be-codegen-6800.c gen_shortcut() long value assignment.

[zu2]

I tried assigning a long value using gen_shortcut().It seems to work in a simple test.

--- ../Fuzix-Compiler-Kit/be-codegen-6800.c	2024-11-02 08:28:02
+++ be-codegen-6800.c	2024-11-02 14:42:14
@@ -1152,7 +1152,7 @@
 	struct node *r = n->right;
 	unsigned s = get_size(n->type);
 	unsigned nr = n->flags & NORETURN;
-	unsigned v;
+	unsigned v,vl,vr;
 
 	/* Don't generate unreachable code */
 	if (unreachable)
@@ -1283,7 +1283,25 @@
 					load_d_const(r->value);
 					op16d_on_ptr("st", "st", v + 2);
 					load_d_const(r->value >> 16);
+					op16d_on_ptr("st", "st", v);
+					invalidate_work();
+					return 1;
+				}
+			}
+			if (n->op == T_EQ && nr && s == 4 &&  l->op == T_LOCAL
+			&&  r->op == T_DEREF && r->right->op == T_LOCAL) {
+				vl = l->value;
+				vr = r->right->value;
+				printf("; T_EQ && T_LOCAL v=%d, vl=%d, vr=%d\n",v,vl,vr);
+				if(vl<252 && vr<252){
+					v  += load_x_with(l, 0);
+					vr = load_x_with(r->right, 0);
+					printf("; T_EQ make direct load/store v=%d, vr=%d\n",v,vr);
+					op16d_on_ptr("ld", "ld", vr + 2);
+					op16d_on_ptr("st", "st", v + 2);
+					op16d_on_ptr("ld", "ld", vr);
 					op16d_on_ptr("st", "st", v);
+					invalidate_work();
 					return 1;
 				}
 			}
@@ -1330,10 +1348,29 @@
 		}
 		return 0;
 	case T_PLUSEQ:
 		if (s == 1 && memop_const(n, "inc", nr, 2))
 			return 1;
 		if (s == 2 && add_to_node(n, 1, 1))
 			return 1;
+		if (s == 4 && nr && l->op == T_LOCAL && r->op == T_DEREF && r->right->op == T_LOCAL) {
+			v = n->value;
+			vl = l->value;
+			vr = r->right->value;
+			printf("; T_PLUSEQ && T_LOCAL v=%d, vl=%d, vr=%d\n",v,vl,vr);
+			if(vl<254 && vr<254){	// both offset < 254
+				vl = v + load_x_with(l, 0);
+				vr = load_x_with(r->right, 0);
+				printf("; T_PLUSEQ make direct load/add/store v=%d, vl=%d, vr=%d\n",v,vl,vr);
+				op16d_on_ptr("ld", "ld", vl + 2);
+				op16d_on_ptr("add", "adc", vr + 2);
+				op16d_on_ptr("st", "st", vl + 2);
+				op16d_on_ptr("ld", "ld", vl);
+				op16d_on_ptr("adc", "adc", vr);
+				op16d_on_ptr("st", "st", vl);
+				invalidate_work();
+				return 1;
+			}
+		}
 		return do_xeqop(n, "xpluseq");
 	case T_MINUSEQ:
 		if (s == 1 && memop_const(n, "dec", nr, 2))

sample program:

int
main(int argc, char **argv)
{
	long a = 1;
	unsigned long b = 100;
	long c;

	c = a;
	c += b;

	return !(c==a+b);
}

It compiles like this.

; T_EQ/EQPLUS v=0
; T_EQ && T_LOCAL v=0, vl=8, vr=0
;make local ptr off 8, rlim 252 noff 8
;make local ptr off 0, rlim 252 noff 0
; T_EQ make direct load/store v=8, vr=0
        ldb 3,x
        lda 2,x
        stb 11,x
        sta 10,x
        ldb 1,x
        lda 0,x
        stb 9,x
        sta 8,x
;
; T_PLUSEQ && T_LOCAL v=0, vl=8, vr=4
;make local ptr off 8, rlim 252 noff 8
;make local ptr off 4, rlim 252 noff 4
; T_PLUSEQ make direct load/add/store v=0, vl=8, vr=4
        ldb 11,x
        lda 10,x
        addb 7,x
        adca 6,x
        stb 11,x
        sta 10,x
        ldb 9,x
        lda 8,x
        adcb 5,x
        adca 4,x
        stb 9,x
        sta 8,x

I think there is an error in the code because I don't fully understand how to use load_x_with and make_local_ptr.

It seems possible to compile global variables and other calculations this way, but simply adding them would make the program size enormous. I'm thinking of a way to do this.