1 files changed, 59 insertions, 1 deletions

diff --git a/llvm/tools/llvm-exegesis/lib/CodeTemplate.h b/llvm/tools/llvm-exegesis/lib/CodeTemplate.h
index e5006eb74c9..734992f0afa 100644
--- a/llvm/tools/llvm-exegesis/lib/CodeTemplate.h
+++ b/llvm/tools/llvm-exegesis/lib/CodeTemplate.h
@@ -17,6 +17,7 @@
 #define LLVM_TOOLS_LLVM_EXEGESIS_CODETEMPLATE_H
 
 #include "MCInstrDescView.h"
+#include "llvm/ADT/BitmaskEnum.h"
 
 namespace exegesis {
 
@@ -45,9 +46,65 @@ struct InstructionTemplate {
   llvm::SmallVector<llvm::MCOperand, 4> VariableValues;
 };
 
+enum class ExecutionMode : uint8_t {
+  UNKNOWN = 0U,
+  // The instruction is always serial because implicit Use and Def alias.
+  // e.g. AAA (alias via EFLAGS)
+  ALWAYS_SERIAL_IMPLICIT_REGS_ALIAS = 1u << 0,
+
+  // The instruction is always serial because one Def is tied to a Use.
+  // e.g. AND32ri (alias via tied GR32)
+  ALWAYS_SERIAL_TIED_REGS_ALIAS = 1u << 1,
+
+  // The execution can be made serial by inserting a second instruction that
+  // clobbers/reads memory.
+  // e.g. MOV8rm
+  SERIAL_VIA_MEMORY_INSTR = 1u << 2,
+
+  // The execution can be made serial by picking one Def that aliases with one
+  // Use.
+  // e.g. VXORPSrr XMM1, XMM1, XMM2
+  SERIAL_VIA_EXPLICIT_REGS = 1u << 3,
+
+  // The execution can be made serial by inserting a second instruction that
+  // uses one of the Defs and defs one of the Uses.
+  // e.g.
+  // 1st instruction: MMX_PMOVMSKBrr ECX, MM7
+  // 2nd instruction: MMX_MOVD64rr MM7, ECX
+  //  or instruction: MMX_MOVD64to64rr MM7, ECX
+  //  or instruction: MMX_PINSRWrr MM7, MM7, ECX, 1
+  SERIAL_VIA_NON_MEMORY_INSTR = 1u << 4,
+
+  // The execution is always parallel because the instruction is missing Use or
+  // Def operands.
+  ALWAYS_PARALLEL_MISSING_USE_OR_DEF = 1u << 5,
+
+  // The execution can be made parallel by repeating the same instruction but
+  // making sure that Defs of one instruction do not alias with Uses of the
+  // second one.
+  PARALLEL_VIA_EXPLICIT_REGS = 1u << 6,
+
+  LLVM_MARK_AS_BITMASK_ENUM(/*Largest*/ PARALLEL_VIA_EXPLICIT_REGS)
+};
+
+// Returns whether Execution is one of the values defined in the enum above.
+bool isEnumValue(ExecutionMode Execution);
+
+// Returns a human readable string for the enum.
+llvm::StringRef getName(ExecutionMode Execution);
+
+// Returns a sequence of increasing powers of two corresponding to all the
+// Execution flags.
+llvm::ArrayRef<ExecutionMode> getAllExecutionBits();
+
+// Decomposes Execution into individual set bits.
+llvm::SmallVector<ExecutionMode, 4> getExecutionModeBits(ExecutionMode);
+
+LLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE();
+
 // A CodeTemplate is a set of InstructionTemplates that may not be fully
 // specified (i.e. some variables are not yet set). This allows the
-// BenchmarkRunner to instantiate it many times with specific values to study
+// SnippetGenerator to instantiate it many times with specific values to study
 // their impact on instruction's performance.
 struct CodeTemplate {
   CodeTemplate() = default;
@@ -57,6 +114,7 @@ struct CodeTemplate {
   CodeTemplate(const CodeTemplate &) = delete;
   CodeTemplate &operator=(const CodeTemplate &) = delete;
 
+  ExecutionMode Execution = ExecutionMode::UNKNOWN;
   // Some information about how this template has been created.
   std::string Info;
   // The list of the instructions for this template.