[llvm] [llvm-profdata] Emit error when counter value is greater than 2^56. (PR #69513)

[via llvm-commits]

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@@ -38,6 +38,9 @@
 
 using namespace llvm;
 
+// Maxium counter value 2^56.
+static uint64_t MaxCounterValue = 0xffffffffffffff;
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zmodem wrote:

Something like `(1ULL << 56)` would be easier to read than trying to count the number of `f`'s (which are technically 2^56-1 ;)

https://github.com/llvm/llvm-project/pull/69513