[FIX] More elegant solution, probably

include/hibf/sketch/hyperloglog.hpp

@@ -54,10 +54,14 @@ class hyperloglog
      */
     void add(std::string_view const sv);
 
+    // Note: Sometimes, LTO optimizes the function body away. In particular, when value is in a register.
+    // Using const & is more or less the same as using `asm inline("" : : "m"(value));`, but it can still optimize
+    // for memory addresses and registers when inlining, whereas the asm will always create a memory address.
+
     /*!\brief Adds an unsigned 64-bit integer to the estimator.
      * \param[in] value unsigned integer to add
      */
-    void add(uint64_t const value);
+    void add(uint64_t const & value);
 
     /*!\brief Estimates cardinality value.
      * \returns Estimated cardinality value.

src/sketch/hyperloglog.cpp

@@ -59,10 +59,8 @@ void hyperloglog::add(std::string_view const sv)
     M_[index] = std::max(rank, M_[index]);
 }
 
-void hyperloglog::add(uint64_t const value)
+void hyperloglog::add(uint64_t const & value)
 {
-    // chopper hibf_statistics, gcc13 + lto: overzealous optimization results in wrong results
-    asm volatile("" : : "r,m"(value) : "memory");
     uint64_t const hash = XXH3_64bits(&value, sizeof(uint64_t));
     // the first b_ bits are used to distribute the leading zero counts along M_
     uint64_t const index = hash >> (64 - b_);