See http://cr.openjdk.java.net/~thartmann/talks/2019-ValueType_Optimizations.pdf

The verified_entry and verified_value_ro_entry of a C1-compiled method may need to extend the stack. On x64, this happens when some incoming scalarized parameters are passed in XMM registers. E.g.,

    static value class FloatPoint {
        final float x;
        final float y;
        public FloatPoint(float x, float y) {
            this.x = x;
            this.y = y;
        }
    }
    @ForceCompile(compLevel = C1)
    private static float test43_helper(FloatPoint fp, int a1, int a2, int a3, int a4, int a5, int a6) {
        // On x64:
        // Scalarized entry -- all parameters are passed in registers
        // Non-scalarized entry -- a6 is passed on stack[0]
        return fp.x + fp.y + a1 + a2 + a3 + a4 + a5 + a6;
    }

We need to save the stack extension amount (0x10 bytes in this case) in the stack, and change the return code sequence from

   pop %rbp
   retq

to this:

    mov 0x10(%rsp),%rbp ; restore rbp
    add 0x8(%rsp),%rsp ; repair stack
    retq