[PATCH] D59816: [Support] Implement zlib independent crc32 computation

[Eugene Leviant via Phabricator via llvm-commits]

evgeny777 marked 2 inline comments as done.
evgeny777 added inline comments.


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Comment at: include/llvm/Support/CRC.h:22
+// zlib independent CRC32 calculation.
+uint32_t getCRC32(uint32_t CRC, StringRef S);
+} // end namespace llvm
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lebedev.ri wrote:
> I'm not sure if oss-fuzz builds llvm with zlib or not, but if it **does**,
> this is a *great* fuzzing target, to cross-check with the zlib output.
LLVM_ENABLE_ZLIB is ON by default, so whether LLVM is built with zlib support or not depends on HAVE_ZLIB_H.
Are you suggesting something like `llvm-crc32-fuzzer`?


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Comment at: lib/DebugInfo/Symbolize/Symbolize.cpp:167
     return false;
-  return !zlib::isAvailable() || CRCHash == zlib::crc32(MB.get()->getBuffer());
+  return CRCHash == (zlib::isAvailable()
+                         ? zlib::crc32(MB.get()->getBuffer())
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grimar wrote:
> What about always using non-zlib implementation?
zlib implementation is most likely faster, especially with -DBYFOUR. Also somebody may be using llvm::zlib::crc32 



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