Hi! On Mon, Sep 17, 2018 at 11:11:53AM +0200, Eric Botcazou wrote: > more precisely, to a nested function that requires a static chain. The > reason > is that the sibling call epilogue may clobber the static chain register r11. > > Tested on PowerPC/Linux, OK for the mainline? > > > 2018-09-17 Eric Botcazou <ebotca...@adacore.com> > > * config/rs6000/rs6000.c (rs6000_function_ok_for_sibcall): Return false > if the call takes a static chain.
> --- config/rs6000/rs6000.c (revision 264342) > +++ config/rs6000/rs6000.c (working copy) > @@ -24332,6 +24332,10 @@ rs6000_function_ok_for_sibcall (tree dec > { > tree fntype; > > + /* The sibcall epilogue may clobber the static chain register. */ > + if (CALL_EXPR_STATIC_CHAIN (exp)) > + return false; > + > if (decl) > fntype = TREE_TYPE (decl); > else We could probably make sibcalls work with static chain, but that is most likely not worth it. Could you change the comment to say something like that? Approved for trunk and backports. Thanks! Segher