[llvm-branch-commits] compiler-rt: Introduce runtime functions for emulated PAC. (PR #133530)

[Peter Collingbourne via llvm-branch-commits]

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@@ -0,0 +1,7343 @@
+/*
+ * xxHash - Extremely Fast Hash algorithm
+ * Header File
+ * Copyright (C) 2012-2023 Yann Collet
+ *
+ * BSD 2-Clause License (https://www.opensource.org/licenses/bsd-license.php)
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pcc wrote:

Understood, I've uploaded a new change that replaces the hash with SipHash.

Unfortunately SipHash is subtantially slower than xxhash and led to a ~3.5x slowdown (vs native PAC instructions) on the benchmark cited in my original RFC (and BLAKE3 isn't header only which would make it substantially harder to integrate here). Hopefully the performance hit doesn't turn out to be a problem here.

https://github.com/llvm/llvm-project/pull/133530