SHA512 extension test fails with clang

The SHA512 extension test fails with:

crypto/sha: 
  FAIL src/test/test_crypto.c:432: assert(d_out1 OP_EQ d_out2): DE642E63D5B73FC396C12BE38B2BD5D884257C32 vs 17807C728EE3BA35E7CF7AF823116D26E41E5D4D
  [sha FAILED]

with x86_64 and i386 clang on OS X:

Apple LLVM version 7.0.0 (clang-700.1.76)

and x86_64 clang on Linux:

Ubuntu clang version 3.4-1ubuntu3 (tags/RELEASE_34/final) (based on LLVM 3.4)

But gcc works fine on Linux:

gcc version 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04)