[llvm] r366020 - [Hashing] hash_1to3_bytes - avoid trunc(v + zext(x)) NFCI.

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Sun Jul 14 08:05:05 2019
New Revision: 366020

URL: http://llvm.org/viewvc/llvm-project?rev=366020&view=rev
Log:
[Hashing] hash_1to3_bytes - avoid trunc(v + zext(x)) NFCI.

MSVC complains about the extension to uint64_t for an addition followed by truncation back to uint32_t - add an explicit uint32_t cast to avoid this.

Modified:
    llvm/trunk/include/llvm/ADT/Hashing.h

Modified: llvm/trunk/include/llvm/ADT/Hashing.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/Hashing.h?rev=366020&r1=366019&r2=366020&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/Hashing.h (original)
+++ llvm/trunk/include/llvm/ADT/Hashing.h Sun Jul 14 08:05:05 2019
@@ -191,7 +191,7 @@ inline uint64_t hash_1to3_bytes(const ch
   uint8_t b = s[len >> 1];
   uint8_t c = s[len - 1];
   uint32_t y = static_cast<uint32_t>(a) + (static_cast<uint32_t>(b) << 8);
-  uint32_t z = len + (static_cast<uint32_t>(c) << 2);
+  uint32_t z = static_cast<uint32_t>(len) + (static_cast<uint32_t>(c) << 2);
   return shift_mix(y * k2 ^ z * k3 ^ seed) * k2;
 }