On 5/9/25 13:27, Vineet Gupta wrote: > FRM mode switching state machine has DYN as default state which it also > fallsback to after transitioning to other states such as DYN_CALL. > Currently TARGET_MODE_EMIT generates a FRM restore on any transition to > DYN leading to spurious/extraneous FRM restores. > > Only do this if an interim static Rounding Mode was observed in the state > machine. > > This reduces the number of FRM writes in SPEC2017 -Ofast -mrv64gcv build > significantly. > > Before After > ------------- ------------- > frrm fsrmi fsrm frrm fsrmi frrm > perlbench_r 42 0 4 17 0 1 > cpugcc_r 167 0 17 11 0 0 > bwaves_r 16 0 1 16 0 1 > mcf_r 11 0 0 11 0 0 > cactusBSSN_r 76 0 27 19 0 1 > namd_r 119 0 63 14 0 1 > parest_r 168 0 114 24 0 1 > povray_r 123 1 17 26 1 6 > lbm_r 6 0 0 6 0 0 > omnetpp_r 17 0 1 17 0 1 > wrf_r 2287 13 1956 1268 13 1603 > cpuxalan_r 17 0 1 17 0 1 > ldecod_r 11 0 0 11 0 0 > x264_r 14 0 1 11 0 0 > blender_r 724 12 182 61 12 42 > cam4_r 324 13 169 45 13 20 > deepsjeng_r 11 0 0 11 0 0 > imagick_r 265 16 34 132 16 25 > leela_r 12 0 0 12 0 0 > nab_r 13 0 1 13 0 1 > exchange2_r 16 0 1 16 0 1 > fotonik3d_r 20 0 11 19 0 1 > roms_r 33 0 23 21 0 1 > xz_r 6 0 0 6 0 0 > --------------- -------------- > 4498 55 2623 1804 55 1707 > > gcc/ChangeLog: > > * config/riscv/riscv.cc (riscv_emit_frm_mode_set): check > STATIC_FRM_P for trnsition to DYN. > > Signed-off-by: Vineet Gupta <vine...@rivosinc.com> > --- > gcc/config/riscv/riscv.cc | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc > index f1b4b20499fc..37f3ace49a8b 100644 > --- a/gcc/config/riscv/riscv.cc > +++ b/gcc/config/riscv/riscv.cc > @@ -12121,7 +12121,7 @@ riscv_emit_frm_mode_set (int mode, int prev_mode) > && prev_mode != riscv_vector::FRM_DYN > && prev_mode != riscv_vector::FRM_DYN_CALL) > /* Restore frm value when switch to DYN mode. */ > - || (mode == riscv_vector::FRM_DYN > + || (STATIC_FRM_P (cfun) && mode == riscv_vector::FRM_DYN > && prev_mode != riscv_vector::FRM_DYN_CALL); > > if (restore_p)
FWIW this itself (and not 6/6) is sufficient to fix the extraneous FRMs around call insns in PR/119164 and re-fix of PR/119832 (w/o confluence fix) Thx, -Vineet
