[llvm-exegesis][NFC] Return many CodeTemplates instead of one.

Summary: This is part one of the change where I simply changed the signature of the functions. More work need to be done to actually produce more than one CodeTemplate per instruction.

Reviewers: courbet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D53209

llvm-svn: 344493

1 files changed, 39 insertions, 28 deletions

diff --git a/llvm/tools/llvm-exegesis/lib/SnippetGenerator.cpp b/llvm/tools/llvm-exegesis/lib/SnippetGenerator.cpp
index f7a76d88ccf..9b577fd65a9 100644
--- a/llvm/tools/llvm-exegesis/lib/SnippetGenerator.cpp
+++ b/llvm/tools/llvm-exegesis/lib/SnippetGenerator.cpp
@@ -22,6 +22,12 @@
 
 namespace exegesis {
 
+std::vector<CodeTemplate> getSingleton(CodeTemplate &CT) {
+  std::vector<CodeTemplate> Result;
+  Result.push_back(std::move(CT));
+  return Result;
+}
+
 SnippetGeneratorFailure::SnippetGeneratorFailure(const llvm::Twine &S)
     : llvm::StringError(S, llvm::inconvertibleErrorCode()) {}
 
@@ -31,26 +37,28 @@ SnippetGenerator::~SnippetGenerator() = default;
 
 llvm::Expected<std::vector<BenchmarkCode>>
 SnippetGenerator::generateConfigurations(const Instruction &Instr) const {
-  if (auto E = generateCodeTemplate(Instr)) {
-    CodeTemplate &CT = E.get();
+  if (auto E = generateCodeTemplates(Instr)) {
     const auto &RATC = State.getRATC();
-    const llvm::BitVector &ForbiddenRegs =
-        CT.ScratchSpacePointerInReg
-            ? RATC.getRegister(CT.ScratchSpacePointerInReg).aliasedBits()
-            : RATC.emptyRegisters();
     std::vector<BenchmarkCode> Output;
-    // TODO: Generate as many BenchmarkCode as needed.
-    {
-      BenchmarkCode BC;
-      BC.Info = CT.Info;
-      for (InstructionTemplate &IT : CT.Instructions) {
-        randomizeUnsetVariables(ForbiddenRegs, IT);
-        BC.Instructions.push_back(IT.build());
+    for (CodeTemplate &CT : E.get()) {
+      const llvm::BitVector &ForbiddenRegs =
+          CT.ScratchSpacePointerInReg
+              ? RATC.getRegister(CT.ScratchSpacePointerInReg).aliasedBits()
+              : RATC.emptyRegisters();
+      // TODO: Generate as many BenchmarkCode as needed.
+      {
+        BenchmarkCode BC;
+        BC.Info = CT.Info;
+        for (InstructionTemplate &IT : CT.Instructions) {
+          randomizeUnsetVariables(ForbiddenRegs, IT);
+          BC.Instructions.push_back(IT.build());
+        }
+        if (CT.ScratchSpacePointerInReg)
+          BC.LiveIns.push_back(CT.ScratchSpacePointerInReg);
+        BC.RegisterInitialValues =
+            computeRegisterInitialValues(CT.Instructions);
+        Output.push_back(std::move(BC));
       }
-      if (CT.ScratchSpacePointerInReg)
-        BC.LiveIns.push_back(CT.ScratchSpacePointerInReg);
-      BC.RegisterInitialValues = computeRegisterInitialValues(CT.Instructions);
-      Output.push_back(std::move(BC));
     }
     return Output;
   } else
@@ -99,13 +107,14 @@ std::vector<RegisterValue> SnippetGenerator::computeRegisterInitialValues(
   return RIV;
 }
 
-llvm::Expected<CodeTemplate> SnippetGenerator::generateSelfAliasingCodeTemplate(
-    const Instruction &Instr) const {
+llvm::Expected<std::vector<CodeTemplate>>
+generateSelfAliasingCodeTemplates(const Instruction &Instr) {
   const AliasingConfigurations SelfAliasing(Instr, Instr);
-  if (SelfAliasing.empty()) {
+  if (SelfAliasing.empty())
     return llvm::make_error<SnippetGeneratorFailure>("empty self aliasing");
-  }
-  CodeTemplate CT;
+  std::vector<CodeTemplate> Result;
+  Result.emplace_back();
+  CodeTemplate &CT = Result.back();
   InstructionTemplate IT(Instr);
   if (SelfAliasing.hasImplicitAliasing()) {
     CT.Info = "implicit Self cycles, picking random values.";
@@ -116,16 +125,18 @@ llvm::Expected<CodeTemplate> SnippetGenerator::generateSelfAliasingCodeTemplate(
     setRandomAliasing(SelfAliasing, IT, IT);
   }
   CT.Instructions.push_back(std::move(IT));
-  return std::move(CT);
+  return Result;
 }
 
-llvm::Expected<CodeTemplate>
-SnippetGenerator::generateUnconstrainedCodeTemplate(const Instruction &Instr,
-                                                    llvm::StringRef Msg) const {
-  CodeTemplate CT;
+llvm::Expected<std::vector<CodeTemplate>>
+generateUnconstrainedCodeTemplates(const Instruction &Instr,
+                                   llvm::StringRef Msg) {
+  std::vector<CodeTemplate> Result;
+  Result.emplace_back();
+  CodeTemplate &CT = Result.back();
   CT.Info = llvm::formatv("{0}, repeating an unconstrained assignment", Msg);
   CT.Instructions.emplace_back(Instr);
-  return std::move(CT);
+  return Result;
 }
 
 std::mt19937 &randomGenerator() {