Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Remove OPENSSL_ia32cap_P references from AES-NI assembly
The AES-NI key schedule functions have two versions, dating to OpenSSL's 23f6eec71dbd472044db7dc854599f1de14a1f48. This cites RT#3576. Unfortunately, OpenSSL purged their old RT bugs, without any archives, so this context is now lost. Some archives of openssl-dev discussion (also predating OpenSSL's archives) give most of the context: https://groups.google.com/g/mailing.openssl.dev/c/OuFXwW4NfO8/m/7d2ZXVjkxVkJ Broadly, although AES-NI has an aeskeygenassist instruction for the key schedule, apparently it's overall faster to ignore it and use aesenclast instead. But it's slower on older processors, so the assembly would check for AVX && !XOP as a proxy. (Note we always set XOP to false, even though this likely wasn't a capability check but a proxy for pre-Xen AMD chips.) It is unclear if the aeskeygenassist version is still worthwhile. However, the aesenclast version requires SSSE3. SSSE3 long predates AES-NI, but it's not clear if AES-NI implies SSSE3. In OpenSSL, the CCM AES-NI assembly seems to assume it does. For now, I've preserved the pair of them. There are now only two assembly files with OPENSSL_ia32cap_P references! Bug: 673 Change-Id: I990b1393d780db4caf074c184ce8bbd182da6e29 Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/68690 Reviewed-by: Bob Beck <bbe@google.com> Commit-Queue: David Benjamin <davidben@google.com>
- Loading branch information