Hi Richard,
On 6 September 2016 at 19:57, Richard Biener <richard.guent...@gmail.com> wrote: > On Tue, Sep 6, 2016 at 11:33 AM, Kugan Vivekanandarajah > <kugan.vivekanandara...@linaro.org> wrote: >> Hi Richard, >> >> On 6 September 2016 at 19:08, Richard Biener <richard.guent...@gmail.com> >> wrote: >>> On Tue, Sep 6, 2016 at 2:24 AM, Kugan Vivekanandarajah >>> <kugan.vivekanandara...@linaro.org> wrote: >>>> Hi Richard, >>>> >>>> On 5 September 2016 at 17:57, Richard Biener <richard.guent...@gmail.com> >>>> wrote: >>>>> On Mon, Sep 5, 2016 at 7:26 AM, Kugan Vivekanandarajah >>>>> <kugan.vivekanandara...@linaro.org> wrote: >>>>>> Hi All, >>>>>> >>>>>> While looking at gcc source, I noticed that we are iterating over SSA >>>>>> variable from 0 to num_ssa_names in some cases and 1 to num_ssa_names >>>>>> in others. It seems that variable 0 is always NULL TREE. >>>>> >>>>> Yeah, that's artificial because we don't assign SSA name version 0 (for >>>>> some >>>>> unknown reason). >>>>> >>>>>> But it can >>>>>> confuse people who are looking for the first time. Therefore It might >>>>>> be good to follow some consistent usage here. >>>>>> >>>>>> It might be also good to gave a FOR_EACH_SSAVAR iterator as we do in >>>>>> other case. Here is attempt to do this based on what is done in other >>>>>> places. Bootstrapped and regression tested on X86_64-linux-gnu with no >>>>>> new regressions. is this OK? >>>>> >>>>> First of all some bikeshedding - FOR_EACH_SSA_NAME would be better >>>>> as SSAVAR might be confused with iterating over SSA_NAME_VAR. >>>>> >>>>> Then, if you add an iterator why leave the name == NULL handling to >>>>> consumers? >>>>> That looks odd. >>>>> >>>>> Then, SSA names are just in a vector thus why not re-use the vector >>>>> iterator? >>>>> >>>>> That is, >>>>> >>>>> #define FOR_EACH_SSA_NAME (name) \ >>>>> for (unsigned i = 1; SSANAMES (cfun).iterate (i, &name); ++i) >>>>> >>>>> would be equivalent to your patch? >>>>> >>>>> Please also don't add new iterators that implicitely use 'cfun' but >>>>> always use >>>>> one that passes it as explicit arg. >>>> >>>> I think defining FOR_EACH_SSA_NAME with vector iterator is better. But >>>> we will not be able to skill NULL ssa_names with that. >>> >>> Why? Can't you simply do >>> >>> #define FOR_EACH_SSA_NAME (name) \ >>> for (unsigned i = 1; SSANAMES (cfun).iterate (i, &name); ++i) \ >>> if (name) >>> >>> ? >> >> For example, with the test patch where loop body also defines i which >> is giving error: >> >> ../../trunk/gcc/tree-ssa-ter.c: In function ‘temp_expr_table* >> new_temp_expr_table(var_map)’: >> ../../trunk/gcc/tree-ssa-ter.c:206:11: error: redeclaration of ‘int i’ >> int i; >> ^ >> In file included from ../../trunk/gcc/ssa.h:29:0, >> from ../../trunk/gcc/tree-ssa-ter.c:28: >> ../../trunk/gcc/tree-ssanames.h:66:17: note: ‘unsigned int i’ >> previously declared here >> for (unsigned i = 1; SSANAMES (cfun)->iterate (i, &VAR); ++i) >> ^ >> ../../trunk/gcc/tree-ssa-ter.c:204:3: note: in expansion of macro >> ‘FOR_EACH_SSA_NAME’ >> FOR_EACH_SSA_NAME (name) >> ^ >> Makefile:1097: recipe for target 'tree-ssa-ter.o' failed >> >> Am I missing something here ? > > Well, my comment was not about passing 'i' to the macro but about > not being able to skip NULL names. I just copied & pasted my > earlier macro. Sorry, I misunderstood your comment. I have: +#define FOR_EACH_SSA_NAME(i, VAR) \ + for (i = 1; SSANAMES (cfun)->iterate (i, &VAR); ++i) We will skip the first (0 index) if that is what you are referring here. I also thought that you wanted to skip any NULL_TREEs after that too. After looking at your previous your comment, I don’t you think you wanted that anyway. Therefore I think I am doing what you wanted in my last patch. Thanks, Kugan > Richard. > >> Thanks, >> Kugan >> >>> >>>> I also added >>>> index variable to the macro so that there want be any conflicts if the >>>> index variable "i" (or whatever) is also defined in the loop. >>>> >>>> Bootstrapped and regression tested on x86_64-linux-gnu with no new >>>> regressions. Is this OK for trunk? >>>> >>>> Thanks, >>>> Kugan >>>> >>>> >>>> gcc/ChangeLog: >>>> >>>> 2016-09-06 Kugan Vivekanandarajah <kug...@linaro.org> >>>> >>>> * tree-ssanames.h (FOR_EACH_SSA_NAME): New. >>>> * cfgexpand.c (update_alias_info_with_stack_vars): Use >>>> FOR_EACH_SSA_NAME to iterate over SSA variables. >>>> (pass_expand::execute): Likewise. >>>> * omp-simd-clone.c (ipa_simd_modify_function_body): Likewise. >>>> * tree-cfg.c (dump_function_to_file): Likewise. >>>> * tree-into-ssa.c (pass_build_ssa::execute): Likewise. >>>> (update_ssa): Likewise. >>>> * tree-ssa-alias.c (dump_alias_info): Likewise. >>>> * tree-ssa-ccp.c (ccp_finalize): Likewise. >>>> * tree-ssa-coalesce.c (build_ssa_conflict_graph): Likewise. >>>> (create_outofssa_var_map): Likewise. >>>> (coalesce_ssa_name): Likewise. >>>> * tree-ssa-operands.c (dump_immediate_uses): Likewise. >>>> * tree-ssa-pre.c (compute_avail): Likewise. >>>> * tree-ssa-sccvn.c (init_scc_vn): Likewise. >>>> (scc_vn_restore_ssa_info): Likewise. >>>> (free_scc_vn): Likwise. >>>> (run_scc_vn): Likewise. >>>> * tree-ssa-structalias.c (compute_points_to_sets): Likewise. >>>> * tree-ssa-ter.c (new_temp_expr_table): Likewise. >>>> * tree-ssa-copy.c (fini_copy_prop): Likewise. >>>> * tree-ssa.c (verify_ssa): Likewise. >>>> >>>>> >>>>> Thanks, >>>>> Richard. >>>>> >>>>> >>>>>> Thanks, >>>>>> Kugan >>>>>> >>>>>> >>>>>> gcc/ChangeLog: >>>>>> >>>>>> 2016-09-05 Kugan Vivekanandarajah <kug...@linaro.org> >>>>>> >>>>>> * tree-ssanames.h (ssa_iterator::ssa_iterator): New. >>>>>> (ssa_iterator::get): Likewise. >>>>>> (ssa_iterator::next): Likewise. >>>>>> (FOR_EACH_SSAVAR): Likewise. >>>>>> * cfgexpand.c (update_alias_info_with_stack_vars): Use >>>>>> FOR_EACH_SSAVAR to iterate over SSA variables. >>>>>> (pass_expand::execute): Likewise. >>>>>> * omp-simd-clone.c (ipa_simd_modify_function_body): Likewise. >>>>>> * tree-cfg.c (dump_function_to_file): Likewise. >>>>>> * tree-into-ssa.c (pass_build_ssa::execute): Likewise. >>>>>> (update_ssa): Likewise. >>>>>> * tree-ssa-alias.c (dump_alias_info): Likewise. >>>>>> * tree-ssa-ccp.c (ccp_finalize): Likewise. >>>>>> * tree-ssa-coalesce.c (build_ssa_conflict_graph): Likewise. >>>>>> (create_outofssa_var_map): Likewise. >>>>>> (coalesce_ssa_name): Likewise. >>>>>> * tree-ssa-operands.c (dump_immediate_uses): Likewise. >>>>>> * tree-ssa-pre.c (compute_avail): Likewise. >>>>>> * tree-ssa-sccvn.c (init_scc_vn): Likewise. >>>>>> (scc_vn_restore_ssa_info): Likewise. >>>>>> (free_scc_vn): Likwise. >>>>>> (run_scc_vn): Likewise. >>>>>> * tree-ssa-structalias.c (compute_points_to_sets): Likewise. >>>>>> * tree-ssa-ter.c (new_temp_expr_table): Likewise.
