removal of unused functionality and some follow-on simplifications

src/Stmt.cc

@@ -52,7 +52,6 @@ const char* stmt_name(StmtTag t)
 		"check-any-length",
 		"compiled-C++",
 		"ZAM",
-		"ZAM-resumption",
 		"null",
 		"assert",
 	};

src/StmtEnums.h

@@ -31,7 +31,6 @@ enum StmtTag
 	STMT_CHECK_ANY_LEN, // internal reduced statement
 	STMT_CPP, // compiled C++
 	STMT_ZAM, // a ZAM function body
-	STMT_ZAM_RESUMPTION, // resumes ZAM execution for "when" statements
 	STMT_NULL,
 	STMT_ASSERT,
 #define NUM_STMTS (int(STMT_ASSERT) + 1)

src/script_opt/ScriptOpt.h

@@ -138,7 +138,6 @@ public:
 	std::shared_ptr<ProfileFunc> ProfilePtr() const { return pf; }
 
 	void SetBody(StmtPtr new_body) { body = std::move(new_body); }
-	// void SetProfile(std::shared_ptr<ProfileFunc> _pf);
 	void SetProfile(std::shared_ptr<ProfileFunc> _pf) { pf = std::move(_pf); }
 
 	// The following provide a way of marking FuncInfo's as

src/script_opt/ZAM/AM-Opt.cc

@@ -927,47 +927,6 @@ const ZInstI* ZAMCompiler::EndOfLoop(const ZInstI* inst, int depth) const
 	return insts1[i];
 	}
 
-bool ZAMCompiler::VarIsAssigned(int slot) const
-	{
-	for ( auto& inst : insts1 )
-		if ( inst->live && VarIsAssigned(slot, inst) )
-			return true;
-
-	return false;
-	}
-
-bool ZAMCompiler::VarIsAssigned(int slot, const ZInstI* i) const
-	{
-	// Special-case for table iterators, which assign to a bunch
-	// of variables but they're not immediately visible in the
-	// instruction layout.
-	if ( i->op == OP_NEXT_TABLE_ITER_VAL_VAR_VVV || i->op == OP_NEXT_TABLE_ITER_VV )
-		{
-		auto& iter_vars = i->aux->loop_vars;
-		for ( auto v : iter_vars )
-			if ( v == slot )
-				return true;
-
-		if ( i->op != OP_NEXT_TABLE_ITER_VAL_VAR_VVV )
-			return false;
-
-		// Otherwise fall through, since that flavor of iterate
-		// *does* also assign to slot 1.
-		}
-
-	if ( i->op == OP_NEXT_VECTOR_ITER_VAL_VAR_VVVV && i->v2 == slot )
-		return true;
-
-	if ( i->op_type == OP_VV_FRAME )
-		// We don't want to consider these as assigning to the
-		// variable, since the point of this method is to figure
-		// out which variables don't need storing to the frame
-		// because their internal value is never modified.
-		return false;
-
-	return i->AssignsToSlot1() && i->v1 == slot;
-	}
-
 bool ZAMCompiler::VarIsUsed(int slot) const
 	{
 	for ( auto& inst : insts1 )

src/script_opt/ZAM/Compile.h

@@ -459,14 +459,6 @@ private:
 	const ZInstI* BeginningOfLoop(const ZInstI* inst, int depth) const;
 	const ZInstI* EndOfLoop(const ZInstI* inst, int depth) const;
 
-	// True if any statement other than a frame sync assigns to the
-	// given slot.
-	bool VarIsAssigned(int slot) const;
-
-	// True if the given statement assigns to the given slot, and
-	// it's not a frame sync.
-	bool VarIsAssigned(int slot, const ZInstI* i) const;
-
 	// True if any statement other than a frame sync uses the given slot.
 	bool VarIsUsed(int slot) const;
 

src/script_opt/ZAM/Driver.cc

@@ -33,20 +33,9 @@ void ZAMCompiler::Init()
 	{
 	InitGlobals();
 	InitArgs();
+	InitCaptures();
 	InitLocals();
 
-#if 0
-	// Complain about unused aggregates ... but not if we're inlining,
-	// as that can lead to optimizations where they wind up being unused
-	// but the original logic for using them was sound.
-	if ( ! analysis_options.inliner )
-		for ( auto a : pf->Inits() )
-			{
-			if ( pf->Locals().find(a) == pf->Locals().end() )
-				reporter->Warning("%s unused", a->Name());
-			}
-#endif
-
 	TrackMemoryManagement();
 
 	non_recursive = non_recursive_funcs.count(func) > 0;
@@ -216,11 +205,6 @@ StmtPtr ZAMCompiler::CompileBody()
 	// Could erase insts1 here to recover memory, but it's handy
 	// for debugging.
 
-#if 0
-	if ( non_recursive )
-		func->UseStaticFrame();
-#endif
-
 	auto zb = make_intrusive<ZBody>(func->Name(), this);
 	zb->SetInsts(insts2);
 

src/script_opt/ZAM/Expr.cc

@@ -1109,19 +1109,6 @@ const ZAMStmt ZAMCompiler::DoCall(const CallExpr* c, const NameExpr* n)
 			z.func = func_id->GetVal()->AsFunc();
 		}
 
-	if ( n )
-		{
-		auto id = n->Id();
-		if ( id->IsGlobal() )
-			{
-			AddInst(z);
-			auto global_slot = global_id_to_info[id];
-			z = ZInstI(OP_STORE_GLOBAL_V, global_slot);
-			z.op_type = OP_V_I1;
-			z.t = globalsI[global_slot].id->GetType();
-			}
-		}
-
 	return AddInst(z);
 	}
 

src/script_opt/ZAM/ZBody.cc

@@ -193,10 +193,10 @@ ZBody::~ZBody()
 
 void ZBody::SetInsts(vector<ZInst*>& _insts)
 	{
-	ninst = _insts.size();
+	end_pc = _insts.size();
-	auto insts_copy = new ZInst[ninst];
+	auto insts_copy = new ZInst[end_pc];
 
-	for ( auto i = 0U; i < ninst; ++i )
+	for ( auto i = 0U; i < end_pc; ++i )
 		insts_copy[i] = *_insts[i];
 
 	insts = insts_copy;
@@ -206,10 +206,10 @@ void ZBody::SetInsts(vector<ZInst*>& _insts)
 
 void ZBody::SetInsts(vector<ZInstI*>& instsI)
 	{
-	ninst = instsI.size();
+	end_pc = instsI.size();
-	auto insts_copy = new ZInst[ninst];
+	auto insts_copy = new ZInst[end_pc];
 
-	for ( auto i = 0U; i < ninst; ++i )
+	for ( auto i = 0U; i < end_pc; ++i )
 		{
 		auto& iI = *instsI[i];
 		insts_copy[i] = iI;
@@ -228,7 +228,7 @@ void ZBody::InitProfile()
 		{
 		inst_count = new vector<int>;
 		inst_CPU = new vector<double>;
-		for ( auto i = 0U; i < ninst; ++i )
+		for ( auto i = 0U; i < end_pc; ++i )
 			{
 			inst_count->push_back(0);
 			inst_CPU->push_back(0.0);
@@ -245,7 +245,7 @@ ValPtr ZBody::Exec(Frame* f, StmtFlowType& flow)
 	double t = analysis_options.profile_ZAM ? util::curr_CPU_time() : 0.0;
 #endif
 
-	auto val = DoExec(f, 0, flow);
+	auto val = DoExec(f, flow);
 
 #ifdef DEBUG
 	if ( analysis_options.profile_ZAM )
@@ -255,10 +255,9 @@ ValPtr ZBody::Exec(Frame* f, StmtFlowType& flow)
 	return val;
 	}
 
-ValPtr ZBody::DoExec(Frame* f, int start_pc, StmtFlowType& flow)
+ValPtr ZBody::DoExec(Frame* f, StmtFlowType& flow)
 	{
-	int pc = start_pc;
+	int pc = 0;
-	const int end_pc = ninst;
 
 	// Return value, or nil if none.
 	const ZVal* ret_u = nullptr;
@@ -293,6 +292,9 @@ ValPtr ZBody::DoExec(Frame* f, int start_pc, StmtFlowType& flow)
 
 	flow = FLOW_RETURN; // can be over-written by a Hook-Break
 
+	// Clear any leftover error state.
+	ZAM_error = false;
+
 	while ( pc < end_pc && ! ZAM_error )
 		{
 		auto& z = insts[pc];
@@ -369,9 +371,6 @@ ValPtr ZBody::DoExec(Frame* f, int start_pc, StmtFlowType& flow)
 		delete[] frame;
 		}
 
-	// Clear any error state.
-	ZAM_error = false;
-
 	return result;
 	}
 
@@ -449,7 +448,7 @@ void ZBody::Dump() const
 
 	printf("Final code:\n");
 
-	for ( unsigned i = 0; i < ninst; ++i )
+	for ( unsigned i = 0; i < end_pc; ++i )
 		{
 		auto& inst = insts[i];
 		printf("%d: ", i);
@@ -472,25 +471,6 @@ TraversalCode ZBody::Traverse(TraversalCallback* cb) const
 	HANDLE_TC_STMT_POST(tc);
 	}
 
-ValPtr ZAMResumption::Exec(Frame* f, StmtFlowType& flow)
-	{
-	return am->DoExec(f, xfer_pc, flow);
-	}
-
-void ZAMResumption::StmtDescribe(ODesc* d) const
-	{
-	d->Add("<resumption of compiled code>");
-	}
-
-TraversalCode ZAMResumption::Traverse(TraversalCallback* cb) const
-	{
-	TraversalCode tc = cb->PreStmt(this);
-	HANDLE_TC_STMT_PRE(tc);
-
-	tc = cb->PostStmt(this);
-	HANDLE_TC_STMT_POST(tc);
-	}
-
 // Unary vector operation of v1 <vec-op> v2.
 static void vec_exec(ZOp op, TypePtr t, VectorVal*& v1, const VectorVal* v2, const ZInst& z)
 	{

src/script_opt/ZAM/ZBody.h

@@ -52,12 +52,10 @@ public:
 	void ProfileExecution() const;
 
 protected:
-	friend class ZAMResumption;
-
 	// Initializes profiling information, if needed.
 	void InitProfile();
 
-	ValPtr DoExec(Frame* f, int start_pc, StmtFlowType& flow);
+	ValPtr DoExec(Frame* f, StmtFlowType& flow);
 
 	// Run-time checking for "any" type being consistent with
 	// expected typed.  Returns true if the type match is okay.
@@ -73,7 +71,7 @@ private:
 	const char* func_name = nullptr;
 
 	const ZInst* insts = nullptr;
-	unsigned int ninst = 0;
+	unsigned int end_pc = 0;
 
 	FrameReMap frame_denizens;
 	int frame_size;
@@ -117,29 +115,6 @@ private:
 	CaseMaps<std::string> str_cases;
 	};
 
-// This is a statement that resumes execution into a code block in a
-// ZBody.  Used for deferred execution for "when" statements.
-
-class ZAMResumption : public Stmt
-	{
-public:
-	ZAMResumption(ZBody* _am, int _xfer_pc) : Stmt(STMT_ZAM_RESUMPTION), am(_am), xfer_pc(_xfer_pc)
-		{
-		}
-
-	ValPtr Exec(Frame* f, StmtFlowType& flow) override;
-
-	StmtPtr Duplicate() override { return {NewRef{}, this}; }
-
-	void StmtDescribe(ODesc* d) const override;
-
-protected:
-	TraversalCode Traverse(TraversalCallback* cb) const override;
-
-	ZBody* am;
-	int xfer_pc = 0;
-	};
-
 // Prints the execution profile.
 extern void report_ZOP_profile();