diff --git a/src/mapleall/maple_ir/src/mir_type.cpp b/src/mapleall/maple_ir/src/mir_type.cpp
index 0436fd7469e36ba8c6f874fa80f8ce062f24266d..fb730cf6d14895f5a1ff878b4f43e11573459315 100644
--- a/src/mapleall/maple_ir/src/mir_type.cpp
+++ b/src/mapleall/maple_ir/src/mir_type.cpp
@@ -178,11 +178,11 @@ bool IsNoCvtNeeded(PrimType toType, PrimType fromType) {
     case PTY_i8:
     case PTY_i16:
       return fromType == PTY_i32;
+    case PTY_i64:
     case PTY_u64:
     case PTY_a64:
-      return fromType == PTY_ptr;
     case PTY_ptr:
-      return fromType == PTY_u64 || fromType == PTY_a64;
+      return fromType == PTY_ptr || fromType == PTY_u64 || fromType == PTY_a64 || fromType == PTY_i64;
     default:
       return false;
   }
diff --git a/src/mapleall/mpl2mpl/src/constantfold.cpp b/src/mapleall/mpl2mpl/src/constantfold.cpp
index 8da165aff49e5c138a9c90e0ba3181feedfcaaea..48bfa4752098b31188706f7b65222fd52dc5e97d 100644
--- a/src/mapleall/mpl2mpl/src/constantfold.cpp
+++ b/src/mapleall/mpl2mpl/src/constantfold.cpp
@@ -1688,10 +1688,13 @@ std::pair<BaseNode*, int64> ConstantFold::FoldBinary(BinaryNode *node) {
       result = l;
       sum = lp.second + cst;
     } else if (op == OP_sub) {
+#if 0  // this is preventing good optimizations
       if (IsSignedInteger(primType) && MinValOfSignedInteger(primType) <= cst) {
         result = node;
         sum = 0;
-      } else {
+      } else 
+#endif
+      {
         result = l;
         sum = lp.second - cst;
       }