Re: Unaligned access trade-offs for SFrame FRE layout
Jan Beulich <[email protected]> Sun, 14 Sep 2025 16:14:33 +0200
| Newsgroups | org.kernel.vger.linux-toolchains |
|---|---|
| Message-ID | <[email protected]> |
On 12.09.2025 19:34, Indu Bhagat via Binutils wrote: > TL;DR: Thinking and experimenting a bit on the possible approaches for > avoiding unaligned accesses in the SFrame FRE layout (in SFrame V3), I > am not convinced that avoiding unaligned accesses for performance is > worth it. IMO, forsaking compactness for avoiding unaligned accesses is > not a good trade off for SFrame. > > Problem Statement > On architectures such as x86_64, AArch64, and s390x, unaligned memory > accesses are handled transparently by the hardware but incur a > performance penalty. As you say in a reply, may incur. However, shouldn't we also consider possible ports of SFrame to architectures which don't handle this as transparently? Off the top of my head I don't, for example, recall whether RISC-V requires unaligned accesses to be handled transparently by the hardware. Jan