[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 Martin Liška changed: What|Removed |Added CC||segher at gcc dot gnu.org Ever confirmed|0 |1 Last reconfirmed||2021-12-13 Status|UNCONFIRMED |NEW
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #1 from Bill Schmidt --- I think that the MMA implementation is incompatible with -mno-fold-gimple. We'll need to prevent that flag combination, I think.
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #2 from Peter Bergner --- (In reply to Bill Schmidt from comment #1) > I think that the MMA implementation is incompatible with -mno-fold-gimple. > We'll need to prevent that flag combination, I think. Does -mno-fold-gimple really even make sense as an option? I agree that the MMA builtins require gimple folding of builtins. One other option is to just ignore rs6000_fold_gimple (true or false) if the builtin attribute has RS6000_BTC_GIMPLE set.
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #3 from Peter Bergner --- Maybe something like this untested patch: diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c index d9736eaf21c..c7babefa32d 100644 --- a/gcc/config/rs6000/rs6000-call.c +++ b/gcc/config/rs6000/rs6000-call.c @@ -13615,12 +13615,14 @@ rs6000_gimple_fold_new_builtin (gimple_stmt_iterator *gsi) const char *fn_name2 = (icode != CODE_FOR_nothing) ? get_insn_name ((int) icode) : "nothing"; + unsigned attr = rs6000_builtin_info[fn_code].attr; if (TARGET_DEBUG_BUILTIN) fprintf (stderr, "rs6000_gimple_fold_new_builtin %d %s %s\n", fn_code, fn_name1, fn_name2); - if (!rs6000_fold_gimple) + if ((attr & RS6000_BTC_GIMPLE) == 0 + && !rs6000_fold_gimple) return false; /* Prevent gimple folding for code that does not have a LHS, unless it is Same thing needs to happen to rs6000_gimple_fold_builtin too
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #4 from Bill Schmidt --- Please don't make changes to the old builtin support, which has been disabled. :-)
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #5 from Bill Schmidt --- More properly, please don't rely on a bit that is being destroyed by the new support. You need to look at built-in function attributes instead.
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #6 from Bill Schmidt --- if (bif_is_mmaint (rs6000_builtin_info_x[uns_fcode]) && !rs6000_fold_gimple) is what you're looking for. However, I would much rather see rejection of the -mno-fold-gimple flag when MMA is enabled. Silently ignoring a flag violates the principle of least astonishment.
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #7 from Richard Biener --- -m[no-]fold-gimple is also a very badly named user option since it suggests that 'fold' and 'gimple' are terms known to programmers. I'm just guessing it was added to avoid "inlining" intrinsics as GIMPLE, so -m[no-]inline-intrinsics would have been more appropriate ;) (or -m[no-]optimize-intrinsics)
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #8 from Segher Boessenkool --- It is an internal (debugging) option. It isn't documented in the manual, but indeed it is not marked as Undocumented in rs6000.opt .
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 Peter Bergner changed: What|Removed |Added CC||willschm at gcc dot gnu.org --- Comment #9 from Peter Bergner --- (In reply to Segher Boessenkool from comment #8) > It is an internal (debugging) option. It isn't documented in the manual, but > indeed it is not marked as Undocumented in rs6000.opt . Will added this and the last time we talked, he said he added it mainly for debugging purposes when he was adding some rs6000 specific gimple builtin expansion code. To his knowledge, we don't need/want this anymore, so I believe the correct fix here is to just remove the option now (assuming it really is undocumented).
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #10 from Bill Schmidt --- It turns out not to be undocumented -- but I'd like to remove it anyway. Any objections?
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #11 from Will Schmidt --- (In reply to Bill Schmidt from comment #10) > It turns out not to be undocumented -- but I'd like to remove it anyway. > Any objections? Realistically I believe I was the only user of that feature, was to help with comparing the before/after codegen for the builtins as I added the gimple folding logic for them. No objections for removal of the option from me. Knowing the history and the compromises involved, at this point I actually encourage the removal of the option. :-) Thanks, -Will
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 --- Comment #12 from CVS Commits --- The master branch has been updated by William Schmidt : https://gcc.gnu.org/g:48bd780ee327c9ae6ffc0641e73cc1f4939fb204 commit r12-7030-g48bd780ee327c9ae6ffc0641e73cc1f4939fb204 Author: Bill Schmidt Date: Wed Feb 2 21:30:27 2022 -0600 rs6000: Remove -m[no-]fold-gimple flag [PR103686] The -m[no-]fold-gimple flag was really intended primarily for internal testing while implementing GIMPLE folding for rs6000 vector built-in functions. It ended up leaking into other places, causing problems such as PR103686 identifies. Let's remove it. There are a number of tests in the testsuite that require adjustment. Some specify -mfold-gimple directly, which is the default, so that is handled by removing the option. Others unnecessarily specify -mno-fold-gimple, as the tests work fine without this. Again that is handled by removing the option. There are a couple of extra variants of tests specifically for -mno-fold-gimple; for those, we can just remove the whole test. gcc.target/powerpc/builtins-1.c was more problematic. It was written in such a way as to be extremely fragile. For this one, I rewrote the whole test in a different style, using individual functions to test each built-in function. These same tests are also largely covered by builtins-1-be-folded.c and builtins-1-le-folded.c, so I chose to explicitly make this test -mbig for simplicity, and use -O2 for clean code generation. I made some slight modifications to the expected instruction counts as a result, and tested on both 32- and 64-bit. 2022-02-02 Bill Schmidt gcc/ PR target/103686 * config/rs6000/rs6000-builtin.cc (rs6000_gimple_fold_builtin): Remove test for !rs6000_fold_gimple. * config/rs6000/rs6000.cc (rs6000_option_override_internal): Likewise. * config/rs6000/rs6000.opt (mfold-gimple): Remove. gcc/testsuite/ PR target/103686 * gcc.target/powerpc/builtins-1-be-folded.c: Remove -mfold-gimple option. * gcc.target/powerpc/builtins-1-le-folded.c: Likewise. * gcc.target/powerpc/builtins-1.c: Rewrite to use small functions and restrict to -O2 -mbig for predictability. Adjust instruction counts. * gcc.target/powerpc/builtins-5.c: Remove -mno-fold-gimple option. * gcc.target/powerpc/p8-vec-xl-xst.c: Likewise. * gcc.target/powerpc/pr83926.c: Likewise. * gcc.target/powerpc/pr86731-nogimplefold-longlong.c: Delete. * gcc.target/powerpc/pr86731-nogimplefold.c: Delete. * gcc.target/powerpc/swaps-p8-17.c: Remove -mno-fold-gimple option.
[Bug target/103686] ICE in rs6000_expand_new_builtin at rs6000-call.c:15946
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103686 Bill Schmidt changed: What|Removed |Added Resolution|--- |FIXED Status|NEW |RESOLVED --- Comment #13 from Bill Schmidt --- Fixed now.
