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Re: PATCH to gimplify_modify_expr to avoid extra copies


On Thu, Jun 10, 2004 at 11:27:25PM -0400, Jason Merrill wrote:
> ! 	  /* Use a V_MAY_DEF if the RHS might throw, as the LHS won't be
> ! 	     modified in that case.  FIXME we should represent somehow
> ! 	     that it is killed on the fallthrough path.  */
> ! 	  || TREE_CODE (TREE_OPERAND (stmt, 1)) == CALL_EXPR
> ! 	  || (flag_non_call_exceptions
> ! 	      && tree_could_trap_p (TREE_OPERAND (stmt, 1))))

After gimplification, we can do better than this; use tree_could_throw_p.

Hmm, I see we currently only use this on complete statements.  There's a
bug here for expressions -- the final return should be checking
tree_could_trap_p.


r~


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