Faster/safer sampling

unitaryfund · Oct 5, 2024 · c959241 · c959241
1 parent 4e42ae5
commit c959241
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Showing 3 changed files with 48 additions and 7 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required (VERSION 3.9)
-project (Qrack VERSION 9.9.62 DESCRIPTION "High Performance Quantum Bit Simulation" LANGUAGES CXX)
+project (Qrack VERSION 9.9.65 DESCRIPTION "High Performance Quantum Bit Simulation" LANGUAGES CXX)
 
 # Installation commands
 include (GNUInstallDirs)

diff --git a/debian/changelog b/debian/changelog
@@ -1,3 +1,27 @@
+libqrack (9.9.65) bionic; urgency=medium
+
+  * Debug QBDD high rounding (Bionic 4/4)
+
+ -- Daniel Strano <dan@unitary.fund>  Fri, 04 Oct 2024 07:14:05 -0400
+
+libqrack (9.9.64) focal; urgency=medium
+
+  * Debug QBDD high rounding (Focal 3/4)
+
+ -- Daniel Strano <dan@unitary.fund>  Fri, 04 Oct 2024 07:12:25 -0400
+
+libqrack (9.9.63) jammy; urgency=medium
+
+  * Debug QBDD high rounding (Jammy 2/4)
+
+ -- Daniel Strano <dan@unitary.fund>  Fri, 04 Oct 2024 07:10:54 -0400
+
+libqrack (9.9.62) noble; urgency=medium
+
+  * Debug QBDD high rounding (Noble 1/4)
+
+ -- Daniel Strano <dan@unitary.fund>  Fri, 04 Oct 2024 06:56:49 -0400
+
 libqrack (9.9.61) bionic; urgency=medium
 
   * Debug QBDD sampling (Bionic 4/4)

diff --git a/src/qengine/qengine.cpp b/src/qengine/qengine.cpp
@@ -571,11 +571,22 @@ std::map<bitCapInt, int> QEngine::MultiShotMeasureMask(const std::vector<bitCapI
     std::discrete_distribution<bitCapIntOcl> dist(maskProbsVec.begin(), maskProbsVec.end());
 
     std::random_device rd;
-    std::mt19937 gen(rd());
+    std::vector<std::mt19937> genVec;
+    const unsigned numThreads = GetConcurrencyLevel();
+    genVec.reserve(numThreads);
+    for (unsigned i = 0U; i < numThreads; ++i) {
+        genVec.emplace_back(rd());
+    }
+    std::vector<std::map<bitCapInt, int>> resultsVec(numThreads);
+
+    par_for(0, shots, [&](const bitCapIntOcl& shot, const unsigned& cpu) { ++(resultsVec[cpu][dist(genVec[cpu])]); });
 
-    std::map<bitCapInt, int> results;
-    for (unsigned int shot = 0U; shot < shots; ++shot) {
-        ++(results[dist(gen)]);
+    std::map<bitCapInt, int> results(resultsVec[0U]);
+    for (size_t i = 1U; i < resultsVec.size(); ++i) {
+        const std::map<bitCapInt, int>& toAdd = resultsVec[i];
+        for (auto const& kv : toAdd) {
+            results[kv.first] += kv.second;
+        }
     }
 
     return results;
@@ -600,9 +611,15 @@ void QEngine::MultiShotMeasureMask(
     std::discrete_distribution<bitCapIntOcl> dist(maskProbsVec.begin(), maskProbsVec.end());
 
     std::random_device rd;
-    std::mt19937 gen(rd());
+    std::vector<std::mt19937> genVec;
+    const unsigned numThreads = GetConcurrencyLevel();
+    genVec.reserve(numThreads);
+    for (unsigned i = 0U; i < numThreads; ++i) {
+        genVec.emplace_back(rd());
+    }
 
-    par_for(0, shots, [&](const bitCapIntOcl& shot, const unsigned& cpu) { shotsArray[shot] = (unsigned)dist(gen); });
+    par_for(0, shots,
+        [&](const bitCapIntOcl& shot, const unsigned& cpu) { shotsArray[shot] = (unsigned)dist(genVec[cpu]); });
 }
 
 } // namespace Qrack