On 06/12/2011 06:59 AM, Richard Guenther wrote:
The please provide a specification on what a VIEW_CONVERT_EXPR does to type-based alias analysis.
If the alias set of the VIEW_CONVERT_EXPR type the same as the set for the operand, ignore it; if it's a subset, handle it like a COMPONENT_REF; otherwise ignore the operand for TBAA.
It seems like get_alias_set currently gets this backwards; it's ignoring outer COMPONENT_REFs instead of the inner structure.
Yes, we do handle lvalue VIEW_CONVERT_EXPRs, but that is for Ada which uses it for aggregates.
It also seems to be widely used for vectors, but perhaps that's only for rvalues.
I don't want us to add more lvalue VIEW_CONVERT_EXPR cases, especially not for register types.
Then how do we convert an int lvalue to a volatile int lvalue?
/* Represents viewing something of one type as being of a second type. This corresponds to an "Unchecked Conversion" in Ada and roughly to the idiom *(type2 *)&X in C.
Right, that's why I thought it was an lvalue.
This code may also be used within the LHS of a MODIFY_EXPR
And this. Jason
