Fix cog label headache

Author: Wuerfel21

backends/asm/optimize_ir.c

@@ -965,6 +965,7 @@ AddSubVal(IR *ir)
 }
 
 extern Operand *mulfunc, *unsmulfunc, *divfunc, *unsdivfunc, *muldiva, *muldivb;
+extern Operand *putcogreg;
 
 static bool isMulDivFunc(Operand *func) {
     return !!func && (func == mulfunc || func == unsmulfunc || func == divfunc || func == unsdivfunc);
@@ -1226,6 +1227,8 @@ doIsDeadAfter(IR *instr, Operand *op, int level, IR **stack)
                     return true; // Value not actually used, goes dead.
                 } else if (isResult(op) && isMulDivFunc(ir->dst)) {
                     /* Result not affected by mul/div */
+                } else if (isResult(op) && putcogreg && ir->dst == putcogreg) {
+                    /* Result not (directly) affected by wrcog */
                 } else if (isResult(op)) {
                     if (ir->cond == COND_TRUE) return true; // Results get set by functions
                 } else {
@@ -2934,8 +2937,16 @@ int OptimizeReturnValues(IRList *irl) {
             }
             // All OK, do replace
             for (IR *ir=irl->head;ir;ir=ir->next) {
-                if (ir->src == local) ir->src = res;
-                if (ir->dst == local) ir->dst = res;
+                if (ir->src == local) {
+                    ir->src = res;
+                } else if (ir->src && ir->src->kind == IMM_COG_LABEL && !strcmp(ir->src->name,local->name)) {
+                    ir->src = NewOperand(IMM_COG_LABEL,res->name,ir->src->val);
+                } 
+                if (ir->dst == local) {
+                    ir->dst = res;
+                } else if (ir->dst && ir->dst->kind == IMM_COG_LABEL && !strcmp(ir->dst->name,local->name)) {
+                    ir->dst = NewOperand(IMM_COG_LABEL,res->name,ir->dst->val);
+                }
             }
             change++;
         }
@@ -4272,7 +4283,6 @@ FindNamedOperand(IRList *irl, const char *name, int val)
  * we can replace it with
  *   mov x, y
  */
-extern Operand *putcogreg;
 
 static int
 IsMovIndirect(IR *ir, IR *ir_prev, IR *ir_next)