) {
LiveRange* range =
TestRangeBuilder(zone()).Id(1).Add(1, 5).Add(7, 9).Add(20, 25).Build();
ranges().AllocateRange(range);
LiveRange* query = TestRangeBuilder(zone()).Id(2).Build(2, 8);
ASSERT_TRUE(ConflictsPreciselyWith(query, 1));
}
TEST_F(CoalescedLiveRangesTest, QueryCoversManyIntervalsDifferentRanges) {
LiveRange* range =
TestRangeBuilder(zone()).Id(1).Add(1, 5).Add(20, 25).Build();
ranges().AllocateRange(range);
range = TestRangeBuilder(zone()).Id(2).Build(7, 10);
ranges().AllocateRange(range);
LiveRange* query = TestRangeBuilder(zone()).Id(3).Build(2, 22);
ASSERT_TRUE(ConflictsPreciselyWith(query, 1, 2));
}
TEST_F(CoalescedLiveRangesTest, QueryFitsInGaps) {
LiveRange* range =
TestRangeBuilder(zone()).Id(1).Add(1, 5).Add(10, 15).Add(20, 25).Build();
ranges().AllocateRange(range);
LiveRange* query =
TestRangeBuilder(zone()).Id(3).Add(5, 10).Add(16, 19).Add(27, 30).Build();
ASSERT_TRUE(HasNoConflicts(query));
}
TEST_F(CoalescedLiveRangesTest, DeleteConflictBefore) {
LiveRange* range = TestRangeBuilder(zone()).Id(1).Add(1, 4).Add(5, 6).Build();
ranges().AllocateRange(range);
range = TestRangeBuilder(zone()).Id(2).Build(40, 50);
ranges().AllocateRange(range);
LiveRange* query = TestRangeBuilder(zone()).Id(3).Build(3, 7);
RemoveConflicts(query);
query = TestRangeBuilder(zone()).Id(4).Build(0, 60);
ASSERT_TRUE(ConflictsPreciselyWith(query, 2));
}
TEST_F(CoalescedLiveRangesTest, DeleteConflictAfter) {
LiveRange* range = TestRangeBuilder(zone()).Id(1).Build(1, 5);
ranges().AllocateRange(range);
range = TestRangeBuilder(zone()).Id(2).Add(40, 50).Add(60, 70).Build();
ranges().AllocateRange(range);
LiveRange* query = TestRangeBuilder(zone()).Id(3).Build(45, 60);
RemoveConflicts(query);
query = TestRangeBuilder(zone()).Id(4).Build(0, 60);
ASSERT_TRUE(ConflictsPreciselyWith(query, 1));
}
TEST_F(CoalescedLiveRangesTest, DeleteConflictStraddle) {
LiveRange* range =
TestRangeBuilder(zone()).Id(1).Add(1, 5).Add(10, 20).Build();
ranges().AllocateRange(range);
range = TestRangeBuilder(zone()).Id(2).Build(40, 50);
ranges().AllocateRange(range);
LiveRange* query = TestRangeBuilder(zone()).Id(3).Build(4, 15);
RemoveConflicts(query);
query = TestRangeBuilder(zone()).Id(4).Build(0, 60);
ASSERT_TRUE(ConflictsPreciselyWith(query, 2));
}
TEST_F(CoalescedLiveRangesTest, DeleteConflictManyOverlapsBefore) {
LiveRange* range =
TestRangeBuilder(zone()).Id(1).Add(1, 5).Add(6, 10).Add(10, 20).Build();
ranges().AllocateRange(range);
range = TestRangeBuilder(zone()).Id(2).Build(40, 50);
ranges().AllocateRange(range);
LiveRange* query = TestRangeBuilder(zone()).Id(3).Build(4, 15);
RemoveConflicts(query);
query = TestRangeBuilder(zone()).Id(4).Build(0, 60);
ASSERT_TRUE(ConflictsPreciselyWith(query, 2));
}
TEST_F(CoalescedLiveRangesTest, DeleteWhenConflictRepeatsAfterNonConflict) {
LiveRange* range =
TestRangeBuilder(zone()).Id(1).Add(1, 5).Add(6, 10).Add(20, 30).Build();
ranges().AllocateRange(range);
range = TestRangeBuilder(zone()).Id(2).Build(12, 15);
ranges().AllocateRange(range);
LiveRange* query =
TestRangeBuilder(zone()).Id(3).Add(1, 8).Add(22, 25).Build();
RemoveConflicts(query);
query = TestRangeBuilder(zone()).Id(4).Build(0, 60);
ASSERT_TRUE(ConflictsPreciselyWith(query, 2));
}
} // namespace compiler
} // namespace internal
} // namespace v8