[Bug tree-optimization/95771] Failure to optimize popcount idiom when argument is unsigned char
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95771 --- Comment #3 from Jakub Jelinek --- Should be fixed now, except that for __uint128_t we aren't able to optimize away the conditional in if (x) return __builtin_popcountll (x >> 64) + __builtin_popcountll (x); else return 0; - the phiopt popcount/clz/ctz conditional removal isn't able to deal with the two popcounts added + shift and cast.
[Bug tree-optimization/95771] Failure to optimize popcount idiom when argument is unsigned char
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95771 --- Comment #2 from CVS Commits --- The master branch has been updated by Jakub Jelinek : https://gcc.gnu.org/g:24cd9afe617a39801d190418cf3fbab3bc3742a7 commit r11-6443-g24cd9afe617a39801d190418cf3fbab3bc3742a7 Author: Jakub Jelinek Date: Mon Jan 4 14:36:06 2021 +0100 loop-niter: Recognize popcount idioms even with char, short and __int128 [PR95771] As the testcase shows, we punt unnecessarily on popcount loop idioms if the type is smaller than int or larger than long long. Smaller type than int can be handled by zero-extending the argument to unsigned int, and types twice as long as long long by doing __builtin_popcountll on both halves of the __int128. 2020-01-04 Jakub Jelinek PR tree-optimization/95771 * tree-ssa-loop-niter.c (number_of_iterations_popcount): Handle types with precision smaller than int's precision and types with precision twice as large as long long. Formatting fixes. * gcc.target/i386/pr95771.c: New test.
[Bug tree-optimization/95771] Failure to optimize popcount idiom when argument is unsigned char
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95771 Jakub Jelinek changed: What|Removed |Added Status|UNCONFIRMED |ASSIGNED Assignee|unassigned at gcc dot gnu.org |jakub at gcc dot gnu.org Ever confirmed|0 |1 Last reconfirmed||2021-01-02 --- Comment #1 from Jakub Jelinek --- Created attachment 49868 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49868=edit gcc11-pr95771.patch Untested fix.
