https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87832
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Alexander Monakov <amona...@gcc.gnu.org>: https://gcc.gnu.org/g:dd744f06c9952f92738b0860630085f0f0b99574 commit r13-4092-gdd744f06c9952f92738b0860630085f0f0b99574 Author: Alexander Monakov <amona...@ispras.ru> Date: Tue Nov 1 17:04:25 2022 +0300 i386: correct x87&SSE division modeling in znver.md Correct modeling of division instructions in the SIMD/FP domain for AMD Zen architectures and avoid combinatorial explosion of automaton tables by modeling the separate floating-point division unit and correcting reservations to reflect reciprocal throughput of the corresponding instructions, similar to earlier commit 5cee5f94000 ("i386: correct integer division modeling in znver.md"). Division is partially pipelined and some instructions have fractional throughput (e.g. Zen 3 can issue divss and divsd each 3.5 and 4.5 cycles on average, respectively). Considering these CPUs implement out-of-order execution, the model doesn't need to be exact to the last cycle, so simplify it by using 4/5 cycles for SF/DF modes, and not modeling the fact that FP3 pipe is occupied for one cycle. Top znver table sizes in insn-automata.o: Before: 428108 r znver1_fp_min_issue_delay 856216 r znver1_fp_transitions After: 30056 r znver1_fp_min_issue_delay 120224 r znver1_fp_transitions gcc/ChangeLog: PR target/87832 * config/i386/znver.md (znver1_fdiv): New automaton. (znver1-fdiv): New unit. (znver1_fp_op_div): Correct unit and cycles in the reservation. (znver1_fp_op_div_load): Ditto. (znver1_fp_op_idiv_load): Ditto. (znver2_fp_op_idiv_load): Ditto. (znver1_ssediv_ss_ps): Ditto. (znver1_ssediv_ss_ps_load): Ditto. (znver1_ssediv_sd_pd): Ditto. (znver1_ssediv_sd_pd_load): Ditto. (znver1_ssediv_avx256_ps): Ditto. (znver1_ssediv_avx256_ps_load): Ditto. (znver1_ssediv_avx256_pd): Ditto. (znver1_ssediv_avx256_pd_load): Ditto.