https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114044
--- Comment #5 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:c3c44c01d20b00ab5228f32596153b7f4cbc6036 commit r14-9192-gc3c44c01d20b00ab5228f32596153b7f4cbc6036 Author: Jakub Jelinek <ja...@redhat.com> Date: Tue Feb 27 09:52:07 2024 +0100 expand: Add trivial folding for bit query builtins at expansion time [PR114044] While it seems a lot of places in various optimization passes fold bit query internal functions with INTEGER_CST arguments to INTEGER_CST when there is a lhs, when lhs is missing, all the removals of such dead stmts are guarded with -ftree-dce, so with -fno-tree-dce those unfolded ifn calls remain in the IL until expansion. If they have large/huge BITINT_TYPE arguments, there is no BLKmode optab and so expansion ICEs, and bitint lowering doesn't touch such calls because it doesn't know they need touching, functions only containing those will not even be further processed by the pass because there are no non-small BITINT_TYPE SSA_NAMEs + the 2 exceptions (stores of BITINT_TYPE INTEGER_CSTs and conversions from BITINT_TYPE INTEGER_CSTs to floating point SSA_NAMEs) and when walking there is no special case for calls with BITINT_TYPE INTEGER_CSTs either, those are for normal calls normally handled at expansion time. So, the following patch adjust the expansion of these 6 ifns, by doing nothing if there is no lhs, and also just in case and user disabled all possible passes that would fold this handles the case of setting lhs to ifn call with INTEGER_CST argument. 2024-02-27 Jakub Jelinek <ja...@redhat.com> PR rtl-optimization/114044 * internal-fn.def (CLRSB, CLZ, CTZ, FFS, PARITY): Use DEF_INTERNAL_INT_EXT_FN macro rather than DEF_INTERNAL_INT_FN. * internal-fn.h (expand_CLRSB, expand_CLZ, expand_CTZ, expand_FFS, expand_PARITY): Declare. * internal-fn.cc (expand_bitquery, expand_CLRSB, expand_CLZ, expand_CTZ, expand_FFS, expand_PARITY): New functions. (expand_POPCOUNT): Use expand_bitquery. * gcc.dg/bitint-95.c: New test.
