Oh. It's nice to see you have support min/max index reduction.
I knew your patch can handle this following:
int idx = ii;
int max = mm;
for (int i = 0; i < n; ++i) {
int x = a[i];
if (max < x) {
max = x;
idx = i;
}
}
But I wonder whether your patch can handle this:
int idx = ii;
int max = mm;
for (int i = 0; i < n; ++i) {
int x = a[i];
if (max <= x) {
max = x;
idx = i;
}
}
Will you continue to work on min/max with index ?
Or you want me to continue this work base on your patch ?
I have an initial patch which roughly implemented LLVM's approach but turns out
Richi doesn't want me to apply LLVM's approach so your patch may be more
reasonable than LLVM's approach.
Thanks.
juzhe.zh...@rivai.ai
From: Tamar Christina
Date: 2024-01-09 01:50
To: 钟居哲; gcc
CC: rdapp.gcc; richard.guenther
Subject: RE: Loop vectorizer optimization questions
>
> Also, another question is that I am working on min/max reduction with index, I
> believe it should be in GCC-15, but I wonder
> whether I can pre-post for review in stage 4, or I should post patch (min/max
> reduction with index) when GCC-15 is open.
>
FWIW, We tried to implement this 5 years ago
https://gcc.gnu.org/pipermail/gcc-patches/2019-November/534518.html
and you'll likely get the same feedback if you aren't already doing so.
I think Richard would prefer to have a general framework these kinds of
operations. We never got around to doing so
and it's still on my list but if you're taking care of it
Just though I'd point out the previous feedback.
Cheers,
Tamar
> Thanks.
>
>
> juzhe.zh...@rivai.ai
