commit 0e69e2d74739a119a78d131c29b92c25787ec2f3
author Clement Courbet <courbet@google.com> Thu May 17 10:52:18 2018 +0000
committer Clement Courbet <courbet@google.com> Thu May 17 10:52:18 2018 +0000
tree c808110b4a710daf2bed231cc96e1e3af1558294
parent ceb4933dc1dc4e769ea9e1752a8cb8425de09002

reland r332579: [llvm-exegesis] Update to cover latency through another opcode.

Restructuring the code to measure latency and uops.
The end goal is to have this program spawn another process to deal with SIGILL and other malformed programs. It is not yet the case in this redesign, it is still the main program that runs the code (and may crash).
It now uses BitVector instead of Graph for performance reasons.

https://reviews.llvm.org/D46821

(with fixed ARM tests)

Authored by Guillaume Chatelet

llvm-svn: 332592

llvm/tools/llvm-exegesis/llvm-exegesis.cpp

diff --git a/llvm/tools/llvm-exegesis/llvm-exegesis.cpp b/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
index a872c75..2b77288 100644
--- a/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
+++ b/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
@@ -76,14 +76,23 @@
 
 namespace exegesis {
 
+static unsigned GetOpcodeOrDie(const llvm::MCInstrInfo &MCInstrInfo) {
+  if (OpcodeName.empty() && (OpcodeIndex == 0))
+    llvm::report_fatal_error(
+        "please provide one and only one of 'opcode-index' or 'opcode-name'");
+  if (OpcodeIndex > 0)
+    return OpcodeIndex;
+  // Resolve opcode name -> opcode.
+  for (unsigned I = 0, E = MCInstrInfo.getNumOpcodes(); I < E; ++I)
+    if (MCInstrInfo.getName(I) == OpcodeName)
+      return I;
+  llvm::report_fatal_error(llvm::Twine("unknown opcode ").concat(OpcodeName));
+}
+
 void benchmarkMain() {
   if (exegesis::pfm::pfmInitialize())
     llvm::report_fatal_error("cannot initialize libpfm");
 
-  if (OpcodeName.empty() == (OpcodeIndex == 0))
-    llvm::report_fatal_error(
-        "please provide one and only one of 'opcode-index' or 'opcode-name'");
-
   llvm::InitializeNativeTarget();
   llvm::InitializeNativeTargetAsmPrinter();
 
@@ -92,37 +101,26 @@
 
   const LLVMState State;
 
+  // FIXME: Do not require SchedModel for latency.
   if (!State.getSubtargetInfo().getSchedModel().hasExtraProcessorInfo())
     llvm::report_fatal_error("sched model is missing extra processor info!");
 
-  unsigned Opcode = OpcodeIndex;
-  if (Opcode == 0) {
-    // Resolve opcode name -> opcode.
-    for (unsigned I = 0, E = State.getInstrInfo().getNumOpcodes(); I < E; ++I) {
-      if (State.getInstrInfo().getName(I) == OpcodeName) {
-        Opcode = I;
-        break;
-      }
-    }
-    if (Opcode == 0) {
-      llvm::report_fatal_error(
-          llvm::Twine("unknown opcode ").concat(OpcodeName));
-    }
-  }
-
   std::unique_ptr<BenchmarkRunner> Runner;
   switch (BenchmarkMode) {
   case BenchmarkModeE::Latency:
-    Runner = llvm::make_unique<LatencyBenchmarkRunner>();
+    Runner = llvm::make_unique<LatencyBenchmarkRunner>(State);
     break;
   case BenchmarkModeE::Uops:
-    Runner = llvm::make_unique<UopsBenchmarkRunner>();
+    Runner = llvm::make_unique<UopsBenchmarkRunner>(State);
     break;
   case BenchmarkModeE::Analysis:
     llvm_unreachable("not a benchmark");
   }
 
-  Runner->run(State, Opcode, NumRepetitions > 0 ? NumRepetitions : 1, Filter)
+  if (NumRepetitions == 0)
+    llvm::report_fatal_error("--num-repetitions must be greater than zero");
+
+  Runner->run(GetOpcodeOrDie(State.getInstrInfo()), Filter, NumRepetitions)
       .writeYamlOrDie(BenchmarkFile);
   exegesis::pfm::pfmTerminate();
 }