From 8e2eed0130bb158dcf5674ce34448822dd0d6408 Mon Sep 17 00:00:00 2001
From: "(Tim) Efthimis Kritikos" <efkf@firemail.cc>
Date: Sat, 4 May 2024 07:31:09 +0100
Subject: [PATCH] CPU: Added another runtime sanity check and made them
 optional in config.h

---
 config.h |  2 +-
 cpu.c    | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/config.h b/config.h
index 1b3a427..a16f069 100644
--- a/config.h
+++ b/config.h
@@ -1 +1 @@
-//#define USE_AALIB
+#define RUNTIME_CHECKS // uncomment to trade runtime checks for negligible performance improvements
diff --git a/cpu.c b/cpu.c
index aea391b..08fbdee 100644
--- a/cpu.c
+++ b/cpu.c
@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <math.h>
 #include <string.h>
+#include "config.h"
 
 /* Known errors:
  * 1) Exec does the calculations on the first clock cycle, there is a bug where in some cases exec isn't run on the last cycle and because of this the CPU still works.
@@ -336,8 +337,18 @@ int delay_values[]={
 };
 
 
+/*
+ * RETURN CODES:
+ * 0 : success
+ * 1 : Normal execute error
+ * 2 : Internal error
+ */
 int exec(struct simdata_t *simdata){
 	free_instr_list(&simdata->cpu_gui_hints->executing_list);
+#ifdef RUNTIME_CHECKS
+	if(simdata->registers->SP&0xFF000000)
+		return 2;
+#endif
 	if(simdata->exec_data->valid==1){
 		simdata->fetch_data->exec_done=0;
 		simdata->decode_data->exec_done=0;
@@ -346,7 +357,11 @@ int exec(struct simdata_t *simdata){
 		if(simdata->exec_data->valid==0)
 			return 0;
 		int condition=0;
+#ifdef RUNTIME_CHECKS
 #define		SANITY_CHECK(x) { if(x>0x0F){return 1;} }
+#else
+#define		SANITY_CHECK(x) {}
+#endif
 		switch(simdata->exec_data->EXEC_ACTION){
 			case CALL:
 			case JUMP: