Tweak changelog

Author: taiki-e

CHANGELOG.md

@@ -40,7 +40,7 @@ Note: In this file, do not use the hard wrap in the middle of a sentence for com
 - Fix compile error on `bpf{eb,el}-unknown-none` (tier 3) and `mipsel-sony-psx` (tier 3) when `critical-section` feature is disabled.
 
 - Various optimizations
-  - Optimize x86_64 128-bit outline-atomics. This improves performance by up to 15% in concurrent RMW/store. ([40c4cd4](https://github.com/taiki-e/portable-atomic/commit/40c4cd4f682f1cb153f18d4d6a88795bafaf5667))
+  - Optimize x86_64 128-bit outline-atomics. This improves performance by up to 15% in concurrent RMW/store for cases where the `cmpxchg16b` target feature is not available at compile-time. ([40c4cd4](https://github.com/taiki-e/portable-atomic/commit/40c4cd4f682f1cb153f18d4d6a88795bafaf5667))
   - Optimize x86_64 128-bit load that uses cmpxchg16b. ([40c4cd4](https://github.com/taiki-e/portable-atomic/commit/40c4cd4f682f1cb153f18d4d6a88795bafaf5667))
   - Optimize aarch64 128-bit load that uses FEAT_LSE. ([40c4cd4](https://github.com/taiki-e/portable-atomic/commit/40c4cd4f682f1cb153f18d4d6a88795bafaf5667))
   - Optimize pre-ARMv6 Linux/Android atomics. ([efacc89](https://github.com/taiki-e/portable-atomic/commit/efacc89c210d7a34ef5e879821112189da5d1901))