[PATCH] D49923: Support: xxHash64: Zero extend byte values loaded from the input data.

[Peter Collingbourne via Phabricator via llvm-commits]

pcc created this revision.
pcc added a reviewer: ruiu.
Herald added a subscriber: hiraditya.

This matches the reference implementation:
https://github.com/Cyan4973/xxHash/blob/3064d42e7d74b0921bdd1818395d9cb37bb8976a/xxhash.c#L707
https://github.com/Cyan4973/xxHash/blob/3064d42e7d74b0921bdd1818395d9cb37bb8976a/xxhash.c#L147

and makes the behaviour independent of whether we are compiled with
-funsigned-char.


Repository:
  rL LLVM

https://reviews.llvm.org/D49923

Files:
  llvm/lib/Support/xxhash.cpp


Index: llvm/lib/Support/xxhash.cpp
===================================================================
--- llvm/lib/Support/xxhash.cpp
+++ llvm/lib/Support/xxhash.cpp
@@ -119,7 +119,7 @@
   }
 
   while (P < BEnd) {
-    H64 ^= (*P) * PRIME64_5;
+    H64 ^= uint8_t(*P) * PRIME64_5;
     H64 = rotl64(H64, 11) * PRIME64_1;
     P++;
   }


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