[LLVMdev] target specific ways to extend ConstantExpr

[Eli Friedman]

On Mon, Dec 17, 2012 at 5:10 PM, Yuan Lin <yulin at nvidia.com> wrote:
> We cannot use bitcast because bitcast is a value preserving operation, but
> the address space conversion operation we have is a bit-changing operation.
>
>
>
> Where will the bulk of work be? Can we make a ConstantExpr which has a new
> Opcode (or reuse call) and a list of operands? The first operand is a
> string.

I would suggest adding a new subclass to Constant; that's closer to
the direction we want to be moving in.  It'll look somewhat similar to
ConstantExpr, but you don't want to mess with the opcodes ConstantExpr
uses, and messing with the existing ConstantExpr code to allow
MDStrings as operands would probably be harder than writing a class
from scratch.

-Eli