Ping. Could please someone check if my approach is OK and it is worth to continue work on patch for PR50038?
Thanks Ilya 2011/10/11 Ilya Enkovich <enkovich....@gmail.com>: > 2011/10/4 Richard Henderson <r...@redhat.com>: >> On 10/04/2011 08:42 AM, Joseph S. Myers wrote: >>> On Tue, 4 Oct 2011, Ilya Tocar wrote: >>> >>>> Hi everyone, >>>> >>>> This patch fixes PR 50038 (redundant zero extensions) by modifying >>>> implicit-zee pass >>>> to also remove unneeded zero extensions from QImode to SImode. >>> >>> Hardcoding particular modes like this in the target-independent parts of >>> the compiler is fundamentally ill-conceived. Right now it hardcodes the >>> (SImode, DImode) pair. You're adding hardcoding of (QImode, SImode) as >>> well. But really it should consider all pairs of (integer mode, wider >>> integer mode), with the machine description (or target hooks) determining >>> which pairs are relevant on a particular target. Changing it not to >>> hardcode particular modes would be better than adding a second pair. >>> >> >> That along with not hard-coding ZERO_EXTEND. >> >> Both MIPS and Alpha have much the same free operations, but with SIGN_EXTEND. >> >> I remember rejecting one iteration of this pass with this hard-coded, but the >> pass was apparently approved by someone else without that being corrected. >> >> >> r~ >> > > Hello guys, > > Could you please look at my patch version? I tried to remove all > unnecessary mode restrictions and cover SIGN_EXTEND case. I did not > test this patch yet, just checked it worked on reproducer from > PR50038. > > Thanks > Ilya > --- > gcc/ > > * implicit-zee.c (ext_cand): New. > (ext_cand_pool): Likewise. > (add_ext_candidate): Likewise. > (zee_init): Likewise. > (zee_cleanup): Likewise. > (combine_set_zero_extend): Get extend candidate as new parameter. > Now handle sign extend cases and all modes. > (transform_ifelse): Likewise. > (merge_def_and_ze): Likewise. > (combine_reaching_defs): Change parameter type. > (zero_extend_info): Changed insn_list type. > (add_removable_zero_extend): Relaxed mode and code filter. > (find_removable_zero_extends): Changed return type. > (find_and_remove_ze): Var type changes. > (rest_of_handle_zee): Initialization and cleanup added. >
