> Use of the "h" register slices (bits 8..15) by compilers is thankfully pretty rare -- otherwise this would have been noticed much sooner!
It's actually pretty easy to get compilers to use those, you mainly need a bunch of narrow accesses to neighboring memory. The oodle post contains a godbolt link to pretty ordinary c code triggering this.
I'd guess that you also need some other conditions (multiple in flight stores, high boost speeds) to trigger this.
It's actually pretty easy to get compilers to use those, you mainly need a bunch of narrow accesses to neighboring memory. The oodle post contains a godbolt link to pretty ordinary c code triggering this.
I'd guess that you also need some other conditions (multiple in flight stores, high boost speeds) to trigger this.