On Thu, 17 Dec 2015, Yury Gribov wrote: > On 12/17/2015 02:59 PM, Richard Biener wrote: > > On Thu, 17 Dec 2015, Yury Gribov wrote: > > > > > On 12/17/2015 02:41 PM, Richard Biener wrote: > > > > On Thu, 17 Dec 2015, Yury Gribov wrote: > > > > > > > > > Some obvious symmetry fixes. > > > > > > > > > > Cc-ing > > > > > * Andrey (Belevantsev) for bb_top_order_comparator > > > > > * Andrew (MacLeod) for compare_case_labels > > > > > * Andrew (Pinski) for resort_field_decl_cmp > > > > > * Diego for pair_cmp > > > > > * Geoff for resort_method_name_cmp > > > > > * Jakub for compare_case_labels > > > > > * Jason for method_name_cmp > > > > > * Richard for insert_phi_nodes_compare_var_infos, compare_case_labels > > > > > * Steven for cmp_v_in_regset_pool > > > > > > > > So for compare_case_labels we only ever have one label with > > > > !CASE_LOW - which means you only run into the case that needs > > > > !CASE_LOW && !CASE_LOW if comparing an element with itself, correct? > > > > > > > > In this case (missing "same element" handling rather than symmetry > > > > fixing) I'd prefer a > > > > > > > > if (case1 == case2) > > > > return 0; > > > > > > > > So just to confirm - do the patches also contain same element > > > > compare fixings? > > > > > > Yes, that's a fix for same element. How about adding if + gcc_assert that > > > both cases can't be NULL otherwise? > > > > Well, does qsort require the compare function to result in zero > > for same elements when the sequence to be sorted doesn't contain > > duplicates? > > Sure, that's part of total ordering requirement in standard. > > > If an assert works for you that hints at these places found via static > > analysis rather than a runtime fuzzer? > > Sorry, not sure I fully understood but - yes, adding assertion would typically > allow for better checking by static analyzers.
The question was if you actually observed the case to happen with a testcase (and whatever mungled qsort implementation) or whether it was a theoretical outcome computed by a static analyzer. That is, whether you could hand me a testcase where it happens or not. Richard.
