On Tue, Aug 30, 2016 at 7:17 AM, Segher Boessenkool <seg...@kernel.crashing.org> wrote: > The exit block (to which every return artificially jumps) already has > a use of LR. The LR use in all returns and sibcalls is an anachronism, > probably made unnecessary by the dataflow merge. The simple_returns > that shrink-wrapping generates also do not have such a use. Newer > backends do not do this either it seems. > > With this use removed, a normal return is no longer a parallel but just > a return insn, and cfgcleanup then can transform conditional jumps to > those into conditional returns. > > This splits the return emission code with restoring_FPRs_inline from > that without it; this is simpler code, fewer lines, and less indentation. > > The return_internal_<mode> pattern can now be deleted since nothing uses > it anymore. > > Tested on powerpc64-linux (-m32,-m64); will test on powerpc64le-linux > as well. David and Iain, can you please test on AIX and Darwin? > > Or is this okay for trunk without testing? ;-) > > > Segher > > > 2016-08-30 Segher Boessenkool <seg...@kernel.crashing.org> > > * config/rs6000/rs6000.c (rs6000_emit_epilogue): Do not emit > USEs of LR_REGNO in returns and sibcalls. > (rs6000_output_mi_thunk): Similar. > (rs6000_sibcall_aix): Similar. > * config/rs6000/rs6000.md (sibcall, sibcall_value, sibcall_local32, > sibcall_local64, sibcall_value_local32, sibcall_value_local64, > sibcall_nonlocal_sysv<mode>, sibcall_value_nonlocal_sysv<mode>): > Remove the USE of LR_REGNO from the patterns as well. Delete an > obsolete comment. > (return_internal_<mode>): Delete.
This is okay. PPC64 BE Linux uses ABI_AIX, so that AIX logic should be okay. Thanks, David
