diff --git a/tools/llvm-exegesis/lib/SnippetGenerator.h b/tools/llvm-exegesis/lib/SnippetGenerator.h
index ebea886d3c7..d1e20b9b36a 100644
--- a/tools/llvm-exegesis/lib/SnippetGenerator.h
+++ b/tools/llvm-exegesis/lib/SnippetGenerator.h
@@ -156,9 +156,9 @@ class CombinationGenerator {
   };
 
   const ArrayRef<choices_storage_type> VariablesChoices;
-  const function_ref<bool(ArrayRef<choice_type>)> &Callback;
 
-  void performGeneration() const {
+  void performGeneration(
+      const function_ref<bool(ArrayRef<choice_type>)> Callback) const {
     SmallVector<WrappingIterator<choice_type>, variable_smallsize>
         VariablesState;
 
@@ -200,9 +200,8 @@ class CombinationGenerator {
   };
 
 public:
-  CombinationGenerator(ArrayRef<choices_storage_type> VariablesChoices_,
-                       const function_ref<bool(ArrayRef<choice_type>)> &Cb_)
-      : VariablesChoices(VariablesChoices_), Callback(Cb_) {
+  CombinationGenerator(ArrayRef<choices_storage_type> VariablesChoices_)
+      : VariablesChoices(VariablesChoices_) {
 #ifndef NDEBUG
     assert(!VariablesChoices.empty() && "There should be some variables.");
     llvm::for_each(VariablesChoices, [](ArrayRef<choice_type> VariableChoices) {
@@ -225,7 +224,9 @@ public:
 
   // Actually perform exhaustive combination generation.
   // Each result will be passed into the callback.
-  void generate() { performGeneration(); }
+  void generate(const function_ref<bool(ArrayRef<choice_type>)> Callback) {
+    performGeneration(Callback);
+  }
 };
 
 } // namespace exegesis
diff --git a/tools/llvm-exegesis/lib/X86/Target.cpp b/tools/llvm-exegesis/lib/X86/Target.cpp
index 3dcac2553a0..232af30b4ae 100644
--- a/tools/llvm-exegesis/lib/X86/Target.cpp
+++ b/tools/llvm-exegesis/lib/X86/Target.cpp
@@ -784,18 +784,18 @@ std::vector<InstructionTemplate> ExegesisX86Target::generateInstructionVariants(
   std::vector<InstructionTemplate> Variants;
   size_t NumVariants;
   CombinationGenerator<MCOperand, decltype(VariableChoices)::value_type, 4> G(
-      VariableChoices, [&](ArrayRef<MCOperand> State) -> bool {
-        Variants.emplace_back(&Instr);
-        Variants.back().setVariableValues(State);
-        // Did we run out of space for variants?
-        return Variants.size() >= NumVariants;
-      });
+      VariableChoices);
 
   // How many operand combinations can we produce, within the limit?
   NumVariants = std::min(G.numCombinations(), (size_t)MaxConfigsPerOpcode);
   // And actually produce all the wanted operand combinations.
   Variants.reserve(NumVariants);
-  G.generate();
+  G.generate([&](ArrayRef<MCOperand> State) -> bool {
+    Variants.emplace_back(&Instr);
+    Variants.back().setVariableValues(State);
+    // Did we run out of space for variants?
+    return Variants.size() >= NumVariants;
+  });
 
   assert(Variants.size() == NumVariants &&
          Variants.size() <= MaxConfigsPerOpcode &&
diff --git a/unittests/tools/llvm-exegesis/SnippetGeneratorTest.cpp b/unittests/tools/llvm-exegesis/SnippetGeneratorTest.cpp
index 9feff27f40d..760caa8ce32 100644
--- a/unittests/tools/llvm-exegesis/SnippetGeneratorTest.cpp
+++ b/unittests/tools/llvm-exegesis/SnippetGeneratorTest.cpp
@@ -20,13 +20,12 @@ TEST(CombinationGenerator, Square) {
   const std::vector<std::vector<int>> Choices{{0, 1}, {2, 3}};
 
   std::vector<std::vector<int>> Variants;
-  CombinationGenerator<int, std::vector<int>, 4> G(
-      Choices, [&](ArrayRef<int> State) -> bool {
-        Variants.emplace_back(State);
-        return false; // keep going
-      });
+  CombinationGenerator<int, std::vector<int>, 4> G(Choices);
   const size_t NumVariants = G.numCombinations();
-  G.generate();
+  G.generate([&](ArrayRef<int> State) -> bool {
+    Variants.emplace_back(State);
+    return false; // keep going
+  });
 
   const std::vector<std::vector<int>> ExpectedVariants{
       {0, 2},
@@ -42,13 +41,12 @@ TEST(CombinationGenerator, MiddleColumn) {
   const std::vector<std::vector<int>> Choices{{0}, {1, 2}, {3}};
 
   std::vector<std::vector<int>> Variants;
-  CombinationGenerator<int, std::vector<int>, 4> G(
-      Choices, [&](ArrayRef<int> State) -> bool {
-        Variants.emplace_back(State);
-        return false; // keep going
-      });
+  CombinationGenerator<int, std::vector<int>, 4> G(Choices);
   const size_t NumVariants = G.numCombinations();
-  G.generate();
+  G.generate([&](ArrayRef<int> State) -> bool {
+    Variants.emplace_back(State);
+    return false; // keep going
+  });
 
   const std::vector<std::vector<int>> ExpectedVariants{
       {0, 1, 3},
@@ -62,13 +60,12 @@ TEST(CombinationGenerator, SideColumns) {
   const std::vector<std::vector<int>> Choices{{0, 1}, {2}, {3, 4}};
 
   std::vector<std::vector<int>> Variants;
-  CombinationGenerator<int, std::vector<int>, 4> G(
-      Choices, [&](ArrayRef<int> State) -> bool {
-        Variants.emplace_back(State);
-        return false; // keep going
-      });
+  CombinationGenerator<int, std::vector<int>, 4> G(Choices);
   const size_t NumVariants = G.numCombinations();
-  G.generate();
+  G.generate([&](ArrayRef<int> State) -> bool {
+    Variants.emplace_back(State);
+    return false; // keep going
+  });
 
   const std::vector<std::vector<int>> ExpectedVariants{
       {0, 2, 3},
@@ -84,13 +81,12 @@ TEST(CombinationGenerator, LeftColumn) {
   const std::vector<std::vector<int>> Choices{{0, 1}, {2}};
 
   std::vector<std::vector<int>> Variants;
-  CombinationGenerator<int, std::vector<int>, 4> G(
-      Choices, [&](ArrayRef<int> State) -> bool {
-        Variants.emplace_back(State);
-        return false; // keep going
-      });
+  CombinationGenerator<int, std::vector<int>, 4> G(Choices);
   const size_t NumVariants = G.numCombinations();
-  G.generate();
+  G.generate([&](ArrayRef<int> State) -> bool {
+    Variants.emplace_back(State);
+    return false; // keep going
+  });
 
   const std::vector<std::vector<int>> ExpectedVariants{
       {0, 2},
@@ -104,13 +100,12 @@ TEST(CombinationGenerator, RightColumn) {
   const std::vector<std::vector<int>> Choices{{0}, {1, 2}};
 
   std::vector<std::vector<int>> Variants;
-  CombinationGenerator<int, std::vector<int>, 4> G(
-      Choices, [&](ArrayRef<int> State) -> bool {
-        Variants.emplace_back(State);
-        return false; // keep going
-      });
+  CombinationGenerator<int, std::vector<int>, 4> G(Choices);
   const size_t NumVariants = G.numCombinations();
-  G.generate();
+  G.generate([&](ArrayRef<int> State) -> bool {
+    Variants.emplace_back(State);
+    return false; // keep going
+  });
 
   const std::vector<std::vector<int>> ExpectedVariants{
       {0, 1},
@@ -124,13 +119,12 @@ TEST(CombinationGenerator, Column) {
   const std::vector<std::vector<int>> Choices{{0, 1}};
 
   std::vector<std::vector<int>> Variants;
-  CombinationGenerator<int, std::vector<int>, 4> G(
-      Choices, [&](ArrayRef<int> State) -> bool {
-        Variants.emplace_back(State);
-        return false; // keep going
-      });
+  CombinationGenerator<int, std::vector<int>, 4> G(Choices);
   const size_t NumVariants = G.numCombinations();
-  G.generate();
+  G.generate([&](ArrayRef<int> State) -> bool {
+    Variants.emplace_back(State);
+    return false; // keep going
+  });
 
   const std::vector<std::vector<int>> ExpectedVariants{
       {0},
@@ -144,13 +138,12 @@ TEST(CombinationGenerator, Row) {
   const std::vector<std::vector<int>> Choices{{0}, {1}};
 
   std::vector<std::vector<int>> Variants;
-  CombinationGenerator<int, std::vector<int>, 4> G(
-      Choices, [&](ArrayRef<int> State) -> bool {
-        Variants.emplace_back(State);
-        return false; // keep going
-      });
+  CombinationGenerator<int, std::vector<int>, 4> G(Choices);
   const size_t NumVariants = G.numCombinations();
-  G.generate();
+  G.generate([&](ArrayRef<int> State) -> bool {
+    Variants.emplace_back(State);
+    return false; // keep going
+  });
 
   const std::vector<std::vector<int>> ExpectedVariants{
       {0, 1},
@@ -163,13 +156,12 @@ TEST(CombinationGenerator, Singleton) {
   const std::vector<std::vector<int>> Choices{{0}};
 
   std::vector<std::vector<int>> Variants;
-  CombinationGenerator<int, std::vector<int>, 4> G(
-      Choices, [&](ArrayRef<int> State) -> bool {
-        Variants.emplace_back(State);
-        return false; // keep going
-      });
+  CombinationGenerator<int, std::vector<int>, 4> G(Choices);
   const size_t NumVariants = G.numCombinations();
-  G.generate();
+  G.generate([&](ArrayRef<int> State) -> bool {
+    Variants.emplace_back(State);
+    return false; // keep going
+  });
 
   const std::vector<std::vector<int>> ExpectedVariants{
       {0},