Allow casts int to int

frontends/p4/typeChecking/typeChecker.cpp

@@ -729,7 +729,9 @@ bool TypeInference::canCastBetween(const IR::Type* dest, const IR::Type* src) co
             return b->size == 1 && !b->isSigned;
         }
     } else if (src->is<IR::Type_InfInt>()) {
-        return dest->is<IR::Type_Bits>() || dest->is<IR::Type_Boolean>();
+        return dest->is<IR::Type_Bits>() ||
+                dest->is<IR::Type_Boolean>() ||
+                dest->is<IR::Type_InfInt>();
     } else if (src->is<IR::Type_Newtype>()) {
         auto st = getTypeType(src->to<IR::Type_Newtype>()->type);
         return typeMap->equivalent(dest, st);

testdata/p4_16_samples/issue3219.p4

@@ -0,0 +1,19 @@
+bit<4> func1() {
+    bit<4> t = (int)1;
+    return t;
+}
+
+bit<4> func2() {
+    bit<4> t = (bit<4>)(int)(bit<4>)1;
+    return t;
+}
+
+control c(out bit<4> result) {
+    apply {
+        result = func1();
+    }
+}
+control _c(out bit<4> r);
+package top(_c _c);
+
+top(c()) main;

testdata/p4_16_samples_outputs/issue3219-first.p4

@@ -0,0 +1,18 @@
+bit<4> func1() {
+    bit<4> t = (bit<4>)(int)1;
+    return t;
+}
+bit<4> func2() {
+    bit<4> t = (bit<4>)(int)4w1;
+    return t;
+}
+control c(out bit<4> result) {
+    apply {
+        result = func1();
+    }
+}
+
+control _c(out bit<4> r);
+package top(_c _c);
+top(c()) main;
+

testdata/p4_16_samples_outputs/issue3219-frontend.p4

@@ -0,0 +1,17 @@
+control c(out bit<4> result) {
+    @name("c.hasReturned") bool hasReturned;
+    @name("c.retval") bit<4> retval;
+    @name("c.t") bit<4> t_0;
+    apply {
+        hasReturned = false;
+        t_0 = (bit<4>)(int)1;
+        hasReturned = true;
+        retval = t_0;
+        result = retval;
+    }
+}
+
+control _c(out bit<4> r);
+package top(_c _c);
+top(c()) main;
+

testdata/p4_16_samples_outputs/issue3219-midend.p4

@@ -0,0 +1,19 @@
+control c(out bit<4> result) {
+    @hidden action issue3219l13() {
+        result = (bit<4>)(int)1;
+    }
+    @hidden table tbl_issue3219l13 {
+        actions = {
+            issue3219l13();
+        }
+        const default_action = issue3219l13();
+    }
+    apply {
+        tbl_issue3219l13.apply();
+    }
+}
+
+control _c(out bit<4> r);
+package top(_c _c);
+top(c()) main;
+

testdata/p4_16_samples_outputs/issue3219.p4

@@ -0,0 +1,18 @@
+bit<4> func1() {
+    bit<4> t = (int)1;
+    return t;
+}
+bit<4> func2() {
+    bit<4> t = (bit<4>)(int)(bit<4>)1;
+    return t;
+}
+control c(out bit<4> result) {
+    apply {
+        result = func1();
+    }
+}
+
+control _c(out bit<4> r);
+package top(_c _c);
+top(c()) main;
+