[llvm] [SYCL][LLVM] Adding property set I/O library for SYCL (PR #110771)

[Matt Arsenault via llvm-commits]

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@@ -90,3 +90,180 @@ llvm::Error llvm::decodeBase64(llvm::StringRef Input,
   }
   return Error::success();
 }
+
+using namespace llvm;
+
+namespace {
+
+using byte = std::byte;
+
+::llvm::Error makeError(const Twine &Msg) {
+  return createStringError(std::error_code{}, Msg);
+}
+
+class Base64Impl {
+private:
+  static constexpr char EncodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                                          "abcdefghijklmnopqrstuvwxyz"
+                                          "0123456789+/";
+
+  static_assert(sizeof(EncodingTable) == 65, "");
+
+  // Compose an index into the encoder table from two bytes and the number of
+  // significant bits in the lower byte until the byte boundary.
+  static inline int composeInd(byte ByteLo, byte ByteHi, int BitsLo) {
+    int Res = (int)((ByteHi << BitsLo) | (ByteLo >> (8 - BitsLo))) & 0x3F;
+    return Res;
+  }
+
+  // Decode a single character.
+  static inline int decode(char Ch) {
+    if (Ch >= 'A' && Ch <= 'Z') // 0..25
+      return Ch - 'A';
+    else if (Ch >= 'a' && Ch <= 'z') // 26..51
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arsenm wrote:

No else after return 

https://github.com/llvm/llvm-project/pull/110771