Hi! Ping. For convenience, I've re-attached "options: Clarify 'Init' option property usage for streaming optimization". (I've re-verified: "No functional change; no change in generated files.") Grüße Thomas On 2022-03-31T15:22:59+0200, I wrote: > Hi! > > On 2020-11-18T10:36:35+0100, Jakub Jelinek via Gcc-patches wrote: >> Honza mentioned that especially for the new param machinery, most of >> streamed values are probably going to be the default values. Perhaps >> somehow we could stream them more effectively. >> >> This patch implements it and brings further savings, the size >> goes down from 574 bytes to 273 bytes, i.e. less than half. > > Neat idea about the XOR-encoding! > >> Not trying to handle enums because the code doesn't know if (enum ...) 10 >> is even valid, similarly non-parameters because those really generally >> don't have large initializers, and params without Init (those are 0 >> initialized and thus don't need to be handled). > > Given this only looks at 'Init', I understand this may actually > mis-optimize in the case that there is an 'Init' present, but that value > is then "by default" overridden via 'LANG_HOOKS_INIT_OPTIONS_STRUCT', or > 'TARGET_OPTION_OVERRIDE', for example. (I'm however not claiming that's > an actual problem to be worried about -- just for my understanding.) > > Either way: > >> * optc-save-gen.awk: Initialize var_opt_init. In >> cl_optimization_stream_out for params with default values larger than >> 10, xor the default value with the actual parameter value. In >> cl_optimization_stream_in repeat the above xor. > >> --- gcc/optc-save-gen.awk.jj 2020-09-14 10:51:54.493740942 +0200 >> +++ gcc/optc-save-gen.awk 2020-09-14 11:39:39.441602594 +0200 >> @@ -1186,6 +1186,7 @@ for (i = 0; i < n_opts; i++) { >> var_opt_val_type[n_opt_val] = otype; >> var_opt_val[n_opt_val] = "x_" name; >> var_opt_hash[n_opt_val] = flag_set_p("Optimization", flags[i]); >> + var_opt_init[n_opt_val] = opt_args("Init", flags[i]); >> n_opt_val++; >> } >> } > > Reading through the options handling, I was confused why 'Init' needs to > be handled in 'gcc/optc-save-gen.awk'. To help the next person -- like, > me in a few weeks ;-) -- wondering about this, OK to push the attached > "options: Clarify 'Init' option property usage for streaming > optimization"? > > > Grüße > Thomas > > >> @@ -1257,10 +1258,21 @@ for (i = 0; i < n_opt_val; i++) { >> otype = var_opt_val_type[i]; >> if (otype ~ "^const char \\**$") >> print " bp_pack_string (ob, bp, ptr->" name", true);"; >> - else if (otype ~ "^unsigned") >> - print " bp_pack_var_len_unsigned (bp, ptr->" name");"; >> - else >> - print " bp_pack_var_len_int (bp, ptr->" name");"; >> + else { >> + if (otype ~ "^unsigned") { >> + sgn = "unsigned"; >> + } else { >> + sgn = "int"; >> + } >> + if (name ~ "^x_param" && !(otype ~ "^enum ") && var_opt_init[i]) { >> + print " if (" var_opt_init[i] " > (" var_opt_val_type[i] ") 10)"; >> + print " bp_pack_var_len_" sgn " (bp, ptr->" name" ^ " var_opt_init[i] ");"; >> + print " else"; >> + print " bp_pack_var_len_" sgn " (bp, ptr->" name");"; >> + } else { >> + print " bp_pack_var_len_" sgn " (bp, ptr->" name");"; >> + } >> + } >> } >> print " for (size_t i = 0; i < sizeof (ptr->explicit_mask) / sizeof (ptr->explicit_mask[0]); i++)"; >> print " bp_pack_value (bp, ptr->explicit_mask[i], 64);"; >> @@ -1281,10 +1293,18 @@ for (i = 0; i < n_opt_val; i++) { >> print " if (ptr->" name")"; >> print " ptr->" name" = xstrdup (ptr->" name");"; >> } >> - else if (otype ~ "^unsigned") >> - print " ptr->" name" = (" var_opt_val_type[i] ") bp_unpack_var_len_unsigned (bp);"; >> - else >> - print " ptr->" name" = (" var_opt_val_type[i] ") bp_unpack_var_len_int (bp);"; >> + else { >> + if (otype ~ "^unsigned") { >> + sgn = "unsigned"; >> + } else { >> + sgn = "int"; >> + } >> + print " ptr->" name" = (" var_opt_val_type[i] ") bp_unpack_var_len_" sgn " (bp);"; >> + if (name ~ "^x_param" && !(otype ~ "^enum ") && var_opt_init[i]) { >> + print " if (" var_opt_init[i] " > (" var_opt_val_type[i] ") 10)"; >> + print " ptr->" name" ^= " var_opt_init[i] ";"; >> + } >> + } >> } >> print " for (size_t i = 0; i < sizeof (ptr->explicit_mask) / sizeof (ptr->explicit_mask[0]); i++)"; >> print " ptr->explicit_mask[i] = bp_unpack_value (bp, 64);"; ----------------- Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955