https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121534
--- Comment #9 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-15 branch has been updated by Vineet Gupta <vine...@gcc.gnu.org>: https://gcc.gnu.org/g:f12a272169523823ff27d69f187f73c4211222ae commit r15-10250-gf12a272169523823ff27d69f187f73c4211222ae Author: Vineet Gupta <vine...@rivosinc.com> Date: Wed Aug 13 20:20:34 2025 -0700 RISC-V: fix __builtin_round clobbering FP exceptions flags [PR121534] __builtin_round() fails to save/restore FP exception flags around the FP compare insn which can potentially clobber the same. Worth noting that the fflags restore bracketing is slightly different than the glibc implementation. Both FLT and FCVT can potentially clobber fflags. gcc generates below where even if branch is not taken and FCVT is not executed, FLT still executed. Thus FSFLAGS is placed AFTER the label 'L3'. glibc implementation FLT can't clobber due to early NaN check, so FSFLAGS can be moved under the branch, before the label. | convert_float_to_float_round | ... | frflags a5 | fabs.s fa5,fa0 | flt.s a4,fa5,fa4 <--- can clobber fflags | beq a4,zero,.L3 | fcvt.w.s a4,fa0,rmm <--- also | fcvt.s.w fa5,a4 | fsgnj.s fa0,fa5,fa0 | .L3: | fsflags a5 <-- both code paths Fixes: f652a35877e3 ("This is almost exclusively Jivan's work....") PR target/121534 gcc/ChangeLog: * config/riscv/riscv.md (round_pattern): save/restore fflags. gcc/testsuite/ChangeLog: * gcc.target/riscv/rvv/autovec/vls/math-nearbyint-1.c: Adjust scan pattern for additional instances of frflags/fsrflags. Signed-off-by: Vineet Gupta <vine...@rivosinc.com>
