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[semantic-arc] Move main optimize loop of SemanticARCOptVisitor into its own file.
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-119
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-119
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‎lib/SILOptimizer/SemanticARC/CMakeLists.txt

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Original file line numberDiff line numberDiff line change
@@ -6,4 +6,5 @@ target_sources(swiftSILOptimizer PRIVATE
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CopyValueOpts.cpp
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OwnedToGuaranteedPhiOpt.cpp
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Context.cpp
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SemanticARCOptVisitor.cpp
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)

‎lib/SILOptimizer/SemanticARC/SemanticARCOptVisitor.cpp

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//===--- SemanticARCOptVisitor.cpp ----------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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///
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/// \file
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///
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/// Implementation of the main optimize loop of the ARC visitor peephole
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/// optimizer.
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///
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//===----------------------------------------------------------------------===//
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#include "SemanticARCOptVisitor.h"
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#include "swift/SIL/DebugUtils.h"
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using namespace swift;
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using namespace swift::semanticarc;
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bool SemanticARCOptVisitor::optimize() {
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bool madeChange = false;
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// First process the worklist until we reach a fixed point.
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madeChange |= processWorklist();
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{
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// If we made a change, set that we assume we are at fixed point and then
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// re-run the worklist so that we can
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// properly seeded the ARC peephole map.
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ctx.assumingAtFixedPoint = true;
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SWIFT_DEFER { ctx.assumingAtFixedPoint = false; };
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// Add everything in visitedSinceLastMutation to the worklist so we
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// recompute our fixed point.
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drainVisitedSinceLastMutationIntoWorklist();
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// Then re-run the worklist. We shouldn't modify anything since we are at a
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// fixed point and are just using this to seed the
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// joinedOwnedIntroducerToConsumedOperands after we have finished changing
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// things. If we did change something, we did something weird, so assert!
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bool madeAdditionalChanges = processWorklist();
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(void)madeAdditionalChanges;
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assert(!madeAdditionalChanges && "Should be at the fixed point");
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}
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return madeChange;
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}
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bool SemanticARCOptVisitor::processWorklist() {
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// NOTE: The madeChange here is not strictly necessary since we only have
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// items added to the worklist today if we have already made /some/ sort of
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// change. That being said, I think there is a low cost to including this here
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// and makes the algorithm more correct, visually and in the face of potential
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// refactoring.
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bool madeChange = false;
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while (!worklist.empty()) {
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// Pop the last element off the list. If we were returned None, we blotted
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// this element, so skip it.
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SILValue next = worklist.pop_back_val().getValueOr(SILValue());
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if (!next)
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continue;
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// First check if this is a value that we have visited since the last time
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// we erased an instruction. If we have visited it, skip it. Every time we
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// modify something, we should be deleting an instruction, so we have not
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// found any further information.
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if (!visitedSinceLastMutation.insert(next).second) {
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continue;
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}
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// First check if this is an instruction that is trivially dead. This can
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// occur if we eliminate rr traffic resulting in dead projections and the
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// like.
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//
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// If we delete, we first add all of our deleted instructions operands to
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// the worklist and then remove all results (since we are going to delete
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// the instruction).
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if (auto *defInst = next->getDefiningInstruction()) {
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if (isInstructionTriviallyDead(defInst)) {
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assert(!ctx.assumingAtFixedPoint &&
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"Assumed was at fixed point and recomputing state?!");
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deleteAllDebugUses(defInst);
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eraseInstruction(defInst);
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madeChange = true;
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ctx.verify();
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continue;
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}
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}
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// Otherwise, if we have a single value instruction (to be expanded later
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// perhaps), try to visit that value recursively.
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if (auto *svi = dyn_cast<SingleValueInstruction>(next)) {
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bool madeSingleChange = visit(svi);
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assert((!madeSingleChange || !ctx.assumingAtFixedPoint) &&
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"Assumed was at fixed point and modified state?!");
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madeChange |= madeSingleChange;
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if (madeSingleChange) {
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ctx.verify();
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}
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continue;
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}
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}
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return madeChange;
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}

‎lib/SILOptimizer/SemanticARC/SemanticARCOpts.cpp

Lines changed: 2 additions & 119 deletions
Original file line numberDiff line numberDiff line change
@@ -12,131 +12,14 @@
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#define DEBUG_TYPE "sil-semantic-arc-opts"
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#include "OwnershipLiveRange.h"
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#include "OwnershipPhiOperand.h"
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#include "SemanticARCOptVisitor.h"
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#include "Transforms.h"
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#include "swift/Basic/LLVM.h"
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#include "swift/Basic/BlotSetVector.h"
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#include "swift/Basic/FrozenMultiMap.h"
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#include "swift/Basic/MultiMapCache.h"
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#include "swift/Basic/STLExtras.h"
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#include "swift/SIL/BasicBlockUtils.h"
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#include "swift/SIL/DebugUtils.h"
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#include "swift/SIL/LinearLifetimeChecker.h"
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#include "swift/SIL/MemAccessUtils.h"
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#include "swift/SIL/OwnershipUtils.h"
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#include "swift/SIL/Projection.h"
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#include "swift/SIL/SILArgument.h"
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#include "swift/SIL/SILBuilder.h"
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#include "swift/SIL/SILInstruction.h"
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#include "swift/SIL/SILVisitor.h"
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#include "swift/SILOptimizer/Analysis/PostOrderAnalysis.h"
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#include "swift/SILOptimizer/PassManager/Passes.h"
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#include "swift/SILOptimizer/PassManager/Transforms.h"
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#include "swift/SILOptimizer/Utils/InstOptUtils.h"
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#include "swift/SILOptimizer/Utils/ValueLifetime.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/Statistic.h"
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using namespace swift;
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using namespace swift::semanticarc;
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//===----------------------------------------------------------------------===//
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// Implementation
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//===----------------------------------------------------------------------===//
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bool SemanticARCOptVisitor::optimize() {
53-
bool madeChange = false;
54-
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// First process the worklist until we reach a fixed point.
56-
madeChange |= processWorklist();
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{
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// If we made a change, set that we assume we are at fixed point and then
60-
// re-run the worklist so that we can
61-
// properly seeded the ARC peephole map.
62-
ctx.assumingAtFixedPoint = true;
63-
SWIFT_DEFER { ctx.assumingAtFixedPoint = false; };
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// Add everything in visitedSinceLastMutation to the worklist so we
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// recompute our fixed point.
67-
drainVisitedSinceLastMutationIntoWorklist();
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69-
// Then re-run the worklist. We shouldn't modify anything since we are at a
70-
// fixed point and are just using this to seed the
71-
// joinedOwnedIntroducerToConsumedOperands after we have finished changing
72-
// things. If we did change something, we did something weird, so assert!
73-
bool madeAdditionalChanges = processWorklist();
74-
(void)madeAdditionalChanges;
75-
assert(!madeAdditionalChanges && "Should be at the fixed point");
76-
}
77-
78-
return madeChange;
79-
}
80-
81-
bool SemanticARCOptVisitor::processWorklist() {
82-
// NOTE: The madeChange here is not strictly necessary since we only have
83-
// items added to the worklist today if we have already made /some/ sort of
84-
// change. That being said, I think there is a low cost to including this here
85-
// and makes the algorithm more correct, visually and in the face of potential
86-
// refactoring.
87-
bool madeChange = false;
88-
89-
while (!worklist.empty()) {
90-
// Pop the last element off the list. If we were returned None, we blotted
91-
// this element, so skip it.
92-
SILValue next = worklist.pop_back_val().getValueOr(SILValue());
93-
if (!next)
94-
continue;
95-
96-
// First check if this is a value that we have visited since the last time
97-
// we erased an instruction. If we have visited it, skip it. Every time we
98-
// modify something, we should be deleting an instruction, so we have not
99-
// found any further information.
100-
if (!visitedSinceLastMutation.insert(next).second) {
101-
continue;
102-
}
103-
104-
// First check if this is an instruction that is trivially dead. This can
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// occur if we eliminate rr traffic resulting in dead projections and the
106-
// like.
107-
//
108-
// If we delete, we first add all of our deleted instructions operands to
109-
// the worklist and then remove all results (since we are going to delete
110-
// the instruction).
111-
if (auto *defInst = next->getDefiningInstruction()) {
112-
if (isInstructionTriviallyDead(defInst)) {
113-
assert(!ctx.assumingAtFixedPoint &&
114-
"Assumed was at fixed point and recomputing state?!");
115-
deleteAllDebugUses(defInst);
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eraseInstruction(defInst);
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madeChange = true;
118-
ctx.verify();
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continue;
120-
}
121-
}
122-
123-
// Otherwise, if we have a single value instruction (to be expanded later
124-
// perhaps), try to visit that value recursively.
125-
if (auto *svi = dyn_cast<SingleValueInstruction>(next)) {
126-
bool madeSingleChange = visit(svi);
127-
assert((!madeSingleChange || !ctx.assumingAtFixedPoint) &&
128-
"Assumed was at fixed point and modified state?!");
129-
madeChange |= madeSingleChange;
130-
if (madeSingleChange) {
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ctx.verify();
132-
}
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continue;
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}
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}
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137-
return madeChange;
138-
}
139-
14023
//===----------------------------------------------------------------------===//
14124
// Top Level Entrypoint
14225
//===----------------------------------------------------------------------===//
@@ -179,7 +62,7 @@ struct SemanticARCOpts : SILFunctionTransform {
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}
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18164
// Then process the worklist, performing peepholes.
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bool madeChange = visitor.optimize();
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bool eliminatedARCInst = visitor.optimize();
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18467
// Now that we have seeded the map of phis to incoming values that could be
18568
// converted to guaranteed, ignoring the phi, try convert those phis to be
@@ -191,7 +74,7 @@ struct SemanticARCOpts : SILFunctionTransform {
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}
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19376
// Otherwise, we only deleted instructions and did not touch phis.
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if (madeChange)
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if (eliminatedARCInst)
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invalidateAnalysis(SILAnalysis::InvalidationKind::Instructions);
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}
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};

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