Note it's not quite "whatever" -- there is a constraint that vl be
monotonically nonincreasing, which in some cases is the only important
property. No denying this is an annoyance, though.
Yes, I was hoping the smiley would convey that "whatever" was not to be taken
literally. In terms of SC
On Mon, Mar 31, 2025 at 11:34 PM Robin Dapp wrote:
>
> >> Yeah...and I also don't like the magic "ceil(AVL / 2) ≤ vl ≤ VLMAX if
> >> AVL < (2 * VLMAX)" rule...
> >
> > +1, spec has some description about this but I am not sure if I really get
> > the point.
> >
> > From Spec:
> >
> > "For exampl
Yeah...and I also don't like the magic "ceil(AVL / 2) ≤ vl ≤ VLMAX if
AVL < (2 * VLMAX)" rule...
+1, spec has some description about this but I am not sure if I really get the
point.
From Spec:
"For example, this permits an implementation to set vl = ceil(AVL
/ 2) for VLMAX <
Kito Cheng
Sent: Tuesday, April 1, 2025 9:53 AM
To: Robin Dapp
Cc: Kito Cheng ; gcc-patches@gcc.gnu.org;
pal...@dabbelt.com; jeffreya...@gmail.com; rd...@ventanamicro.com;
juzhe.zh...@rivai.ai; Li, Pan2 ; vine...@rivosinc.com;
patr...@rivosinc.com; monk.chi...@sifive.com
Subject: Re: [PATCH v3
Hi Robin:
Pushed to trunk, thanks,
On Mon, Mar 31, 2025 at 11:23 PM Robin Dapp wrote:
>
> LGTM (even though I still don't like the spec :D).
Yeah...and I also don't like the magic "ceil(AVL / 2) ≤ vl ≤ VLMAX if
AVL < (2 * VLMAX)" rule...
> We still have an implicit assumption in riscv-vsetvl.
From: Monk Chiang
According to Section 3.4.2, Vector Register Grouping, in the RISC-V
Vector Specification, the rule for LMUL is LMUL >= SEW/ELEN
Changes since V2:
- Add check on vector-iterators.md
- Add one more testcase to check the VLS use correct mode.
gcc/ChangeLog:
* config/riscv
LGTM (even though I still don't like the spec :D).
We still have an implicit assumption in riscv-vsetvl.cc that might modify LMUL:
In prev_ratio_valid_for_next_sew_p and next_ratio_valid_for_prev_sew_p we check
whether the ratio of two LMULs is <= 8. ISTR that with recent changes we only
re-u
