Unify the two CRC implementations

David added the JamCRC implementation in r246590. More recently, Eugene
added a CRC-32 implementation in r357901, which falls back to zlib's
crc32 function if present.

These checksums are essentially the same, so having multiple
implementations seems unnecessary. This replaces the CRC-32
implementation with the simpler one from JamCRC, and implements the
JamCRC interface in terms of CRC-32 since this means it can use zlib's
implementation when available, saving a few bytes and potentially making
it faster.

JamCRC took an ArrayRef<char> argument, and CRC-32 took a StringRef.
This patch changes it to ArrayRef<uint8_t> which I think is the best
choice, and simplifies a few of the callers nicely.

Differential revision: https://reviews.llvm.org/D68570

llvm-svn: 374148

1 files changed, 2 insertions, 3 deletions

diff --git a/llvm/lib/DebugInfo/PDB/Native/Hash.cpp b/llvm/lib/DebugInfo/PDB/Native/Hash.cpp
index b5c139ecbec..7fb6b4bd5d3 100644
--- a/llvm/lib/DebugInfo/PDB/Native/Hash.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/Hash.cpp
@@ -8,8 +8,8 @@
 
 #include "llvm/DebugInfo/PDB/Native/Hash.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/Support/CRC.h"
 #include "llvm/Support/Endian.h"
-#include "llvm/Support/JamCRC.h"
 #include <cstdint>
 
 using namespace llvm;
@@ -79,7 +79,6 @@ uint32_t pdb::hashStringV2(StringRef Str) {
 // Corresponds to `SigForPbCb` in langapi/shared/crc32.h.
 uint32_t pdb::hashBufferV8(ArrayRef<uint8_t> Buf) {
   JamCRC JC(/*Init=*/0U);
-  JC.update(makeArrayRef<char>(reinterpret_cast<const char *>(Buf.data()),
-                               Buf.size()));
+  JC.update(Buf);
   return JC.getCRC();
 }