[PATCH] D35221: [scudo] PRNG makeover

[Kostya Kortchinsky via Phabricator via llvm-commits]

cryptoad added inline comments.


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Comment at: lib/scudo/scudo_allocator.cpp:583
     initThreadMaybe();
-    if (CheckForCallocOverflow(NMemB, Size))
+    if (UNLIKELY(CheckForCallocOverflow(NMemB, Size)))
       return FailureHandler::OnBadRequest();
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alekseyshl wrote:
> This change is unrelated, please revert.
Ack. Slipped in from another one sorry.


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Comment at: lib/scudo/scudo_utils.h:84
+    // size of the random data left in the cache.
+    CachedBytes = next() | (1ULL << 63);
+  }
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alekseyshl wrote:
> Does this trick really help with performance?
The numbers do not differ enough to go one way or the other, but the u8 was taking up to extra 8bytes depending on architecture. It feels it should be faster, but it definitely save space.


https://reviews.llvm.org/D35221