Question on C1's as_ValueType(ciConstant value)

Roland Westrelin roland.westrelin at oracle.com
Tue Jun 9 10:49:22 UTC 2015


Hi Kris,

> 145 ValueType* as_ValueType(ciConstant value) {
> 146   switch (value.basic_type()) {
> 147     case T_BYTE   : // fall through
> 148     case T_CHAR   : // fall through
> 149     case T_SHORT  : // fall through
> 150     case T_BOOLEAN: // fall through
> 151     case T_INT    : return new IntConstant   (value.as_int   ());
> 152     case T_LONG   : return new LongConstant  (value.as_long  ());
> 153     case T_FLOAT  : return new FloatConstant (value.as_float ());
> 154     case T_DOUBLE : return new DoubleConstant(value.as_double());
> 155     case T_ARRAY  : // fall through (ciConstant doesn't have an array accessor)
> 156     case T_OBJECT : return new ObjectConstant(value.as_object());
> 157   }
> 158   ShouldNotReachHere();
> 159   return illegalType;
> 160 }
> 
> On lines 155 and 156, both basic types T_ARRAY and T_OBJECT turns into a ObjectConstant.
> That's not consistent with the handling in GraphKit::load_constant(), where ArrayConstant, InstanceConstant and ObjectConstant are treated separately.
> 
> I ran into this inconsistency when I wanted to try out something with array constants. But I was only able to reach the constant from an ObjectConstant, instead of an ArrayConstant like I was expecting.
> 
> If people agree that this inconsistency should be fixed, I'd be happy to provide a patch and test it.

Strange inconsistency indeed. I think it makes sense to fix this. Please go ahead with the patch. I’ll sponsor it.

Roland.


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