src/hotspot/share/adlc/formsopt.cpp

@@ -169,13 +169,17 @@
    // The array of Register Mask bits should be large enough to cover
    // all the machine registers and all parameters that need to be passed
    // on the stack (stack registers) up to some interesting limit.  Methods
    // that need more parameters will NOT be compiled.  On Intel, the limit
    // is something like 90+ parameters.
-   // Add a few (3 words == 96 bits) for incoming & outgoing arguments to calls.
-   // Round up to the next doubleword size.
-   return (words_for_regs + 3 + 1) & ~1;
+   // - Add a few (3 words == 96 bits) for incoming & outgoing arguments to
+   //   calls.
+   // - Round up to the next doubleword size.
+   // - Add one more word to accommodate a reasonable number of stack locations
+   //   in the register mask regardless of how much slack is created by rounding.
+   //   This was found necessary after adding 16 new registers for APX.
+   return (words_for_regs + 3 + 1 + 1) & ~1;
  }
  
  void RegisterForm::dump() {                  // Debug printer
    output(stderr);
  }