ZAM support for two-valued "for" loops over vectors

src/script_opt/ZAM/AM-Opt.cc

@@ -400,6 +400,16 @@ void ZAMCompiler::ComputeFrameLifetimes()
 				}
 				break;
 
+			case OP_NEXT_VECTOR_ITER_VAL_VAR_VVVV:
+				{
+				CheckSlotAssignment(inst->v2, inst);
+
+				auto depth = inst->loop_depth;
+				ExtendLifetime(inst->v1, EndOfLoop(inst, depth));
+				ExtendLifetime(inst->v2, EndOfLoop(inst, depth));
+				}
+				break;
+
 			case OP_NEXT_VECTOR_ITER_VVV:
 			case OP_NEXT_STRING_ITER_VVV:
 				// Sometimes loops are written that don't actually
@@ -916,6 +926,9 @@ bool ZAMCompiler::VarIsAssigned(int slot, const ZInstI* i) const
 		// *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

src/script_opt/ZAM/Branches.cc

@@ -171,8 +171,8 @@ void ZAMCompiler::SetV4(ZAMStmt s, const InstLabel l)
 
 	auto ot = inst->op_type;
 
-	ASSERT(ot == OP_VVVV || ot == OP_VVVV_I4);
+	ASSERT(ot == OP_VVVV || ot == OP_VVVV_I4 || ot == OP_VVVV_I3_I4);
-	if ( ot != OP_VVVV_I4 )
+	if ( ot == OP_VVVV )
 		inst->op_type = OP_VVVV_I4;
 	}
 

src/script_opt/ZAM/Ops.in

@@ -1761,6 +1761,30 @@ eval	auto& si = step_iters[z.v2];
 	frame[z.v1].uint_val = si.iter;
 	si.IterFinished();
 
+internal-op Next-Vector-Iter-Val-Var
+# v1 = iteration variable
+# v2 = value variable
+# v3 = iteration info
+# v4 = branch target if loop done
+op1-read-write
+type VVVV
+eval	auto& si = step_iters[z.v3];
+	if ( si.IsDoneIterating() )
+		BRANCH(v4)
+	const auto& vv = *si.vv;
+	if ( ! vv[si.iter] )
+		{ // Account for vector hole.  Re-execute for next position.
+		si.IterFinished();
+		--pc;	// so we then increment to here again
+		break;
+		}
+	frame[z.v1].uint_val = si.iter;
+	if ( z.is_managed )
+		frame[z.v2] = BuildVal(vv[si.iter]->ToVal(z.t), z.t);
+	else
+		frame[z.v2] = *vv[si.iter];
+	si.IterFinished();
+
 
 internal-op Init-String-Loop
 type VV

src/script_opt/ZAM/Stmt.cc

@@ -864,6 +864,7 @@ const ZAMStmt ZAMCompiler::LoopOverVector(const ForStmt* f, const NameExpr* val)
 	{
 	auto loop_vars = f->LoopVars();
 	auto loop_var = (*loop_vars)[0];
+	auto value_var = f->ValueVar();
 
 	int iter_slot = num_step_iters++;
 
@@ -873,8 +874,20 @@ const ZAMStmt ZAMCompiler::LoopOverVector(const ForStmt* f, const NameExpr* val)
 	auto init_end = AddInst(z);
 	auto iter_head = StartingBlock();
 
+	if ( value_var )
+		{
+		z = ZInstI(OP_NEXT_VECTOR_ITER_VAL_VAR_VVVV, FrameSlot(loop_var), FrameSlot(value_var),
+		           iter_slot, 0);
+		z.t = value_var->GetType();
+		z.is_managed = ZVal::IsManagedType(z.t);
+		z.op_type = OP_VVVV_I3_I4;
+		}
+
+	else
+		{
 		z = ZInstI(OP_NEXT_VECTOR_ITER_VVV, FrameSlot(loop_var), iter_slot, 0);
 		z.op_type = OP_VVV_I2_I3;
+		}
 
 	return FinishLoop(iter_head, z, f->LoopBody(), iter_slot, false);
 	}
@@ -944,7 +957,9 @@ const ZAMStmt ZAMCompiler::FinishLoop(const ZAMStmt iter_head, ZInstI& iter_stmt
 	auto final_stmt = AddInst(z);
 
 	auto ot = iter_stmt.op_type;
-	if ( ot == OP_VVV_I3 || ot == OP_VVV_I2_I3 )
+	if ( ot == OP_VVVV_I3_I4 )
+		SetV4(loop_iter, GoToTarget(final_stmt));
+	else if ( ot == OP_VVV_I3 || ot == OP_VVV_I2_I3 )
 		SetV3(loop_iter, GoToTarget(final_stmt));
 	else
 		SetV2(loop_iter, GoToTarget(final_stmt));

src/script_opt/ZAM/ZInst.cc

@@ -331,9 +331,16 @@ string ZInstI::VName(int n, const FrameMap* frame_ids, const FrameReMap* remappi
 		auto inst_num_u = static_cast<zeek_uint_t>(inst_num);
 		for ( i = 0; i < map.id_start.size(); ++i )
 			{
-			// See discussion for ZInst::VName.
+			// See discussion for ZInst::VName, though this is
-			if ( (n == 1 && map.id_start[i] > inst_num_u) ||
+			// a tad different since we have the general notion
-			     (n > 1 && map.id_start[i] >= inst_num_u) )
+			// of AssignsToSlot().
+			if ( AssignsToSlot(n) )
+				{
+				if ( map.id_start[i] > inst_num_u )
+					break;
+				}
+
+			else if ( map.id_start[i] >= inst_num_u )
 				// Went too far.
 				break;
 			}
@@ -441,6 +448,18 @@ bool ZInstI::AssignsToSlot1() const
 	return false;
 	}
 
+bool ZInstI::AssignsToSlot(int slot) const
+	{
+	switch ( op )
+		{
+		case OP_NEXT_VECTOR_ITER_VAL_VAR_VVVV:
+			return slot == 1 || slot == 2;
+
+		default:
+			return slot == 1 && AssignsToSlot1();
+		}
+	}
+
 bool ZInstI::UsesSlot(int slot) const
 	{
 	auto fl = op1_flavor[op];

src/script_opt/ZAM/ZInst.h

@@ -222,6 +222,10 @@ public:
 	// given by slot 1 (v1).
 	bool AssignsToSlot1() const;
 
+	// True if the given instruction assigns to the frame location
+	// corresponding to the given slot.
+	bool AssignsToSlot(int slot) const;
+
 	// True if the given instruction uses the value in the given frame
 	// slot. (Assigning to the slot does not constitute using the value.)
 	bool UsesSlot(int slot) const;