https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100212
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Andrew Pinski <pins...@gcc.gnu.org>: https://gcc.gnu.org/g:0c2583dc2575f3f64e3d09e12c296eb56f01916d commit r14-8441-g0c2583dc2575f3f64e3d09e12c296eb56f01916d Author: Andrew Pinski <quic_apin...@quicinc.com> Date: Thu Jan 25 13:45:59 2024 -0800 aarch64: Fix/avoid undefinedness in aarch64_classify_index [PR100212] The problem here is we don't check the return value of exact_log2 and always use that result as shifter. This fixes the issue by avoiding the shift if the value was `-1` (which means the value was not exact a power of 2); in this case we could either check if the values was equal to -1 or not equal to because we then assign -1 to shift if the constant value was not equal. I chose `!=` as it seemed to be more obvious of what the code is doing. Committed as obvious after a build/test for aarch64-linux-gnu. gcc/ChangeLog: PR target/100212 * config/aarch64/aarch64.cc (aarch64_classify_index): Avoid undefined shift after the call to exact_log2. Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
