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From: "yyc1992 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug target/106340] flag set from SVE svwhilelt intrinsic not reused
 in loop
Date: Mon, 18 Jul 2022 13:13:27 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106340

--- Comment #1 from Yichao Yu <yyc1992 at gmail dot com> ---
Also note that this is for code I've tweaked to match what the finally code=
 as
much as possible. For a complete implementation of this, I expect the loop
transformation done for normal loop should move the whilelt as well so that
source code like the following would generate pretty much the same code.

```
void set3(uint32_t *__restrict__ out, size_t m)
{
    auto svelen =3D svcntw();
    auto v =3D svdup_u32(1);
    for (size_t i =3D 0; i < m; i +=3D svelen) {
        auto pg =3D svwhilelt_b32(i, m);
        svst1(pg, &out[i], v);
    }
}
```

Currently, while the cmp was moved to the end of the loop body and the loop
header, the whilelt that is meant to be paired with it did not so the flag =
from
the whilelt instruction isn't directly usable as is in the code.=