On 6/5/25 19:11, Jiawei wrote:
>> Changes since v1:
>> - NFC with attribution to PR/119164 it helps fix and the testcase.
>>
>> 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.
>>
>> Fixes the extraneous FRM read/write in PR119164 (and also PR119832 w/o need
>> for TARGET_MODE_CONFLUENCE). Also reduces the number of FRM writes in
>> SPEC2017 -Ofast -mrv64gcv build significantly.
>>
>> Before After
>> ------------- -------------
>> frrm fsrmi fsrm frrm fsrmi frrm
>
> ~~^~~
>
> Should the second frrm repeat here be fsrm?
>
Yeah sorry this was a typo and indeed reports fsrm.
> Anyway, the results seem to be significantly improved.
>
> LGTM, and thank you for this work.
>
Awesome.
Thx,
-Vineet
>> 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
>> --------------- --------------
>> 7176 3566
>> --------------- --------------
>>
>> PR target/119164
>>
>> gcc/ChangeLog:
>>
>> * config/riscv/riscv.cc (riscv_emit_frm_mode_set): check
>> STATIC_FRM_P for transition to DYN.
>>
>> gcc/testsuite/ChangeLog:
>>
>> * gcc.target/riscv/rvv/base/pr119164.c: New test.
>>
>> Signed-off-by: Vineet Gupta <vine...@rivosinc.com>
>> ---
>> gcc/config/riscv/riscv.cc | 2 +-
>> .../gcc.target/riscv/rvv/base/pr119164.c | 22 +++++++++++++++++++
>> 2 files changed, 23 insertions(+), 1 deletion(-)
>> create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/base/pr119164.c
>>
>> diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
>> index a5f68c999b0e..f982111a9952 100644
>> --- a/gcc/config/riscv/riscv.cc
>> +++ b/gcc/config/riscv/riscv.cc
>> @@ -12182,7 +12182,7 @@ 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)
>> diff --git a/gcc/testsuite/gcc.target/riscv/rvv/base/pr119164.c
>> b/gcc/testsuite/gcc.target/riscv/rvv/base/pr119164.c
>> new file mode 100644
>> index 000000000000..a39a7f177f05
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/riscv/rvv/base/pr119164.c
>> @@ -0,0 +1,22 @@
>> +/* Reduced from SPEC2017 blender: node_texture_util.c.
>> + The conditional function call was tripping mode switching state machine
>> */
>> +
>> +/* { dg-do compile } */
>> +/* { dg-options " -Ofast -march=rv64gcv_zvl256b -ftree-vectorize
>> -mrvv-vector-bits=zvl" } */
>> +
>> +void *a;
>> +float *b;
>> +short c;
>> +void d();
>> +void e() {
>> + if (a)
>> + d();
>> + if (c) {
>> + b[0] = b[0] * 0.5f + 0.5f;
>> + b[1] = b[1] * 0.5f + 0.5f;
>> + }
>> +}
>> +
>> +/* { dg-final { scan-assembler-not {frrm\s+[axs][0-9]+} } } */
>> +/* { dg-final { scan-assembler-not {fsrmi\s+[01234]} } } */
>> +/* { dg-final { scan-assembler-not {fsrm\s+[axs][0-9]+} } } */
>> --
>> 2.43.0
>>
>
>
