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Re: [PATCH] Fix PR tree-optimization/18184 (pointer mode conversions ignored)


Richard Kenner wrote:
> 
>     + 	   && TYPE_MODE (inner_type) == TYPE_MODE (outer_type)
> 
> Don't you also have to compare TYPE_REF_CAN_ALIAS_ALL in all three places too?

I'm not sure.  Conversions between different modes need to be preserved
as we actually need to generate code to implement the conversion.

I don't know what the semantics of a conversion from a pointer with
TYPE_REF_CAN_ALIAS_ALL to an equivalent pointer type without that
flag is (or vice versa).  There's certainly no code generation involved;
and I don't even know for sure whether the TYPE_REF_CAN_ALIAS_ALL flag
needs to be preserved in that situation ...

Do you have an example where this matters?

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  weigand@informatik.uni-erlangen.de


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