On Tue, Oct 14, 2025 at 2:51 PM ywgrit <[email protected]> wrote: > > > > Richard Biener <[email protected]> 于2025年10月14日周二 20:31写道： >> >> On Tue, Oct 14, 2025 at 2:22 PM ywgrit <[email protected]> wrote: >> > >> > A program may consist of multiple compilation units, and multiple array >> > access operations may exist within the program. >> > In SIMPLE_IPA_PASS, I want to check whether the index is consistent during >> > two array accesses: During the first pass through all functions, traverse >> > all gimples, record each array access operation, and store its >> > corresponding {Function *, index} into a hash_set. During the second pass >> > through all functions, when encountering the array access operation we >> > wish to process, search for {Function *, index} in the hash_set. >> > Converting SIMPLE_IPA_PASS to IPA_PASS presents challenges. >> > Since Function * is a pointer, direct transfer is meaningless. index is an >> > ssa_name, so direct transfer is also impossible. My question is: Since the >> > above approach fails, if I encounter an array access operation during the >> > wpa phase, how should I determine whether there exists another array >> > access operation within the same function that shares the same index? >> >> You have to split the pass into local analysis pre-WPA which would >> need to compute this (while it has access >> to the body of the function) a "merge" operation during WPA and a >> transform during LTRANS. > > Is pre-WPA the generate phase?
LGEN, yes. >> Note >> that comparing SSA names itself between functions is meaningless, > > Is this because ssa_name is bound to the function? i.e., > function->gimple_df->ssaname. Because they are function-local entities, yes. >> I'm >> guessing you want to >> compute the array access index based on function parameters? >> > When I encounter an array access, assuming this array access occurs within > function func_a, I want to know if there are other array accesses with the > same index within func_a. OK, but how does IPA come into play here? You can do this fully local, for example as said during LGEN. Richard. >> >> Richard, >> >> > Thanks. >> > >> > ywgrit. >> > >> > Richard Biener <[email protected]> 于2025年10月13日周一 14:42写道： >> >> >> >> On Sat, Oct 11, 2025 at 10:32 AM ywgrit via Gcc <[email protected]> wrote: >> >> > >> >> > I used the functions stream_write_tree/stream_read_tree in lto. If tree >> >> > contains ssa_name, then stream_read_tree will generate ice: cfun is >> >> > null in >> >> > wpa, so (*SSANAMES (cfun))[ix] will break the program. How to write/read >> >> > tree contains ssa_name in lto, e.g., wpa phase? >> >> >> >> You shouldn't - you have to abstract from this somehow as during WPA phase >> >> a SSA name doesn't make "sense". That said, you have to elaborate a bit >> >> on >> >> what you are trying to do. >> >> >> >> Richard. >> >> >> >> > Thanks. >> >> > >> >> > ywgrit. > > Thanks. > > ywgrit.
