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, 3 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
index 3862f19ab7a..ca1bb62389e 100644
--- a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
@@ -96,6 +96,7 @@
 #include "llvm/ProfileData/InstrProf.h"
 #include "llvm/ProfileData/InstrProfReader.h"
 #include "llvm/Support/BranchProbability.h"
+#include "llvm/Support/CRC.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/DOTGraphTraits.h"
@@ -103,7 +104,6 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/GraphWriter.h"
-#include "llvm/Support/JamCRC.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Instrumentation.h"
 #include "llvm/Transforms/Instrumentation/PGOInstrumentation.h"
@@ -609,7 +609,7 @@ public:
 // value of each BB in the CFG. The higher 32 bits record the number of edges.
 template <class Edge, class BBInfo>
 void FuncPGOInstrumentation<Edge, BBInfo>::computeCFGHash() {
-  std::vector<char> Indexes;
+  std::vector<uint8_t> Indexes;
   JamCRC JC;
   for (auto &BB : F) {
     const Instruction *TI = BB.getTerminator();
@@ -620,7 +620,7 @@ void FuncPGOInstrumentation<Edge, BBInfo>::computeCFGHash() {
         continue;
       uint32_t Index = BI->Index;
       for (int J = 0; J < 4; J++)
-        Indexes.push_back((char)(Index >> (J * 8)));
+        Indexes.push_back((uint8_t)(Index >> (J * 8)));
     }
   }
   JC.update(Indexes);