Change TupleTableSlot->tts_nvalid to type AttrNumber.

Previously it was an int / 4 bytes. The maximum number of attributes
in a tuple is restricted by the maximum value Var->varattno, which is
an AttrNumber/int16. Hence use the same data type for
TupleTableSlot->tts_nvalid.

Author: Ashutosh Bapat
Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de

src/backend/jit/llvm/llvmjit_deform.c

@@ -304,7 +304,7 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc, int natts)
 
 		for (attnum = 0; attnum < natts; attnum++)
 		{
-			LLVMValueRef v_attno = l_int32_const(attnum);
+			LLVMValueRef v_attno = l_int16_const(attnum);
 
 			LLVMAddCase(v_switch, v_attno, attcheckattnoblocks[attnum]);
 		}
@@ -691,7 +691,7 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc, int natts)
 	{
 		LLVMValueRef v_off = LLVMBuildLoad(b, v_offp, "");
 
-		LLVMBuildStore(b, l_int32_const(natts), v_nvalidp);
+		LLVMBuildStore(b, l_int16_const(natts), v_nvalidp);
 		v_off = LLVMBuildTrunc(b, v_off, LLVMInt32Type(), "");
 		LLVMBuildStore(b, v_off, v_slotoffp);
 		LLVMBuildStore(b, l_int8_const(1), v_slowp);

src/backend/jit/llvm/llvmjit_expr.c

@@ -324,7 +324,7 @@ llvm_compile_expr(ExprState *state)
 										  "");
 					LLVMBuildCondBr(b,
 									LLVMBuildICmp(b, LLVMIntUGE, v_nvalid,
-												  l_int32_const(op->d.fetch.last_var),
+												  l_int16_const(op->d.fetch.last_var),
 												  ""),
 									opblocks[i + 1], b_fetch);
 

src/include/executor/tuptable.h

@@ -125,7 +125,7 @@ typedef struct TupleTableSlot
 	MemoryContext tts_mcxt;		/* slot itself is in this context */
 	Buffer		tts_buffer;		/* tuple's buffer, or InvalidBuffer */
 #define FIELDNO_TUPLETABLESLOT_NVALID 9
-	int			tts_nvalid;		/* # of valid values in tts_values */
+	AttrNumber	tts_nvalid;		/* # of valid values in tts_values */
 #define FIELDNO_TUPLETABLESLOT_VALUES 10
 	Datum	   *tts_values;		/* current per-attribute values */
 #define FIELDNO_TUPLETABLESLOT_ISNULL 11