Rollup merge of #143477 - folkertdev:use-is-multiple-of, r=joshtriplett

use `is_multiple_of` and `div_ceil`

In tricky logic, these functions are much more informative than the manual implementations. They also catch subtle bugs:

- the manual `is_multiple_of` often does not handle division by zero
- manual `div_ceil` often does not consider overflow

The transformation is free for `is_multiple_of` if the divisor is compile-time known to be non-zero. For `div_ceil` there is a small cost to considering overflow. Here is some assembly https://godbolt.org/z/5zP8KaE1d.

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/rustc_query_system/src/query/plumbing.rs b/compiler/rustc_query_system/src/query/plumbing.rs
index 3c1fc731784..06e59eb4ccc 100644
--- a/compiler/rustc_query_system/src/query/plumbing.rs
+++ b/compiler/rustc_query_system/src/query/plumbing.rs
@@ -597,7 +597,7 @@ where
         // from disk. Re-hashing results is fairly expensive, so we can't
         // currently afford to verify every hash. This subset should still
         // give us some coverage of potential bugs though.
-        let try_verify = prev_fingerprint.split().1.as_u64() % 32 == 0;
+        let try_verify = prev_fingerprint.split().1.as_u64().is_multiple_of(32);
         if std::intrinsics::unlikely(
             try_verify || qcx.dep_context().sess().opts.unstable_opts.incremental_verify_ich,
         ) {