Change function call information to be variable length.

Before this change FunctionCallInfoData, the struct arguments etc for
V1 function calls are stored in, always had space for
FUNC_MAX_ARGS/100 arguments, storing datums and their nullness in two
arrays.  For nearly every function call 100 arguments is far more than
needed, therefore wasting memory. Arg and argnull being two separate
arrays also guarantees that to access a single argument, two
cachelines have to be touched.

Change the layout so there's a single variable-length array with pairs
of value / isnull. That drastically reduces memory consumption for
most function calls (on x86-64 a two argument function now uses
64bytes, previously 936 bytes), and makes it very likely that argument
value and its nullness are on the same cacheline.

Arguments are stored in a new NullableDatum struct, which, due to
padding, needs more memory per argument than before. But as usually
far fewer arguments are stored, and individual arguments are cheaper
to access, that's still a clear win.  It's likely that there's other
places where conversion to NullableDatum arrays would make sense,
e.g. TupleTableSlots, but that's for another commit.

Because the function call information is now variable-length
allocations have to take the number of arguments into account. For
heap allocations that can be done with SizeForFunctionCallInfoData(),
for on-stack allocations there's a new LOCAL_FCINFO(name, nargs) macro
that helps to allocate an appropriately sized and aligned variable.

Some places with stack allocation function call information don't know
the number of arguments at compile time, and currently variably sized
stack allocations aren't allowed in postgres. Therefore allow for
FUNC_MAX_ARGS space in these cases. They're not that common, so for
now that seems acceptable.

Because of the need to allocate FunctionCallInfo of the appropriate
size, older extensions may need to update their code. To avoid subtle
breakages, the FunctionCallInfoData struct has been renamed to
FunctionCallInfoBaseData. Most code only references FunctionCallInfo,
so that shouldn't cause much collateral damage.

This change is also a prerequisite for more efficient expression JIT
compilation (by allocating the function call information on the stack,
allowing LLVM to optimize it away); previously the size of the call
information caused problems inside LLVM's optimizer.

Author: Andres Freund
Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/20180605172952.x34m5uz6ju6enaem@alap3.anarazel.de

7 files changed, 230 insertions, 194 deletions

diff --git a/src/backend/executor/README b/src/backend/executor/README
index ddbd62b4dba..05f197bc75b 100644
--- a/src/backend/executor/README
+++ b/src/backend/executor/README
@@ -124,7 +124,7 @@ For example, "a + b" (one OpExpr, with two Var expressions) would be
 represented as two steps to fetch the Var values, and one step for the
 evaluation of the function underlying the + operator.  The steps for the
 Vars would have their resvalue/resnull pointing directly to the appropriate
-arg[] and argnull[] array elements in the FunctionCallInfoData struct that
+args[].value .isnull elements in the FunctionCallInfoBaseData struct that
 is used by the function evaluation step, thus avoiding extra work to copy
 the result values around.
 
@@ -145,7 +145,7 @@ sub-expressions.
 Each ExecInitExprRec() call has to specify where that subexpression's
 results are to be stored (via the resv/resnull parameters).  This allows
 the above scenario of evaluating a (sub-)expression directly into
-fcinfo->arg/argnull, but also requires some care: target Datum/isnull
+fcinfo->args[].value/isnull, but also requires some care: target Datum/isnull
 variables may not be shared with another ExecInitExprRec() unless the
 results are only needed by steps executing before further usages of those
 target Datum/isnull variables.  Due to the non-recursiveness of the
@@ -158,7 +158,7 @@ not enough space.  Because of that it is *not* allowed to point directly
 into any of the steps during expression initialization.  Therefore, the
 resv/resnull for a subexpression usually point to some storage that is
 palloc'd separately from the steps array.  For instance, the
-FunctionCallInfoData for a function call step is separately allocated
+FunctionCallInfoBaseData for a function call step is separately allocated
 rather than being part of the ExprEvalStep array.  The overall result
 of a complete expression is typically returned into the resvalue/resnull
 fields of the ExprState node itself.
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 4047d24b03e..2e061a5ee36 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -966,7 +966,7 @@ ExecInitExprRec(Expr *node, ExprState *state,
 
 				/* Set up the primary fmgr lookup information */
 				finfo = palloc0(sizeof(FmgrInfo));
-				fcinfo = palloc0(sizeof(FunctionCallInfoData));
+				fcinfo = palloc0(SizeForFunctionCallInfo(2));
 				fmgr_info(opexpr->opfuncid, finfo);
 				fmgr_info_set_expr((Node *) node, finfo);
 				InitFunctionCallInfoData(*fcinfo, finfo, 2,
@@ -974,7 +974,7 @@ ExecInitExprRec(Expr *node, ExprState *state,
 
 				/* Evaluate scalar directly into left function argument */
 				ExecInitExprRec(scalararg, state,
-								&fcinfo->arg[0], &fcinfo->argnull[0]);
+								&fcinfo->args[0].value, &fcinfo->args[0].isnull);
 
 				/*
 				 * Evaluate array argument into our return value.  There's no
@@ -1263,7 +1263,7 @@ ExecInitExprRec(Expr *node, ExprState *state,
 
 				/* lookup the source type's output function */
 				scratch.d.iocoerce.finfo_out = palloc0(sizeof(FmgrInfo));
-				scratch.d.iocoerce.fcinfo_data_out = palloc0(sizeof(FunctionCallInfoData));
+				scratch.d.iocoerce.fcinfo_data_out = palloc0(SizeForFunctionCallInfo(1));
 
 				getTypeOutputInfo(exprType((Node *) iocoerce->arg),
 								  &iofunc, &typisvarlena);
@@ -1275,7 +1275,7 @@ ExecInitExprRec(Expr *node, ExprState *state,
 
 				/* lookup the result type's input function */
 				scratch.d.iocoerce.finfo_in = palloc0(sizeof(FmgrInfo));
-				scratch.d.iocoerce.fcinfo_data_in = palloc0(sizeof(FunctionCallInfoData));
+				scratch.d.iocoerce.fcinfo_data_in = palloc0(SizeForFunctionCallInfo(3));
 
 				getTypeInputInfo(iocoerce->resulttype,
 								 &iofunc, &typioparam);
@@ -1290,10 +1290,10 @@ ExecInitExprRec(Expr *node, ExprState *state,
 				 * function, since they're constants.
 				 */
 				fcinfo_in = scratch.d.iocoerce.fcinfo_data_in;
-				fcinfo_in->arg[1] = ObjectIdGetDatum(typioparam);
-				fcinfo_in->argnull[1] = false;
-				fcinfo_in->arg[2] = Int32GetDatum(-1);
-				fcinfo_in->argnull[2] = false;
+				fcinfo_in->args[1].value = ObjectIdGetDatum(typioparam);
+				fcinfo_in->args[1].isnull = false;
+				fcinfo_in->args[2].value = Int32GetDatum(-1);
+				fcinfo_in->args[2].isnull = false;
 
 				ExprEvalPushStep(state, &scratch);
 				break;
@@ -1735,7 +1735,7 @@ ExecInitExprRec(Expr *node, ExprState *state,
 
 					/* Set up the primary fmgr lookup information */
 					finfo = palloc0(sizeof(FmgrInfo));
-					fcinfo = palloc0(sizeof(FunctionCallInfoData));
+					fcinfo = palloc0(SizeForFunctionCallInfo(2));
 					fmgr_info(proc, finfo);
 					fmgr_info_set_expr((Node *) node, finfo);
 					InitFunctionCallInfoData(*fcinfo, finfo, 2,
@@ -1750,9 +1750,9 @@ ExecInitExprRec(Expr *node, ExprState *state,
 
 					/* evaluate left and right args directly into fcinfo */
 					ExecInitExprRec(left_expr, state,
-									&fcinfo->arg[0], &fcinfo->argnull[0]);
+									&fcinfo->args[0].value, &fcinfo->args[0].isnull);
 					ExecInitExprRec(right_expr, state,
-									&fcinfo->arg[1], &fcinfo->argnull[1]);
+									&fcinfo->args[1].value, &fcinfo->args[1].isnull);
 
 					scratch.opcode = EEOP_ROWCOMPARE_STEP;
 					scratch.d.rowcompare_step.finfo = finfo;
@@ -1878,7 +1878,7 @@ ExecInitExprRec(Expr *node, ExprState *state,
 
 				/* Perform function lookup */
 				finfo = palloc0(sizeof(FmgrInfo));
-				fcinfo = palloc0(sizeof(FunctionCallInfoData));
+				fcinfo = palloc0(SizeForFunctionCallInfo(2));
 				fmgr_info(typentry->cmp_proc, finfo);
 				fmgr_info_set_expr((Node *) node, finfo);
 				InitFunctionCallInfoData(*fcinfo, finfo, 2,
@@ -2187,7 +2187,7 @@ ExecInitFunc(ExprEvalStep *scratch, Expr *node, List *args, Oid funcid,
 
 	/* Allocate function lookup data and parameter workspace for this call */
 	scratch->d.func.finfo = palloc0(sizeof(FmgrInfo));
-	scratch->d.func.fcinfo_data = palloc0(sizeof(FunctionCallInfoData));
+	scratch->d.func.fcinfo_data = palloc0(SizeForFunctionCallInfo(nargs));
 	flinfo = scratch->d.func.finfo;
 	fcinfo = scratch->d.func.fcinfo_data;
 
@@ -2226,13 +2226,14 @@ ExecInitFunc(ExprEvalStep *scratch, Expr *node, List *args, Oid funcid,
 			 */
 			Const	   *con = (Const *) arg;
 
-			fcinfo->arg[argno] = con->constvalue;
-			fcinfo->argnull[argno] = con->constisnull;
+			fcinfo->args[argno].value = con->constvalue;
+			fcinfo->args[argno].isnull = con->constisnull;
 		}
 		else
 		{
 			ExecInitExprRec(arg, state,
-							&fcinfo->arg[argno], &fcinfo->argnull[argno]);
+							&fcinfo->args[argno].value,
+							&fcinfo->args[argno].isnull);
 		}
 		argno++;
 	}
@@ -2961,10 +2962,11 @@ ExecBuildAggTrans(AggState *aggstate, AggStatePerPhase phase,
 		AggStatePerTrans pertrans = &aggstate->pertrans[transno];
 		int			argno;
 		int			setno;
-		FunctionCallInfo trans_fcinfo = &pertrans->transfn_fcinfo;
+		FunctionCallInfo trans_fcinfo = pertrans->transfn_fcinfo;
 		ListCell   *arg;
 		ListCell   *bail;
 		List	   *adjust_bailout = NIL;
+		NullableDatum *strictargs = NULL;
 		bool	   *strictnulls = NULL;
 
 		/*
@@ -3002,7 +3004,7 @@ ExecBuildAggTrans(AggState *aggstate, AggStatePerPhase phase,
 			Assert(pertrans->numSortCols == 0);
 			Assert(list_length(pertrans->aggref->args) == 1);
 
-			strictnulls = trans_fcinfo->argnull + 1;
+			strictargs = trans_fcinfo->args + 1;
 			source_tle = (TargetEntry *) linitial(pertrans->aggref->args);
 
 			/*
@@ -3016,21 +3018,21 @@ ExecBuildAggTrans(AggState *aggstate, AggStatePerPhase phase,
 				 * value
 				 */
 				ExecInitExprRec(source_tle->expr, state,
-								&trans_fcinfo->arg[argno + 1],
-								&trans_fcinfo->argnull[argno + 1]);
+								&trans_fcinfo->args[argno + 1].value,
+								&trans_fcinfo->args[argno + 1].isnull);
 			}
 			else
 			{
-				FunctionCallInfo ds_fcinfo = &pertrans->deserialfn_fcinfo;
+				FunctionCallInfo ds_fcinfo = pertrans->deserialfn_fcinfo;
 
 				/* evaluate argument */
 				ExecInitExprRec(source_tle->expr, state,
-								&ds_fcinfo->arg[0],
-								&ds_fcinfo->argnull[0]);
+								&ds_fcinfo->args[0].value,
+								&ds_fcinfo->args[0].isnull);
 
 				/* Dummy second argument for type-safety reasons */
-				ds_fcinfo->arg[1] = PointerGetDatum(NULL);
-				ds_fcinfo->argnull[1] = false;
+				ds_fcinfo->args[1].value = PointerGetDatum(NULL);
+				ds_fcinfo->args[1].isnull = false;
 
 				/*
 				 * Don't call a strict deserialization function with NULL
@@ -3044,8 +3046,8 @@ ExecBuildAggTrans(AggState *aggstate, AggStatePerPhase phase,
 				scratch.d.agg_deserialize.aggstate = aggstate;
 				scratch.d.agg_deserialize.fcinfo_data = ds_fcinfo;
 				scratch.d.agg_deserialize.jumpnull = -1;	/* adjust later */
-				scratch.resvalue = &trans_fcinfo->arg[argno + 1];
-				scratch.resnull = &trans_fcinfo->argnull[argno + 1];
+				scratch.resvalue = &trans_fcinfo->args[argno + 1].value;
+				scratch.resnull = &trans_fcinfo->args[argno + 1].isnull;
 
 				ExprEvalPushStep(state, &scratch);
 				adjust_bailout = lappend_int(adjust_bailout,
@@ -3062,7 +3064,7 @@ ExecBuildAggTrans(AggState *aggstate, AggStatePerPhase phase,
 			/*
 			 * Normal transition function without ORDER BY / DISTINCT.
 			 */
-			strictnulls = trans_fcinfo->argnull + 1;
+			strictargs = trans_fcinfo->args + 1;
 
 			foreach(arg, pertrans->aggref->args)
 			{
@@ -3073,8 +3075,8 @@ ExecBuildAggTrans(AggState *aggstate, AggStatePerPhase phase,
 				 * value
 				 */
 				ExecInitExprRec(source_tle->expr, state,
-								&trans_fcinfo->arg[argno + 1],
-								&trans_fcinfo->argnull[argno + 1]);
+								&trans_fcinfo->args[argno + 1].value,
+								&trans_fcinfo->args[argno + 1].isnull);
 				argno++;
 			}
 		}
@@ -3122,8 +3124,12 @@ ExecBuildAggTrans(AggState *aggstate, AggStatePerPhase phase,
 		 */
 		if (trans_fcinfo->flinfo->fn_strict && pertrans->numTransInputs > 0)
 		{
-			scratch.opcode = EEOP_AGG_STRICT_INPUT_CHECK;
+			if (strictnulls)
+				scratch.opcode = EEOP_AGG_STRICT_INPUT_CHECK_NULLS;
+			else
+				scratch.opcode = EEOP_AGG_STRICT_INPUT_CHECK_ARGS;
 			scratch.d.agg_strict_input_check.nulls = strictnulls;
+			scratch.d.agg_strict_input_check.args = strictargs;
 			scratch.d.agg_strict_input_check.jumpnull = -1; /* adjust later */
 			scratch.d.agg_strict_input_check.nargs = pertrans->numTransInputs;
 			ExprEvalPushStep(state, &scratch);
@@ -3177,7 +3183,8 @@ ExecBuildAggTrans(AggState *aggstate, AggStatePerPhase phase,
 				Assert(as->d.jump.jumpdone == -1);
 				as->d.jump.jumpdone = state->steps_len;
 			}
-			else if (as->opcode == EEOP_AGG_STRICT_INPUT_CHECK)
+			else if (as->opcode == EEOP_AGG_STRICT_INPUT_CHECK_ARGS ||
+					 as->opcode == EEOP_AGG_STRICT_INPUT_CHECK_NULLS)
 			{
 				Assert(as->d.agg_strict_input_check.jumpnull == -1);
 				as->d.agg_strict_input_check.jumpnull = state->steps_len;
@@ -3312,7 +3319,7 @@ ExecBuildAggTransCall(ExprState *state, AggState *aggstate,
  */
 ExprState *
 ExecBuildGroupingEqual(TupleDesc ldesc, TupleDesc rdesc,
-					   const TupleTableSlotOps *lops, const TupleTableSlotOps *rops,
+					   const TupleTableSlotOps * lops, const TupleTableSlotOps * rops,
 					   int numCols,
 					   const AttrNumber *keyColIdx,
 					   const Oid *eqfunctions,
@@ -3389,7 +3396,7 @@ ExecBuildGroupingEqual(TupleDesc ldesc, TupleDesc rdesc,
 
 		/* Set up the primary fmgr lookup information */
 		finfo = palloc0(sizeof(FmgrInfo));
-		fcinfo = palloc0(sizeof(FunctionCallInfoData));
+		fcinfo = palloc0(SizeForFunctionCallInfo(2));
 		fmgr_info(foid, finfo);
 		fmgr_info_set_expr(NULL, finfo);
 		InitFunctionCallInfoData(*fcinfo, finfo, 2,
@@ -3399,16 +3406,16 @@ ExecBuildGroupingEqual(TupleDesc ldesc, TupleDesc rdesc,
 		scratch.opcode = EEOP_INNER_VAR;
 		scratch.d.var.attnum = attno - 1;
 		scratch.d.var.vartype = latt->atttypid;
-		scratch.resvalue = &fcinfo->arg[0];
-		scratch.resnull = &fcinfo->argnull[0];
+		scratch.resvalue = &fcinfo->args[0].value;
+		scratch.resnull = &fcinfo->args[0].isnull;
 		ExprEvalPushStep(state, &scratch);
 
 		/* right arg */
 		scratch.opcode = EEOP_OUTER_VAR;
 		scratch.d.var.attnum = attno - 1;
 		scratch.d.var.vartype = ratt->atttypid;
-		scratch.resvalue = &fcinfo->arg[1];
-		scratch.resnull = &fcinfo->argnull[1];
+		scratch.resvalue = &fcinfo->args[1].value;
+		scratch.resnull = &fcinfo->args[1].isnull;
 		ExprEvalPushStep(state, &scratch);
 
 		/* evaluate distinctness */
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 5a7206f5882..5c5f655645d 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -387,7 +387,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		&&CASE_EEOP_ALTERNATIVE_SUBPLAN,
 		&&CASE_EEOP_AGG_STRICT_DESERIALIZE,
 		&&CASE_EEOP_AGG_DESERIALIZE,
-		&&CASE_EEOP_AGG_STRICT_INPUT_CHECK,
+		&&CASE_EEOP_AGG_STRICT_INPUT_CHECK_ARGS,
+		&&CASE_EEOP_AGG_STRICT_INPUT_CHECK_NULLS,
 		&&CASE_EEOP_AGG_INIT_TRANS,
 		&&CASE_EEOP_AGG_STRICT_TRANS_CHECK,
 		&&CASE_EEOP_AGG_PLAIN_TRANS_BYVAL,
@@ -631,14 +632,14 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		EEO_CASE(EEOP_FUNCEXPR_STRICT)
 		{
 			FunctionCallInfo fcinfo = op->d.func.fcinfo_data;
-			bool	   *argnull = fcinfo->argnull;
+			NullableDatum *args = fcinfo->args;
 			int			argno;
 			Datum		d;
 
 			/* strict function, so check for NULL args */
 			for (argno = 0; argno < op->d.func.nargs; argno++)
 			{
-				if (argnull[argno])
+				if (args[argno].isnull)
 				{
 					*op->resnull = true;
 					goto strictfail;
@@ -1054,8 +1055,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 				FunctionCallInfo fcinfo_out;
 
 				fcinfo_out = op->d.iocoerce.fcinfo_data_out;
-				fcinfo_out->arg[0] = *op->resvalue;
-				fcinfo_out->argnull[0] = false;
+				fcinfo_out->args[0].value = *op->resvalue;
+				fcinfo_out->args[0].isnull = false;
 
 				fcinfo_out->isnull = false;
 				str = DatumGetCString(FunctionCallInvoke(fcinfo_out));
@@ -1071,8 +1072,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 				Datum		d;
 
 				fcinfo_in = op->d.iocoerce.fcinfo_data_in;
-				fcinfo_in->arg[0] = PointerGetDatum(str);
-				fcinfo_in->argnull[0] = *op->resnull;
+				fcinfo_in->args[0].value = PointerGetDatum(str);
+				fcinfo_in->args[0].isnull = *op->resnull;
 				/* second and third arguments are already set up */
 
 				fcinfo_in->isnull = false;
@@ -1099,23 +1100,23 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		{
 			/*
 			 * IS DISTINCT FROM must evaluate arguments (already done into
-			 * fcinfo->arg/argnull) to determine whether they are NULL; if
-			 * either is NULL then the result is determined.  If neither is
-			 * NULL, then proceed to evaluate the comparison function, which
-			 * is just the type's standard equality operator.  We need not
-			 * care whether that function is strict.  Because the handling of
-			 * nulls is different, we can't just reuse EEOP_FUNCEXPR.
+			 * fcinfo->args) to determine whether they are NULL; if either is
+			 * NULL then the result is determined.  If neither is NULL, then
+			 * proceed to evaluate the comparison function, which is just the
+			 * type's standard equality operator.  We need not care whether
+			 * that function is strict.  Because the handling of nulls is
+			 * different, we can't just reuse EEOP_FUNCEXPR.
 			 */
 			FunctionCallInfo fcinfo = op->d.func.fcinfo_data;
 
 			/* check function arguments for NULLness */
-			if (fcinfo->argnull[0] && fcinfo->argnull[1])
+			if (fcinfo->args[0].isnull && fcinfo->args[1].isnull)
 			{
 				/* Both NULL? Then is not distinct... */
 				*op->resvalue = BoolGetDatum(false);
 				*op->resnull = false;
 			}
-			else if (fcinfo->argnull[0] || fcinfo->argnull[1])
+			else if (fcinfo->args[0].isnull || fcinfo->args[1].isnull)
 			{
 				/* Only one is NULL? Then is distinct... */
 				*op->resvalue = BoolGetDatum(true);
@@ -1141,12 +1142,12 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		{
 			FunctionCallInfo fcinfo = op->d.func.fcinfo_data;
 
-			if (fcinfo->argnull[0] && fcinfo->argnull[1])
+			if (fcinfo->args[0].isnull && fcinfo->args[1].isnull)
 			{
 				*op->resvalue = BoolGetDatum(true);
 				*op->resnull = false;
 			}
-			else if (fcinfo->argnull[0] || fcinfo->argnull[1])
+			else if (fcinfo->args[0].isnull || fcinfo->args[1].isnull)
 			{
 				*op->resvalue = BoolGetDatum(false);
 				*op->resnull = false;
@@ -1167,12 +1168,12 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		EEO_CASE(EEOP_NULLIF)
 		{
 			/*
-			 * The arguments are already evaluated into fcinfo->arg/argnull.
+			 * The arguments are already evaluated into fcinfo->args.
 			 */
 			FunctionCallInfo fcinfo = op->d.func.fcinfo_data;
 
 			/* if either argument is NULL they can't be equal */
-			if (!fcinfo->argnull[0] && !fcinfo->argnull[1])
+			if (!fcinfo->args[0].isnull && !fcinfo->args[1].isnull)
 			{
 				Datum		result;
 
@@ -1190,8 +1191,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 			}
 
 			/* Arguments aren't equal, so return the first one */
-			*op->resvalue = fcinfo->arg[0];
-			*op->resnull = fcinfo->argnull[0];
+			*op->resvalue = fcinfo->args[0].value;
+			*op->resnull = fcinfo->args[0].isnull;
 
 			EEO_NEXT();
 		}
@@ -1257,7 +1258,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 
 			/* force NULL result if strict fn and NULL input */
 			if (op->d.rowcompare_step.finfo->fn_strict &&
-				(fcinfo->argnull[0] || fcinfo->argnull[1]))
+				(fcinfo->args[0].isnull || fcinfo->args[1].isnull))
 			{
 				*op->resnull = true;
 				EEO_JUMP(op->d.rowcompare_step.jumpnull);
@@ -1496,10 +1497,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		/* evaluate a strict aggregate deserialization function */
 		EEO_CASE(EEOP_AGG_STRICT_DESERIALIZE)
 		{
-			bool	   *argnull = op->d.agg_deserialize.fcinfo_data->argnull;
-
 			/* Don't call a strict deserialization function with NULL input */
-			if (argnull[0])
+			if (op->d.agg_deserialize.fcinfo_data->args[0].isnull)
 				EEO_JUMP(op->d.agg_deserialize.jumpnull);
 
 			/* fallthrough */
@@ -1529,7 +1528,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 		 * Check that a strict aggregate transition / combination function's
 		 * input is not NULL.
 		 */
-		EEO_CASE(EEOP_AGG_STRICT_INPUT_CHECK)
+		EEO_CASE(EEOP_AGG_STRICT_INPUT_CHECK_NULLS)
 		{
 			int			argno;
 			bool	   *nulls = op->d.agg_strict_input_check.nulls;
@@ -1543,6 +1542,20 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 			EEO_NEXT();
 		}
 
+		EEO_CASE(EEOP_AGG_STRICT_INPUT_CHECK_ARGS)
+		{
+			int			argno;
+			NullableDatum *args = op->d.agg_strict_input_check.args;
+			int			nargs = op->d.agg_strict_input_check.nargs;
+
+			for (argno = 0; argno < nargs; argno++)
+			{
+				if (args[argno].isnull)
+					EEO_JUMP(op->d.agg_strict_input_check.jumpnull);
+			}
+			EEO_NEXT();
+		}
+
 		/*
 		 * Initialize an aggregate's first value if necessary.
 		 */
@@ -1613,7 +1626,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 
 			Assert(pertrans->transtypeByVal);
 
-			fcinfo = &pertrans->transfn_fcinfo;
+			fcinfo = pertrans->transfn_fcinfo;
 
 			/* cf. select_current_set() */
 			aggstate->curaggcontext = op->d.agg_trans.aggcontext;
@@ -1625,8 +1638,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 			/* invoke transition function in per-tuple context */
 			oldContext = MemoryContextSwitchTo(aggstate->tmpcontext->ecxt_per_tuple_memory);
 
-			fcinfo->arg[0] = pergroup->transValue;
-			fcinfo->argnull[0] = pergroup->transValueIsNull;
+			fcinfo->args[0].value = pergroup->transValue;
+			fcinfo->args[0].isnull = pergroup->transValueIsNull;
 			fcinfo->isnull = false; /* just in case transfn doesn't set it */
 
 			newVal = FunctionCallInvoke(fcinfo);
@@ -1664,7 +1677,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 
 			Assert(!pertrans->transtypeByVal);
 
-			fcinfo = &pertrans->transfn_fcinfo;
+			fcinfo = pertrans->transfn_fcinfo;
 
 			/* cf. select_current_set() */
 			aggstate->curaggcontext = op->d.agg_trans.aggcontext;
@@ -1676,8 +1689,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
 			/* invoke transition function in per-tuple context */
 			oldContext = MemoryContextSwitchTo(aggstate->tmpcontext->ecxt_per_tuple_memory);
 
-			fcinfo->arg[0] = pergroup->transValue;
-			fcinfo->argnull[0] = pergroup->transValueIsNull;
+			fcinfo->args[0].value = pergroup->transValue;
+			fcinfo->args[0].isnull = pergroup->transValueIsNull;
 			fcinfo->isnull = false; /* just in case transfn doesn't set it */
 
 			newVal = FunctionCallInvoke(fcinfo);
@@ -2075,7 +2088,7 @@ ExecJustApplyFuncToCase(ExprState *state, ExprContext *econtext, bool *isnull)
 {
 	ExprEvalStep *op = &state->steps[0];
 	FunctionCallInfo fcinfo;
-	bool	   *argnull;
+	NullableDatum *args;
 	int			argno;
 	Datum		d;
 
@@ -2089,12 +2102,12 @@ ExecJustApplyFuncToCase(ExprState *state, ExprContext *econtext, bool *isnull)
 	op++;
 
 	fcinfo = op->d.func.fcinfo_data;
-	argnull = fcinfo->argnull;
+	args = fcinfo->args;
 
 	/* strict function, so check for NULL args */
 	for (argno = 0; argno < op->d.func.nargs; argno++)
 	{
-		if (argnull[argno])
+		if (args[argno].isnull)
 		{
 			*isnull = true;
 			return (Datum) 0;
@@ -2220,14 +2233,14 @@ ExecEvalFuncExprStrictFusage(ExprState *state, ExprEvalStep *op,
 
 	FunctionCallInfo fcinfo = op->d.func.fcinfo_data;
 	PgStat_FunctionCallUsage fcusage;
-	bool	   *argnull = fcinfo->argnull;
+	NullableDatum *args = fcinfo->args;
 	int			argno;
 	Datum		d;
 
 	/* strict function, so check for NULL args */
 	for (argno = 0; argno < op->d.func.nargs; argno++)
 	{
-		if (argnull[argno])
+		if (args[argno].isnull)
 		{
 			*op->resnull = true;
 			return;
@@ -2317,8 +2330,8 @@ ExecEvalParamExtern(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
 void
 ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op)
 {
+	LOCAL_FCINFO(fcinfo, 0);
 	SQLValueFunction *svf = op->d.sqlvaluefunction.svf;
-	FunctionCallInfoData fcinfo;
 
 	*op->resnull = false;
 
@@ -2350,24 +2363,24 @@ ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op)
 		case SVFOP_CURRENT_ROLE:
 		case SVFOP_CURRENT_USER:
 		case SVFOP_USER:
-			InitFunctionCallInfoData(fcinfo, NULL, 0, InvalidOid, NULL, NULL);
-			*op->resvalue = current_user(&fcinfo);
-			*op->resnull = fcinfo.isnull;
+			InitFunctionCallInfoData(*fcinfo, NULL, 0, InvalidOid, NULL, NULL);
+			*op->resvalue = current_user(fcinfo);
+			*op->resnull = fcinfo->isnull;
 			break;
 		case SVFOP_SESSION_USER:
-			InitFunctionCallInfoData(fcinfo, NULL, 0, InvalidOid, NULL, NULL);
-			*op->resvalue = session_user(&fcinfo);
-			*op->resnull = fcinfo.isnull;
+			InitFunctionCallInfoData(*fcinfo, NULL, 0, InvalidOid, NULL, NULL);
+			*op->resvalue = session_user(fcinfo);
+			*op->resnull = fcinfo->isnull;
 			break;
 		case SVFOP_CURRENT_CATALOG:
-			InitFunctionCallInfoData(fcinfo, NULL, 0, InvalidOid, NULL, NULL);
-			*op->resvalue = current_database(&fcinfo);
-			*op->resnull = fcinfo.isnull;
+			InitFunctionCallInfoData(*fcinfo, NULL, 0, InvalidOid, NULL, NULL);
+			*op->resvalue = current_database(fcinfo);
+			*op->resnull = fcinfo->isnull;
 			break;
 		case SVFOP_CURRENT_SCHEMA:
-			InitFunctionCallInfoData(fcinfo, NULL, 0, InvalidOid, NULL, NULL);
-			*op->resvalue = current_schema(&fcinfo);
-			*op->resnull = fcinfo.isnull;
+			InitFunctionCallInfoData(*fcinfo, NULL, 0, InvalidOid, NULL, NULL);
+			*op->resvalue = current_schema(fcinfo);
+			*op->resnull = fcinfo->isnull;
 			break;
 	}
 }
@@ -2800,8 +2813,8 @@ ExecEvalMinMax(ExprState *state, ExprEvalStep *op)
 	int			off;
 
 	/* set at initialization */
-	Assert(fcinfo->argnull[0] == false);
-	Assert(fcinfo->argnull[1] == false);
+	Assert(fcinfo->args[0].isnull == false);
+	Assert(fcinfo->args[1].isnull == false);
 
 	/* default to null result */
 	*op->resnull = true;
@@ -2823,8 +2836,8 @@ ExecEvalMinMax(ExprState *state, ExprEvalStep *op)
 			int			cmpresult;
 
 			/* apply comparison function */
-			fcinfo->arg[0] = *op->resvalue;
-			fcinfo->arg[1] = values[off];
+			fcinfo->args[0].value = *op->resvalue;
+			fcinfo->args[1].value = values[off];
 
 			fcinfo->isnull = false;
 			cmpresult = DatumGetInt32(FunctionCallInvoke(fcinfo));
@@ -3324,7 +3337,7 @@ ExecEvalConvertRowtype(ExprState *state, ExprEvalStep *op, ExprContext *econtext
  * Evaluate "scalar op ANY/ALL (array)".
  *
  * Source array is in our result area, scalar arg is already evaluated into
- * fcinfo->arg[0]/argnull[0].
+ * fcinfo->args[0].
  *
  * The operator always yields boolean, and we combine the results across all
  * array elements using OR and AND (for ANY and ALL respectively).  Of course
@@ -3376,7 +3389,7 @@ ExecEvalScalarArrayOp(ExprState *state, ExprEvalStep *op)
 	 * If the scalar is NULL, and the function is strict, return NULL; no
 	 * point in iterating the loop.
 	 */
-	if (fcinfo->argnull[0] && strictfunc)
+	if (fcinfo->args[0].isnull && strictfunc)
 	{
 		*op->resnull = true;
 		return;
@@ -3416,20 +3429,20 @@ ExecEvalScalarArrayOp(ExprState *state, ExprEvalStep *op)
 		/* Get array element, checking for NULL */
 		if (bitmap && (*bitmap & bitmask) == 0)
 		{
-			fcinfo->arg[1] = (Datum) 0;
-			fcinfo->argnull[1] = true;
+			fcinfo->args[1].value = (Datum) 0;
+			fcinfo->args[1].isnull = true;
 		}
 		else
 		{
 			elt = fetch_att(s, typbyval, typlen);
 			s = att_addlength_pointer(s, typlen, s);
 			s = (char *) att_align_nominal(s, typalign);
-			fcinfo->arg[1] = elt;
-			fcinfo->argnull[1] = false;
+			fcinfo->args[1].value = elt;
+			fcinfo->args[1].isnull = false;
 		}
 
 		/* Call comparison function */
-		if (fcinfo->argnull[1] && strictfunc)
+		if (fcinfo->args[1].isnull && strictfunc)
 		{
 			fcinfo->isnull = true;
 			thisresult = (Datum) 0;
@@ -4044,7 +4057,7 @@ ExecEvalSysVar(ExprState *state, ExprEvalStep *op, ExprContext *econtext,
 void
 ExecAggInitGroup(AggState *aggstate, AggStatePerTrans pertrans, AggStatePerGroup pergroup)
 {
-	FunctionCallInfo fcinfo = &pertrans->transfn_fcinfo;
+	FunctionCallInfo fcinfo = pertrans->transfn_fcinfo;
 	MemoryContext oldContext;
 
 	/*
@@ -4055,7 +4068,7 @@ ExecAggInitGroup(AggState *aggstate, AggStatePerTrans pertrans, AggStatePerGroup
 	 */
 	oldContext = MemoryContextSwitchTo(
 									   aggstate->curaggcontext->ecxt_per_tuple_memory);
-	pergroup->transValue = datumCopy(fcinfo->arg[1],
+	pergroup->transValue = datumCopy(fcinfo->args[1].value,
 									 pertrans->transtypeByVal,
 									 pertrans->transtypeLen);
 	pergroup->transValueIsNull = false;
diff --git a/src/backend/executor/execSRF.c b/src/backend/executor/execSRF.c
index 0c086c52904..265250186a1 100644
--- a/src/backend/executor/execSRF.c
+++ b/src/backend/executor/execSRF.c
@@ -109,7 +109,7 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 	Oid			funcrettype;
 	bool		returnsTuple;
 	bool		returnsSet = false;
-	FunctionCallInfoData fcinfo;
+	FunctionCallInfo fcinfo;
 	PgStat_FunctionCallUsage fcusage;
 	ReturnSetInfo rsinfo;
 	HeapTupleData tmptup;
@@ -141,6 +141,8 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 	rsinfo.setResult = NULL;
 	rsinfo.setDesc = NULL;
 
+	fcinfo = palloc(SizeForFunctionCallInfo(list_length(setexpr->args)));
+
 	/*
 	 * Normally the passed expression tree will be a SetExprState, since the
 	 * grammar only allows a function call at the top level of a table
@@ -157,9 +159,9 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 		 * This path is similar to ExecMakeFunctionResultSet.
 		 */
 		returnsSet = setexpr->funcReturnsSet;
-		InitFunctionCallInfoData(fcinfo, &(setexpr->func),
+		InitFunctionCallInfoData(*fcinfo, &(setexpr->func),
 								 list_length(setexpr->args),
-								 setexpr->fcinfo_data.fncollation,
+								 setexpr->fcinfo->fncollation,
 								 NULL, (Node *) &rsinfo);
 
 		/*
@@ -174,7 +176,7 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 		 */
 		MemoryContextReset(argContext);
 		oldcontext = MemoryContextSwitchTo(argContext);
-		ExecEvalFuncArgs(&fcinfo, setexpr->args, econtext);
+		ExecEvalFuncArgs(fcinfo, setexpr->args, econtext);
 		MemoryContextSwitchTo(oldcontext);
 
 		/*
@@ -186,9 +188,9 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 		{
 			int			i;
 
-			for (i = 0; i < fcinfo.nargs; i++)
+			for (i = 0; i < fcinfo->nargs; i++)
 			{
-				if (fcinfo.argnull[i])
+				if (fcinfo->args[i].isnull)
 					goto no_function_result;
 			}
 		}
@@ -196,7 +198,7 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 	else
 	{
 		/* Treat setexpr as a generic expression */
-		InitFunctionCallInfoData(fcinfo, NULL, 0, InvalidOid, NULL, NULL);
+		InitFunctionCallInfoData(*fcinfo, NULL, 0, InvalidOid, NULL, NULL);
 	}
 
 	/*
@@ -224,11 +226,11 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 		/* Call the function or expression one time */
 		if (!setexpr->elidedFuncState)
 		{
-			pgstat_init_function_usage(&fcinfo, &fcusage);
+			pgstat_init_function_usage(fcinfo, &fcusage);
 
-			fcinfo.isnull = false;
+			fcinfo->isnull = false;
 			rsinfo.isDone = ExprSingleResult;
-			result = FunctionCallInvoke(&fcinfo);
+			result = FunctionCallInvoke(fcinfo);
 
 			pgstat_end_function_usage(&fcusage,
 									  rsinfo.isDone != ExprMultipleResult);
@@ -236,7 +238,7 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 		else
 		{
 			result =
-				ExecEvalExpr(setexpr->elidedFuncState, econtext, &fcinfo.isnull);
+				ExecEvalExpr(setexpr->elidedFuncState, econtext, &fcinfo->isnull);
 			rsinfo.isDone = ExprSingleResult;
 		}
 
@@ -277,7 +279,7 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 			 */
 			if (returnsTuple)
 			{
-				if (!fcinfo.isnull)
+				if (!fcinfo->isnull)
 				{
 					HeapTupleHeader td = DatumGetHeapTupleHeader(result);
 
@@ -338,7 +340,7 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 			else
 			{
 				/* Scalar-type case: just store the function result */
-				tuplestore_putvalues(tupstore, tupdesc, &result, &fcinfo.isnull);
+				tuplestore_putvalues(tupstore, tupdesc, &result, &fcinfo->isnull);
 			}
 
 			/*
@@ -547,7 +549,7 @@ restart:
 	 * rows from this SRF have been returned, otherwise ValuePerCall SRFs
 	 * would reference freed memory after the first returned row.
 	 */
-	fcinfo = &fcache->fcinfo_data;
+	fcinfo = fcache->fcinfo;
 	arguments = fcache->args;
 	if (!fcache->setArgsValid)
 	{
@@ -587,7 +589,7 @@ restart:
 	{
 		for (i = 0; i < fcinfo->nargs; i++)
 		{
-			if (fcinfo->argnull[i])
+			if (fcinfo->args[i].isnull)
 			{
 				callit = false;
 				break;
@@ -678,6 +680,7 @@ init_sexpr(Oid foid, Oid input_collation, Expr *node,
 		   MemoryContext sexprCxt, bool allowSRF, bool needDescForSRF)
 {
 	AclResult	aclresult;
+	size_t		numargs = list_length(sexpr->args);
 
 	/* Check permission to call function */
 	aclresult = pg_proc_aclcheck(foid, GetUserId(), ACL_EXECUTE);
@@ -704,8 +707,10 @@ init_sexpr(Oid foid, Oid input_collation, Expr *node,
 	fmgr_info_set_expr((Node *) sexpr->expr, &(sexpr->func));
 
 	/* Initialize the function call parameter struct as well */
-	InitFunctionCallInfoData(sexpr->fcinfo_data, &(sexpr->func),
-							 list_length(sexpr->args),
+	sexpr->fcinfo =
+		(FunctionCallInfo) palloc(SizeForFunctionCallInfo(numargs));
+	InitFunctionCallInfoData(*sexpr->fcinfo, &(sexpr->func),
+							 numargs,
 							 input_collation, NULL, NULL);
 
 	/* If function returns set, check if that's allowed by caller */
@@ -820,9 +825,9 @@ ExecEvalFuncArgs(FunctionCallInfo fcinfo,
 	{
 		ExprState  *argstate = (ExprState *) lfirst(arg);
 
-		fcinfo->arg[i] = ExecEvalExpr(argstate,
-									  econtext,
-									  &fcinfo->argnull[i]);
+		fcinfo->args[i].value = ExecEvalExpr(argstate,
+											 econtext,
+											 &fcinfo->args[i].isnull);
 		i++;
 	}
 
diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index de41588105e..c6b7203f813 100644
--- a/src/backend/executor/functions.c
+++ b/src/backend/executor/functions.c
@@ -933,8 +933,8 @@ postquel_sub_params(SQLFunctionCachePtr fcache,
 		{
 			ParamExternData *prm = &paramLI->params[i];
 
-			prm->value = fcinfo->arg[i];
-			prm->isnull = fcinfo->argnull[i];
+			prm->value = fcinfo->args[i].value;
+			prm->isnull = fcinfo->args[i].isnull;
 			prm->pflags = 0;
 			prm->ptype = fcache->pinfo->argtypes[i];
 		}
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index 508c9195743..2a260a71f24 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -553,7 +553,7 @@ advance_transition_function(AggState *aggstate,
 							AggStatePerTrans pertrans,
 							AggStatePerGroup pergroupstate)
 {
-	FunctionCallInfo fcinfo = &pertrans->transfn_fcinfo;
+	FunctionCallInfo fcinfo = pertrans->transfn_fcinfo;
 	MemoryContext oldContext;
 	Datum		newVal;
 
@@ -568,7 +568,7 @@ advance_transition_function(AggState *aggstate,
 
 		for (i = 1; i <= numTransInputs; i++)
 		{
-			if (fcinfo->argnull[i])
+			if (fcinfo->args[i].isnull)
 				return;
 		}
 		if (pergroupstate->noTransValue)
@@ -584,7 +584,7 @@ advance_transition_function(AggState *aggstate,
 			 */
 			oldContext = MemoryContextSwitchTo(
 											   aggstate->curaggcontext->ecxt_per_tuple_memory);
-			pergroupstate->transValue = datumCopy(fcinfo->arg[1],
+			pergroupstate->transValue = datumCopy(fcinfo->args[1].value,
 												  pertrans->transtypeByVal,
 												  pertrans->transtypeLen);
 			pergroupstate->transValueIsNull = false;
@@ -613,8 +613,8 @@ advance_transition_function(AggState *aggstate,
 	/*
 	 * OK to call the transition function
 	 */
-	fcinfo->arg[0] = pergroupstate->transValue;
-	fcinfo->argnull[0] = pergroupstate->transValueIsNull;
+	fcinfo->args[0].value = pergroupstate->transValue;
+	fcinfo->args[0].isnull = pergroupstate->transValueIsNull;
 	fcinfo->isnull = false;		/* just in case transfn doesn't set it */
 
 	newVal = FunctionCallInvoke(fcinfo);
@@ -717,7 +717,7 @@ process_ordered_aggregate_single(AggState *aggstate,
 	bool		isDistinct = (pertrans->numDistinctCols > 0);
 	Datum		newAbbrevVal = (Datum) 0;
 	Datum		oldAbbrevVal = (Datum) 0;
-	FunctionCallInfo fcinfo = &pertrans->transfn_fcinfo;
+	FunctionCallInfo fcinfo = pertrans->transfn_fcinfo;
 	Datum	   *newVal;
 	bool	   *isNull;
 
@@ -726,8 +726,8 @@ process_ordered_aggregate_single(AggState *aggstate,
 	tuplesort_performsort(pertrans->sortstates[aggstate->current_set]);
 
 	/* Load the column into argument 1 (arg 0 will be transition value) */
-	newVal = fcinfo->arg + 1;
-	isNull = fcinfo->argnull + 1;
+	newVal = &fcinfo->args[1].value;
+	isNull = &fcinfo->args[1].isnull;
 
 	/*
 	 * Note: if input type is pass-by-ref, the datums returned by the sort are
@@ -803,7 +803,7 @@ process_ordered_aggregate_multi(AggState *aggstate,
 								AggStatePerGroup pergroupstate)
 {
 	ExprContext *tmpcontext = aggstate->tmpcontext;
-	FunctionCallInfo fcinfo = &pertrans->transfn_fcinfo;
+	FunctionCallInfo fcinfo = pertrans->transfn_fcinfo;
 	TupleTableSlot *slot1 = pertrans->sortslot;
 	TupleTableSlot *slot2 = pertrans->uniqslot;
 	int			numTransInputs = pertrans->numTransInputs;
@@ -843,8 +843,8 @@ process_ordered_aggregate_multi(AggState *aggstate,
 			/* Start from 1, since the 0th arg will be the transition value */
 			for (i = 0; i < numTransInputs; i++)
 			{
-				fcinfo->arg[i + 1] = slot1->tts_values[i];
-				fcinfo->argnull[i + 1] = slot1->tts_isnull[i];
+				fcinfo->args[i + 1].value = slot1->tts_values[i];
+				fcinfo->args[i + 1].isnull = slot1->tts_isnull[i];
 			}
 
 			advance_transition_function(aggstate, pertrans, pergroupstate);
@@ -897,7 +897,7 @@ finalize_aggregate(AggState *aggstate,
 				   AggStatePerGroup pergroupstate,
 				   Datum *resultVal, bool *resultIsNull)
 {
-	FunctionCallInfoData fcinfo;
+	LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
 	bool		anynull = false;
 	MemoryContext oldContext;
 	int			i;
@@ -917,10 +917,10 @@ finalize_aggregate(AggState *aggstate,
 	{
 		ExprState  *expr = (ExprState *) lfirst(lc);
 
-		fcinfo.arg[i] = ExecEvalExpr(expr,
-									 aggstate->ss.ps.ps_ExprContext,
-									 &fcinfo.argnull[i]);
-		anynull |= fcinfo.argnull[i];
+		fcinfo->args[i].value = ExecEvalExpr(expr,
+											 aggstate->ss.ps.ps_ExprContext,
+											 &fcinfo->args[i].isnull);
+		anynull |= fcinfo->args[i].isnull;
 		i++;
 	}
 
@@ -934,27 +934,28 @@ finalize_aggregate(AggState *aggstate,
 		/* set up aggstate->curperagg for AggGetAggref() */
 		aggstate->curperagg = peragg;
 
-		InitFunctionCallInfoData(fcinfo, &peragg->finalfn,
+		InitFunctionCallInfoData(*fcinfo, &peragg->finalfn,
 								 numFinalArgs,
 								 pertrans->aggCollation,
 								 (void *) aggstate, NULL);
 
 		/* Fill in the transition state value */
-		fcinfo.arg[0] = MakeExpandedObjectReadOnly(pergroupstate->transValue,
-												   pergroupstate->transValueIsNull,
-												   pertrans->transtypeLen);
-		fcinfo.argnull[0] = pergroupstate->transValueIsNull;
+		fcinfo->args[0].value =
+			MakeExpandedObjectReadOnly(pergroupstate->transValue,
+									   pergroupstate->transValueIsNull,
+									   pertrans->transtypeLen);
+		fcinfo->args[0].isnull = pergroupstate->transValueIsNull;
 		anynull |= pergroupstate->transValueIsNull;
 
 		/* Fill any remaining argument positions with nulls */
 		for (; i < numFinalArgs; i++)
 		{
-			fcinfo.arg[i] = (Datum) 0;
-			fcinfo.argnull[i] = true;
+			fcinfo->args[i].value = (Datum) 0;
+			fcinfo->args[i].isnull = true;
 			anynull = true;
 		}
 
-		if (fcinfo.flinfo->fn_strict && anynull)
+		if (fcinfo->flinfo->fn_strict && anynull)
 		{
 			/* don't call a strict function with NULL inputs */
 			*resultVal = (Datum) 0;
@@ -962,8 +963,8 @@ finalize_aggregate(AggState *aggstate,
 		}
 		else
 		{
-			*resultVal = FunctionCallInvoke(&fcinfo);
-			*resultIsNull = fcinfo.isnull;
+			*resultVal = FunctionCallInvoke(fcinfo);
+			*resultIsNull = fcinfo->isnull;
 		}
 		aggstate->curperagg = NULL;
 	}
@@ -1018,12 +1019,13 @@ finalize_partialaggregate(AggState *aggstate,
 		}
 		else
 		{
-			FunctionCallInfo fcinfo = &pertrans->serialfn_fcinfo;
+			FunctionCallInfo fcinfo = pertrans->serialfn_fcinfo;
 
-			fcinfo->arg[0] = MakeExpandedObjectReadOnly(pergroupstate->transValue,
-														pergroupstate->transValueIsNull,
-														pertrans->transtypeLen);
-			fcinfo->argnull[0] = pergroupstate->transValueIsNull;
+			fcinfo->args[0].value =
+				MakeExpandedObjectReadOnly(pergroupstate->transValue,
+										   pergroupstate->transValueIsNull,
+										   pertrans->transtypeLen);
+			fcinfo->args[0].isnull = pergroupstate->transValueIsNull;
 
 			*resultVal = FunctionCallInvoke(fcinfo);
 			*resultIsNull = fcinfo->isnull;
@@ -2927,7 +2929,9 @@ build_pertrans_for_aggref(AggStatePerTrans pertrans,
 		fmgr_info(aggtransfn, &pertrans->transfn);
 		fmgr_info_set_expr((Node *) combinefnexpr, &pertrans->transfn);
 
-		InitFunctionCallInfoData(pertrans->transfn_fcinfo,
+		pertrans->transfn_fcinfo =
+			(FunctionCallInfo) palloc(SizeForFunctionCallInfo(2));
+		InitFunctionCallInfoData(*pertrans->transfn_fcinfo,
 								 &pertrans->transfn,
 								 2,
 								 pertrans->aggCollation,
@@ -2947,6 +2951,7 @@ build_pertrans_for_aggref(AggStatePerTrans pertrans,
 	else
 	{
 		Expr	   *transfnexpr;
+		size_t		numInputs = pertrans->numTransInputs + 1;
 
 		/*
 		 * Set up infrastructure for calling the transfn.  Note that invtrans
@@ -2965,9 +2970,11 @@ build_pertrans_for_aggref(AggStatePerTrans pertrans,
 		fmgr_info(aggtransfn, &pertrans->transfn);
 		fmgr_info_set_expr((Node *) transfnexpr, &pertrans->transfn);
 
-		InitFunctionCallInfoData(pertrans->transfn_fcinfo,
+		pertrans->transfn_fcinfo =
+			(FunctionCallInfo) palloc(SizeForFunctionCallInfo(numInputs));
+		InitFunctionCallInfoData(*pertrans->transfn_fcinfo,
 								 &pertrans->transfn,
-								 pertrans->numTransInputs + 1,
+								 numInputs,
 								 pertrans->aggCollation,
 								 (void *) aggstate, NULL);
 
@@ -3003,7 +3010,9 @@ build_pertrans_for_aggref(AggStatePerTrans pertrans,
 		fmgr_info(aggserialfn, &pertrans->serialfn);
 		fmgr_info_set_expr((Node *) serialfnexpr, &pertrans->serialfn);
 
-		InitFunctionCallInfoData(pertrans->serialfn_fcinfo,
+		pertrans->serialfn_fcinfo =
+			(FunctionCallInfo) palloc(SizeForFunctionCallInfo(1));
+		InitFunctionCallInfoData(*pertrans->serialfn_fcinfo,
 								 &pertrans->serialfn,
 								 1,
 								 InvalidOid,
@@ -3017,7 +3026,9 @@ build_pertrans_for_aggref(AggStatePerTrans pertrans,
 		fmgr_info(aggdeserialfn, &pertrans->deserialfn);
 		fmgr_info_set_expr((Node *) deserialfnexpr, &pertrans->deserialfn);
 
-		InitFunctionCallInfoData(pertrans->deserialfn_fcinfo,
+		pertrans->deserialfn_fcinfo =
+			(FunctionCallInfo) palloc(SizeForFunctionCallInfo(2));
+		InitFunctionCallInfoData(*pertrans->deserialfn_fcinfo,
 								 &pertrans->deserialfn,
 								 2,
 								 InvalidOid,
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index 7ae56074ca8..731391f1907 100644
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -241,10 +241,9 @@ advance_windowaggregate(WindowAggState *winstate,
 						WindowStatePerFunc perfuncstate,
 						WindowStatePerAgg peraggstate)
 {
+	LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
 	WindowFuncExprState *wfuncstate = perfuncstate->wfuncstate;
 	int			numArguments = perfuncstate->numArguments;
-	FunctionCallInfoData fcinfodata;
-	FunctionCallInfo fcinfo = &fcinfodata;
 	Datum		newVal;
 	ListCell   *arg;
 	int			i;
@@ -273,8 +272,8 @@ advance_windowaggregate(WindowAggState *winstate,
 	{
 		ExprState  *argstate = (ExprState *) lfirst(arg);
 
-		fcinfo->arg[i] = ExecEvalExpr(argstate, econtext,
-									  &fcinfo->argnull[i]);
+		fcinfo->args[i].value = ExecEvalExpr(argstate, econtext,
+											 &fcinfo->args[i].isnull);
 		i++;
 	}
 
@@ -287,7 +286,7 @@ advance_windowaggregate(WindowAggState *winstate,
 		 */
 		for (i = 1; i <= numArguments; i++)
 		{
-			if (fcinfo->argnull[i])
+			if (fcinfo->args[i].isnull)
 			{
 				MemoryContextSwitchTo(oldContext);
 				return;
@@ -306,7 +305,7 @@ advance_windowaggregate(WindowAggState *winstate,
 		if (peraggstate->transValueCount == 0 && peraggstate->transValueIsNull)
 		{
 			MemoryContextSwitchTo(peraggstate->aggcontext);
-			peraggstate->transValue = datumCopy(fcinfo->arg[1],
+			peraggstate->transValue = datumCopy(fcinfo->args[1].value,
 												peraggstate->transtypeByVal,
 												peraggstate->transtypeLen);
 			peraggstate->transValueIsNull = false;
@@ -339,8 +338,8 @@ advance_windowaggregate(WindowAggState *winstate,
 							 numArguments + 1,
 							 perfuncstate->winCollation,
 							 (void *) winstate, NULL);
-	fcinfo->arg[0] = peraggstate->transValue;
-	fcinfo->argnull[0] = peraggstate->transValueIsNull;
+	fcinfo->args[0].value = peraggstate->transValue;
+	fcinfo->args[0].isnull = peraggstate->transValueIsNull;
 	winstate->curaggcontext = peraggstate->aggcontext;
 	newVal = FunctionCallInvoke(fcinfo);
 	winstate->curaggcontext = NULL;
@@ -418,10 +417,9 @@ advance_windowaggregate_base(WindowAggState *winstate,
 							 WindowStatePerFunc perfuncstate,
 							 WindowStatePerAgg peraggstate)
 {
+	LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
 	WindowFuncExprState *wfuncstate = perfuncstate->wfuncstate;
 	int			numArguments = perfuncstate->numArguments;
-	FunctionCallInfoData fcinfodata;
-	FunctionCallInfo fcinfo = &fcinfodata;
 	Datum		newVal;
 	ListCell   *arg;
 	int			i;
@@ -450,8 +448,8 @@ advance_windowaggregate_base(WindowAggState *winstate,
 	{
 		ExprState  *argstate = (ExprState *) lfirst(arg);
 
-		fcinfo->arg[i] = ExecEvalExpr(argstate, econtext,
-									  &fcinfo->argnull[i]);
+		fcinfo->args[i].value = ExecEvalExpr(argstate, econtext,
+											 &fcinfo->args[i].isnull);
 		i++;
 	}
 
@@ -464,7 +462,7 @@ advance_windowaggregate_base(WindowAggState *winstate,
 		 */
 		for (i = 1; i <= numArguments; i++)
 		{
-			if (fcinfo->argnull[i])
+			if (fcinfo->args[i].isnull)
 			{
 				MemoryContextSwitchTo(oldContext);
 				return true;
@@ -510,8 +508,8 @@ advance_windowaggregate_base(WindowAggState *winstate,
 							 numArguments + 1,
 							 perfuncstate->winCollation,
 							 (void *) winstate, NULL);
-	fcinfo->arg[0] = peraggstate->transValue;
-	fcinfo->argnull[0] = peraggstate->transValueIsNull;
+	fcinfo->args[0].value = peraggstate->transValue;
+	fcinfo->args[0].isnull = peraggstate->transValueIsNull;
 	winstate->curaggcontext = peraggstate->aggcontext;
 	newVal = FunctionCallInvoke(fcinfo);
 	winstate->curaggcontext = NULL;
@@ -591,30 +589,31 @@ finalize_windowaggregate(WindowAggState *winstate,
 	 */
 	if (OidIsValid(peraggstate->finalfn_oid))
 	{
+		LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
 		int			numFinalArgs = peraggstate->numFinalArgs;
-		FunctionCallInfoData fcinfo;
 		bool		anynull;
 		int			i;
 
-		InitFunctionCallInfoData(fcinfo, &(peraggstate->finalfn),
+		InitFunctionCallInfoData(fcinfodata.fcinfo, &(peraggstate->finalfn),
 								 numFinalArgs,
 								 perfuncstate->winCollation,
 								 (void *) winstate, NULL);
-		fcinfo.arg[0] = MakeExpandedObjectReadOnly(peraggstate->transValue,
-												   peraggstate->transValueIsNull,
-												   peraggstate->transtypeLen);
-		fcinfo.argnull[0] = peraggstate->transValueIsNull;
+		fcinfo->args[0].value =
+			MakeExpandedObjectReadOnly(peraggstate->transValue,
+									   peraggstate->transValueIsNull,
+									   peraggstate->transtypeLen);
+		fcinfo->args[0].isnull = peraggstate->transValueIsNull;
 		anynull = peraggstate->transValueIsNull;
 
 		/* Fill any remaining argument positions with nulls */
 		for (i = 1; i < numFinalArgs; i++)
 		{
-			fcinfo.arg[i] = (Datum) 0;
-			fcinfo.argnull[i] = true;
+			fcinfo->args[i].value = (Datum) 0;
+			fcinfo->args[i].isnull = true;
 			anynull = true;
 		}
 
-		if (fcinfo.flinfo->fn_strict && anynull)
+		if (fcinfo->flinfo->fn_strict && anynull)
 		{
 			/* don't call a strict function with NULL inputs */
 			*result = (Datum) 0;
@@ -623,9 +622,9 @@ finalize_windowaggregate(WindowAggState *winstate,
 		else
 		{
 			winstate->curaggcontext = peraggstate->aggcontext;
-			*result = FunctionCallInvoke(&fcinfo);
+			*result = FunctionCallInvoke(fcinfo);
 			winstate->curaggcontext = NULL;
-			*isnull = fcinfo.isnull;
+			*isnull = fcinfo->isnull;
 		}
 	}
 	else
@@ -1032,7 +1031,7 @@ static void
 eval_windowfunction(WindowAggState *winstate, WindowStatePerFunc perfuncstate,
 					Datum *result, bool *isnull)
 {
-	FunctionCallInfoData fcinfo;
+	LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
 	MemoryContext oldContext;
 
 	oldContext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_tuple_memory);
@@ -1043,24 +1042,25 @@ eval_windowfunction(WindowAggState *winstate, WindowStatePerFunc perfuncstate,
 	 * implementations to support varying numbers of arguments.  The real info
 	 * goes through the WindowObject, which is passed via fcinfo->context.
 	 */
-	InitFunctionCallInfoData(fcinfo, &(perfuncstate->flinfo),
+	InitFunctionCallInfoData(*fcinfo, &(perfuncstate->flinfo),
 							 perfuncstate->numArguments,
 							 perfuncstate->winCollation,
 							 (void *) perfuncstate->winobj, NULL);
 	/* Just in case, make all the regular argument slots be null */
-	memset(fcinfo.argnull, true, perfuncstate->numArguments);
+	for (int argno = 0; argno < perfuncstate->numArguments; argno++)
+		fcinfo->args[argno].isnull = true;
 	/* Window functions don't have a current aggregate context, either */
 	winstate->curaggcontext = NULL;
 
-	*result = FunctionCallInvoke(&fcinfo);
-	*isnull = fcinfo.isnull;
+	*result = FunctionCallInvoke(fcinfo);
+	*isnull = fcinfo->isnull;
 
 	/*
 	 * Make sure pass-by-ref data is allocated in the appropriate context. (We
 	 * need this in case the function returns a pointer into some short-lived
 	 * tuple, as is entirely possible.)
 	 */
-	if (!perfuncstate->resulttypeByVal && !fcinfo.isnull &&
+	if (!perfuncstate->resulttypeByVal && !fcinfo->isnull &&
 		!MemoryContextContains(CurrentMemoryContext,
 							   DatumGetPointer(*result)))
 		*result = datumCopy(*result,