GC: Add i31 instructions (#3154)

Adds the `i31.new` and `i31.get_s/u` instructions for creating and working with `i31ref` typed values. Does not include fuzzer integration just yet because the fuzzer expects that trivial values it creates are suitable in global initializers, which is not the case for trivial `i31ref` expressions.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
index 27c3e327c..ac115edc3 100644
--- a/src/passes/Print.cpp
+++ b/src/passes/Print.cpp
@@ -1474,6 +1474,10 @@ struct PrintExpressionContents
     printMedium(o, "tuple.extract ");
     o << curr->index;
   }
+  void visitI31New(I31New* curr) { printMedium(o, "i31.new"); }
+  void visitI31Get(I31Get* curr) {
+    printMedium(o, curr->signed_ ? "i31.get_s" : "i31.get_u");
+  }
 };
 
 // Prints an expression in s-expr format, including both the
@@ -2063,6 +2067,20 @@ struct PrintSExpression : public OverriddenVisitor<PrintSExpression> {
     printFullLine(curr->tuple);
     decIndent();
   }
+  void visitI31New(I31New* curr) {
+    o << '(';
+    PrintExpressionContents(currFunction, o).visit(curr);
+    incIndent();
+    printFullLine(curr->value);
+    decIndent();
+  }
+  void visitI31Get(I31Get* curr) {
+    o << '(';
+    PrintExpressionContents(currFunction, o).visit(curr);
+    incIndent();
+    printFullLine(curr->i31);
+    decIndent();
+  }
   // Module-level visitors
   void handleSignature(Signature curr, Name* funcName = nullptr) {
     o << "(func";