Bug 1915249: Add more nodiscard. a=RyanVM (f284d74c) · Commits · The Tor Project / Applications / Tor Browser

js/src/jit/IonAnalysis.cpp

+32 −23

Original line number	Diff line number	Diff line
		@@ -29,8 +29,9 @@ using MPhiUseIteratorStack =

		// Look for Phi uses with a depth-first search. If any uses are found the stack
		// of MPhi instructions is returned in the \|worklist\| argument.
		static bool DepthFirstSearchUse(MIRGenerator* mir,
		MPhiUseIteratorStack& worklist, MPhi* phi) {
		[[nodiscard]] static bool DepthFirstSearchUse(MIRGenerator* mir,
		MPhiUseIteratorStack& worklist,
		MPhi* phi) {
		// Push a Phi and the next use to iterate over in the worklist.
		auto push = [&worklist](MPhi* phi, MUseIterator use) -> bool {
		phi->setInWorklist();
		@@ -131,8 +132,8 @@ static bool DepthFirstSearchUse(MIRGenerator* mir,
		return true;
		}

		static bool FlagPhiInputsAsImplicitlyUsed(MIRGenerator* mir, MBasicBlock* block,
		MBasicBlock* succ,
		[[nodiscard]] static bool FlagPhiInputsAsImplicitlyUsed(
		MIRGenerator* mir, MBasicBlock* block, MBasicBlock* succ,
		MPhiUseIteratorStack& worklist) {
		// When removing an edge between 2 blocks, we might remove the ability of
		// later phases to figure out that the uses of a Phi should be considered as
		@@ -265,7 +266,7 @@ static MInstructionIterator FindFirstInstructionAfterBail(MBasicBlock* block) {

		// Given an iterator pointing to the first removed instruction, mark
		// the operands of each removed instruction as having implicit uses.
		static bool FlagOperandsAsImplicitlyUsedAfter(
		[[nodiscard]] static bool FlagOperandsAsImplicitlyUsedAfter(
		MIRGenerator* mir, MBasicBlock* block, MInstructionIterator firstRemoved) {
		MOZ_ASSERT(firstRemoved->block() == block);

		@@ -312,7 +313,7 @@ static bool FlagOperandsAsImplicitlyUsedAfter(
		return true;
		}

		static bool FlagEntryResumePointOperands(MIRGenerator* mir,
		[[nodiscard]] static bool FlagEntryResumePointOperands(MIRGenerator* mir,
		MBasicBlock* block) {
		// Flag observable operands of the entry resume point as having implicit uses.
		MResumePoint* rp = block->entryResumePoint();
		@@ -334,7 +335,7 @@ static bool FlagEntryResumePointOperands(MIRGenerator* mir,
		return true;
		}

		static bool FlagAllOperandsAsImplicitlyUsed(MIRGenerator* mir,
		[[nodiscard]] static bool FlagAllOperandsAsImplicitlyUsed(MIRGenerator* mir,
		MBasicBlock* block) {
		return FlagEntryResumePointOperands(mir, block) &&
		FlagOperandsAsImplicitlyUsedAfter(mir, block, block->begin());
		@@ -420,12 +421,16 @@ bool jit::PruneUnusedBranches(MIRGenerator* mir, MIRGraph& graph) {
		if (!block->isMarked()) {
		// If we are removing the block entirely, mark the operands of every
		// instruction as being implicitly used.
		FlagAllOperandsAsImplicitlyUsed(mir, block);
		if (!FlagAllOperandsAsImplicitlyUsed(mir, block)) {
		return false;
		}
		} else if (block->alwaysBails()) {
		// If we are only trimming instructions after a bail, only mark operands
		// of removed instructions.
		MInstructionIterator firstRemoved = FindFirstInstructionAfterBail(block);
		FlagOperandsAsImplicitlyUsedAfter(mir, block, firstRemoved);
		if (!FlagOperandsAsImplicitlyUsedAfter(mir, block, firstRemoved)) {
		return false;
		}
		}
		}

		@@ -503,7 +508,8 @@ bool jit::PruneUnusedBranches(MIRGenerator* mir, MIRGraph& graph) {
		return true;
		}

		static bool SplitCriticalEdgesForBlock(MIRGraph& graph, MBasicBlock* block) {
		[[nodiscard]] static bool SplitCriticalEdgesForBlock(MIRGraph& graph,
		MBasicBlock* block) {
		if (block->numSuccessors() < 2) {
		return true;
		}
		@@ -767,8 +773,8 @@ static bool IsDiamondPattern(MBasicBlock* initialBlock) {
		return true;
		}

		static bool MaybeFoldDiamondConditionBlock(MIRGraph& graph,
		MBasicBlock* initialBlock) {
		[[nodiscard]] static bool MaybeFoldDiamondConditionBlock(
		MIRGraph& graph, MBasicBlock* initialBlock) {
		MOZ_ASSERT(IsDiamondPattern(initialBlock));

		// Optimize the MIR graph to improve the code generated for conditional
		@@ -936,8 +942,8 @@ static bool IsTrianglePattern(MBasicBlock* initialBlock) {
		return false;
		}

		static bool MaybeFoldTriangleConditionBlock(MIRGraph& graph,
		MBasicBlock* initialBlock) {
		[[nodiscard]] static bool MaybeFoldTriangleConditionBlock(
		MIRGraph& graph, MBasicBlock* initialBlock) {
		MOZ_ASSERT(IsTrianglePattern(initialBlock));

		// Optimize the MIR graph to improve the code generated for boolean
		@@ -1089,7 +1095,7 @@ static bool MaybeFoldTriangleConditionBlock(MIRGraph& graph,
		return true;
		}

		static bool MaybeFoldConditionBlock(MIRGraph& graph,
		[[nodiscard]] static bool MaybeFoldConditionBlock(MIRGraph& graph,
		MBasicBlock* initialBlock) {
		if (IsDiamondPattern(initialBlock)) {
		return MaybeFoldDiamondConditionBlock(graph, initialBlock);
		@@ -1100,7 +1106,8 @@ static bool MaybeFoldConditionBlock(MIRGraph& graph,
		return true;
		}

		static bool MaybeFoldTestBlock(MIRGraph& graph, MBasicBlock* initialBlock) {
		[[nodiscard]] static bool MaybeFoldTestBlock(MIRGraph& graph,
		MBasicBlock* initialBlock) {
		// Handle test expressions on more than two inputs. For example
		// \|if ((x > 10) && (y > 20) && (z > 30)) { ... }\|, which results in the below
		// pattern.
		@@ -2752,7 +2759,9 @@ bool jit::RemoveUnmarkedBlocks(MIRGenerator* mir, MIRGraph& graph,
		continue;
		}

		FlagAllOperandsAsImplicitlyUsed(mir, block);
		if (!FlagAllOperandsAsImplicitlyUsed(mir, block)) {
		return false;
		}
		}

		// Find unmarked blocks and remove them.
		@@ -4003,8 +4012,8 @@ bool jit::EliminateRedundantShapeGuards(MIRGraph& graph) {
		return true;
		}

		static bool TryEliminateGCBarriersForAllocation(TempAllocator& alloc,
		MInstruction* allocation) {
		[[nodiscard]] static bool TryEliminateGCBarriersForAllocation(
		TempAllocator& alloc, MInstruction* allocation) {
		MOZ_ASSERT(allocation->type() == MIRType::Object);

		JitSpew(JitSpew_RedundantGCBarriers, "Analyzing allocation %s",