[MachineOutliner] Add statistics for unsigned vector size

Useful for debugging + evaluating improvements to the outliner.

Stats are the number of illegal, legal, and invisible instructions in the
unsigned vector, and it's total length.

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp
index d7d0982..7ce655d 100644
--- a/llvm/lib/CodeGen/MachineOutliner.cpp
+++ b/llvm/lib/CodeGen/MachineOutliner.cpp
@@ -82,9 +82,17 @@ using namespace llvm;
 using namespace ore;
 using namespace outliner;
 
+// Statistics for outlined functions.
 STATISTIC(NumOutlined, "Number of candidates outlined");
 STATISTIC(FunctionsCreated, "Number of functions created");
 
+// Statistics for instruction mapping.
+STATISTIC(NumLegalInUnsignedVec, "Number of legal instrs in unsigned vector");
+STATISTIC(NumIllegalInUnsignedVec,
+          "Number of illegal instrs in unsigned vector");
+STATISTIC(NumInvisible, "Number of invisible instrs in unsigned vector");
+STATISTIC(UnsignedVecSize, "Size of unsigned vector");
+
 // Set to true if the user wants the outliner to run on linkonceodr linkage
 // functions. This is false by default because the linker can dedupe linkonceodr
 // functions. Since the outliner is confined to a single module (modulo LTO),
@@ -188,6 +196,8 @@ struct InstructionMapper {
     assert(LegalInstrNumber != DenseMapInfo<unsigned>::getTombstoneKey() &&
            "Tried to assign DenseMap tombstone or empty key to instruction.");
 
+    // Statistics.
+    ++NumLegalInUnsignedVec;
     return MINumber;
   }
 
@@ -215,6 +225,8 @@ struct InstructionMapper {
     InstrListForMBB.push_back(It);
     UnsignedVecForMBB.push_back(IllegalInstrNumber);
     IllegalInstrNumber--;
+    // Statistics.
+    ++NumIllegalInUnsignedVec;
 
     assert(LegalInstrNumber < IllegalInstrNumber &&
            "Instruction mapping overflow!");
@@ -293,6 +305,7 @@ struct InstructionMapper {
       case InstrType::Invisible:
         // Normally this is set by mapTo(Blah)Unsigned, but we just want to
         // skip this instruction. So, unset the flag here.
+        ++NumInvisible;
         AddedIllegalLastTime = false;
         break;
       }
@@ -905,6 +918,9 @@ void MachineOutliner::populateMapper(InstructionMapper &Mapper, Module &M,
       // MBB is suitable for outlining. Map it to a list of unsigneds.
       Mapper.convertToUnsignedVec(MBB, *TII);
     }
+
+    // Statistics.
+    UnsignedVecSize = Mapper.UnsignedVec.size();
   }
 }