[CodeGen] Pass SDAG an ORE, and replace FastISel stats with remarks.

In the long-term, we want to replace statistics with something
finer-grained that lets us gather per-function data.
Remarks are that replacement.

Create an ORE instance in SelectionDAGISel, and pass it to
SelectionDAG.

SelectionDAG was used so that we can emit remarks from all
SelectionDAG-related code, including TargetLowering and DAGCombiner.
This isn't used in the current patch but Adam tells me he's interested
for the fp-contract combines.

Use the ORE instance to emit FastISel failures as remarks (instead of
the mix of dbgs() dumps and statistics that we currently have).

Eventually, we want to have an API that tells us whether remarks are
enabled (http://llvm.org/PR32352) so that we don't emit expensive
remarks (in this case, dumping IR) when it's not needed.  For now, use
'isEnabled' as a crude replacement.

This does mean that the replacement for '-fast-isel-verbose' is now
'-pass-remarks-missed=isel'.  Additionally, clang users also need to
enable remark diagnostics, using '-Rpass-missed=isel'.

This also removes '-fast-isel-verbose2': there are no static statistics
that we want to only enable in asserts builds, so we can always use
the remarks regardless of the build type.

Differential Revision: https://reviews.llvm.org/D31405

llvm-svn: 299093

2 files changed, 61 insertions, 242 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 68257e96982..68216d0dd29 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -871,11 +871,13 @@ SelectionDAG::SelectionDAG(const TargetMachine &tm, CodeGenOpt::Level OL)
   DbgInfo = new SDDbgInfo();
 }
 
-void SelectionDAG::init(MachineFunction &mf) {
-  MF = &mf;
+void SelectionDAG::init(MachineFunction &NewMF,
+                        OptimizationRemarkEmitter &NewORE) {
+  MF = &NewMF;
+  ORE = &NewORE;
   TLI = getSubtarget().getTargetLowering();
   TSI = getSubtarget().getSelectionDAGInfo();
-  Context = &mf.getFunction()->getContext();
+  Context = &MF->getFunction()->getContext();
 }
 
 SelectionDAG::~SelectionDAG() {
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 123938646a3..e21204dbb96 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -26,6 +26,7 @@
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/BranchProbabilityInfo.h"
 #include "llvm/Analysis/CFG.h"
+#include "llvm/Analysis/OptimizationDiagnosticInfo.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/CodeGen/FastISel.h"
 #include "llvm/CodeGen/FunctionLoweringInfo.h"
@@ -104,104 +105,6 @@ STATISTIC(NumEntryBlocks, "Number of entry blocks encountered");
 STATISTIC(NumFastIselFailLowerArguments,
           "Number of entry blocks where fast isel failed to lower arguments");
 
-#ifndef NDEBUG
-static cl::opt<bool>
-EnableFastISelVerbose2("fast-isel-verbose2", cl::Hidden,
-          cl::desc("Enable extra verbose messages in the \"fast\" "
-                   "instruction selector"));
-
-  // Terminators
-STATISTIC(NumFastIselFailRet,"Fast isel fails on Ret");
-STATISTIC(NumFastIselFailBr,"Fast isel fails on Br");
-STATISTIC(NumFastIselFailSwitch,"Fast isel fails on Switch");
-STATISTIC(NumFastIselFailIndirectBr,"Fast isel fails on IndirectBr");
-STATISTIC(NumFastIselFailInvoke,"Fast isel fails on Invoke");
-STATISTIC(NumFastIselFailResume,"Fast isel fails on Resume");
-STATISTIC(NumFastIselFailUnreachable,"Fast isel fails on Unreachable");
-
-  // Standard binary operators...
-STATISTIC(NumFastIselFailAdd,"Fast isel fails on Add");
-STATISTIC(NumFastIselFailFAdd,"Fast isel fails on FAdd");
-STATISTIC(NumFastIselFailSub,"Fast isel fails on Sub");
-STATISTIC(NumFastIselFailFSub,"Fast isel fails on FSub");
-STATISTIC(NumFastIselFailMul,"Fast isel fails on Mul");
-STATISTIC(NumFastIselFailFMul,"Fast isel fails on FMul");
-STATISTIC(NumFastIselFailUDiv,"Fast isel fails on UDiv");
-STATISTIC(NumFastIselFailSDiv,"Fast isel fails on SDiv");
-STATISTIC(NumFastIselFailFDiv,"Fast isel fails on FDiv");
-STATISTIC(NumFastIselFailURem,"Fast isel fails on URem");
-STATISTIC(NumFastIselFailSRem,"Fast isel fails on SRem");
-STATISTIC(NumFastIselFailFRem,"Fast isel fails on FRem");
-
-  // Logical operators...
-STATISTIC(NumFastIselFailAnd,"Fast isel fails on And");
-STATISTIC(NumFastIselFailOr,"Fast isel fails on Or");
-STATISTIC(NumFastIselFailXor,"Fast isel fails on Xor");
-
-  // Memory instructions...
-STATISTIC(NumFastIselFailAlloca,"Fast isel fails on Alloca");
-STATISTIC(NumFastIselFailLoad,"Fast isel fails on Load");
-STATISTIC(NumFastIselFailStore,"Fast isel fails on Store");
-STATISTIC(NumFastIselFailAtomicCmpXchg,"Fast isel fails on AtomicCmpXchg");
-STATISTIC(NumFastIselFailAtomicRMW,"Fast isel fails on AtomicRWM");
-STATISTIC(NumFastIselFailFence,"Fast isel fails on Frence");
-STATISTIC(NumFastIselFailGetElementPtr,"Fast isel fails on GetElementPtr");
-
-  // Convert instructions...
-STATISTIC(NumFastIselFailTrunc,"Fast isel fails on Trunc");
-STATISTIC(NumFastIselFailZExt,"Fast isel fails on ZExt");
-STATISTIC(NumFastIselFailSExt,"Fast isel fails on SExt");
-STATISTIC(NumFastIselFailFPTrunc,"Fast isel fails on FPTrunc");
-STATISTIC(NumFastIselFailFPExt,"Fast isel fails on FPExt");
-STATISTIC(NumFastIselFailFPToUI,"Fast isel fails on FPToUI");
-STATISTIC(NumFastIselFailFPToSI,"Fast isel fails on FPToSI");
-STATISTIC(NumFastIselFailUIToFP,"Fast isel fails on UIToFP");
-STATISTIC(NumFastIselFailSIToFP,"Fast isel fails on SIToFP");
-STATISTIC(NumFastIselFailIntToPtr,"Fast isel fails on IntToPtr");
-STATISTIC(NumFastIselFailPtrToInt,"Fast isel fails on PtrToInt");
-STATISTIC(NumFastIselFailBitCast,"Fast isel fails on BitCast");
-
-  // Other instructions...
-STATISTIC(NumFastIselFailICmp,"Fast isel fails on ICmp");
-STATISTIC(NumFastIselFailFCmp,"Fast isel fails on FCmp");
-STATISTIC(NumFastIselFailPHI,"Fast isel fails on PHI");
-STATISTIC(NumFastIselFailSelect,"Fast isel fails on Select");
-STATISTIC(NumFastIselFailCall,"Fast isel fails on Call");
-STATISTIC(NumFastIselFailShl,"Fast isel fails on Shl");
-STATISTIC(NumFastIselFailLShr,"Fast isel fails on LShr");
-STATISTIC(NumFastIselFailAShr,"Fast isel fails on AShr");
-STATISTIC(NumFastIselFailVAArg,"Fast isel fails on VAArg");
-STATISTIC(NumFastIselFailExtractElement,"Fast isel fails on ExtractElement");
-STATISTIC(NumFastIselFailInsertElement,"Fast isel fails on InsertElement");
-STATISTIC(NumFastIselFailShuffleVector,"Fast isel fails on ShuffleVector");
-STATISTIC(NumFastIselFailExtractValue,"Fast isel fails on ExtractValue");
-STATISTIC(NumFastIselFailInsertValue,"Fast isel fails on InsertValue");
-STATISTIC(NumFastIselFailLandingPad,"Fast isel fails on LandingPad");
-
-// Intrinsic instructions...
-STATISTIC(NumFastIselFailIntrinsicCall, "Fast isel fails on Intrinsic call");
-STATISTIC(NumFastIselFailSAddWithOverflow,
-          "Fast isel fails on sadd.with.overflow");
-STATISTIC(NumFastIselFailUAddWithOverflow,
-          "Fast isel fails on uadd.with.overflow");
-STATISTIC(NumFastIselFailSSubWithOverflow,
-          "Fast isel fails on ssub.with.overflow");
-STATISTIC(NumFastIselFailUSubWithOverflow,
-          "Fast isel fails on usub.with.overflow");
-STATISTIC(NumFastIselFailSMulWithOverflow,
-          "Fast isel fails on smul.with.overflow");
-STATISTIC(NumFastIselFailUMulWithOverflow,
-          "Fast isel fails on umul.with.overflow");
-STATISTIC(NumFastIselFailFrameaddress, "Fast isel fails on Frameaddress");
-STATISTIC(NumFastIselFailSqrt, "Fast isel fails on sqrt call");
-STATISTIC(NumFastIselFailStackMap, "Fast isel fails on StackMap call");
-STATISTIC(NumFastIselFailPatchPoint, "Fast isel fails on PatchPoint call");
-#endif
-
-static cl::opt<bool>
-EnableFastISelVerbose("fast-isel-verbose", cl::Hidden,
-          cl::desc("Enable verbose messages in the \"fast\" "
-                   "instruction selector"));
 static cl::opt<int> EnableFastISelAbort(
     "fast-isel-abort", cl::Hidden,
     cl::desc("Enable abort calls when \"fast\" instruction selection "
@@ -469,8 +372,6 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
           MachineFunctionProperties::Property::Selected))
     return false;
   // Do some sanity-checking on the command-line options.
-  assert((!EnableFastISelVerbose || TM.Options.EnableFastISel) &&
-         "-fast-isel-verbose requires -fast-isel");
   assert((!EnableFastISelAbort || TM.Options.EnableFastISel) &&
          "-fast-isel-abort > 0 requires -fast-isel");
 
@@ -495,12 +396,13 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
   AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
   LibInfo = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
   GFI = Fn.hasGC() ? &getAnalysis<GCModuleInfo>().getFunctionInfo(Fn) : nullptr;
+  ORE = make_unique<OptimizationRemarkEmitter>(&Fn);
 
   DEBUG(dbgs() << "\n\n\n=== " << Fn.getName() << "\n");
 
   SplitCriticalSideEffectEdges(const_cast<Function &>(Fn));
 
-  CurDAG->init(*MF);
+  CurDAG->init(*MF, *ORE);
   FuncInfo->set(Fn, *MF, CurDAG);
 
   if (UseMBPI && OptLevel != CodeGenOpt::None)
@@ -708,6 +610,21 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
   return true;
 }
 
+static void reportFastISelFailure(MachineFunction &MF,
+                                  OptimizationRemarkEmitter &ORE,
+                                  OptimizationRemarkMissed &R,
+                                  bool ShouldAbort) {
+  // Print the function name explicitly if we don't have a debug location (which
+  // makes the diagnostic less useful) or if we're going to emit a raw error.
+  if (!R.getLocation().isValid() || ShouldAbort)
+    R << (" (in function: " + MF.getName() + ")").str();
+
+  if (ShouldAbort)
+    report_fatal_error(R.getMsg());
+
+  ORE.emit(R);
+}
+
 void SelectionDAGISel::SelectBasicBlock(BasicBlock::const_iterator Begin,
                                         BasicBlock::const_iterator End,
                                         bool &HadTailCall) {
@@ -1164,116 +1081,6 @@ static bool isFoldedOrDeadInstruction(const Instruction *I,
          !FuncInfo->isExportedInst(I); // Exported instrs must be computed.
 }
 
-#ifndef NDEBUG
-// Collect per Instruction statistics for fast-isel misses.  Only those
-// instructions that cause the bail are accounted for.  It does not account for
-// instructions higher in the block.  Thus, summing the per instructions stats
-// will not add up to what is reported by NumFastIselFailures.
-static void collectFailStats(const Instruction *I) {
-  switch (I->getOpcode()) {
-  default: assert(false && "<Invalid operator>");
-
-  // Terminators
-  case Instruction::Ret:         NumFastIselFailRet++; return;
-  case Instruction::Br:          NumFastIselFailBr++; return;
-  case Instruction::Switch:      NumFastIselFailSwitch++; return;
-  case Instruction::IndirectBr:  NumFastIselFailIndirectBr++; return;
-  case Instruction::Invoke:      NumFastIselFailInvoke++; return;
-  case Instruction::Resume:      NumFastIselFailResume++; return;
-  case Instruction::Unreachable: NumFastIselFailUnreachable++; return;
-
-  // Standard binary operators...
-  case Instruction::Add:  NumFastIselFailAdd++; return;
-  case Instruction::FAdd: NumFastIselFailFAdd++; return;
-  case Instruction::Sub:  NumFastIselFailSub++; return;
-  case Instruction::FSub: NumFastIselFailFSub++; return;
-  case Instruction::Mul:  NumFastIselFailMul++; return;
-  case Instruction::FMul: NumFastIselFailFMul++; return;
-  case Instruction::UDiv: NumFastIselFailUDiv++; return;
-  case Instruction::SDiv: NumFastIselFailSDiv++; return;
-  case Instruction::FDiv: NumFastIselFailFDiv++; return;
-  case Instruction::URem: NumFastIselFailURem++; return;
-  case Instruction::SRem: NumFastIselFailSRem++; return;
-  case Instruction::FRem: NumFastIselFailFRem++; return;
-
-  // Logical operators...
-  case Instruction::And: NumFastIselFailAnd++; return;
-  case Instruction::Or:  NumFastIselFailOr++; return;
-  case Instruction::Xor: NumFastIselFailXor++; return;
-
-  // Memory instructions...
-  case Instruction::Alloca:        NumFastIselFailAlloca++; return;
-  case Instruction::Load:          NumFastIselFailLoad++; return;
-  case Instruction::Store:         NumFastIselFailStore++; return;
-  case Instruction::AtomicCmpXchg: NumFastIselFailAtomicCmpXchg++; return;
-  case Instruction::AtomicRMW:     NumFastIselFailAtomicRMW++; return;
-  case Instruction::Fence:         NumFastIselFailFence++; return;
-  case Instruction::GetElementPtr: NumFastIselFailGetElementPtr++; return;
-
-  // Convert instructions...
-  case Instruction::Trunc:    NumFastIselFailTrunc++; return;
-  case Instruction::ZExt:     NumFastIselFailZExt++; return;
-  case Instruction::SExt:     NumFastIselFailSExt++; return;
-  case Instruction::FPTrunc:  NumFastIselFailFPTrunc++; return;
-  case Instruction::FPExt:    NumFastIselFailFPExt++; return;
-  case Instruction::FPToUI:   NumFastIselFailFPToUI++; return;
-  case Instruction::FPToSI:   NumFastIselFailFPToSI++; return;
-  case Instruction::UIToFP:   NumFastIselFailUIToFP++; return;
-  case Instruction::SIToFP:   NumFastIselFailSIToFP++; return;
-  case Instruction::IntToPtr: NumFastIselFailIntToPtr++; return;
-  case Instruction::PtrToInt: NumFastIselFailPtrToInt++; return;
-  case Instruction::BitCast:  NumFastIselFailBitCast++; return;
-
-  // Other instructions...
-  case Instruction::ICmp:           NumFastIselFailICmp++; return;
-  case Instruction::FCmp:           NumFastIselFailFCmp++; return;
-  case Instruction::PHI:            NumFastIselFailPHI++; return;
-  case Instruction::Select:         NumFastIselFailSelect++; return;
-  case Instruction::Call: {
-    if (auto const *Intrinsic = dyn_cast<IntrinsicInst>(I)) {
-      switch (Intrinsic->getIntrinsicID()) {
-      default:
-        NumFastIselFailIntrinsicCall++; return;
-      case Intrinsic::sadd_with_overflow:
-        NumFastIselFailSAddWithOverflow++; return;
-      case Intrinsic::uadd_with_overflow:
-        NumFastIselFailUAddWithOverflow++; return;
-      case Intrinsic::ssub_with_overflow:
-        NumFastIselFailSSubWithOverflow++; return;
-      case Intrinsic::usub_with_overflow:
-        NumFastIselFailUSubWithOverflow++; return;
-      case Intrinsic::smul_with_overflow:
-        NumFastIselFailSMulWithOverflow++; return;
-      case Intrinsic::umul_with_overflow:
-        NumFastIselFailUMulWithOverflow++; return;
-      case Intrinsic::frameaddress:
-        NumFastIselFailFrameaddress++; return;
-      case Intrinsic::sqrt:
-          NumFastIselFailSqrt++; return;
-      case Intrinsic::experimental_stackmap:
-        NumFastIselFailStackMap++; return;
-      case Intrinsic::experimental_patchpoint_void: // fall-through
-      case Intrinsic::experimental_patchpoint_i64:
-        NumFastIselFailPatchPoint++; return;
-      }
-    }
-    NumFastIselFailCall++;
-    return;
-  }
-  case Instruction::Shl:            NumFastIselFailShl++; return;
-  case Instruction::LShr:           NumFastIselFailLShr++; return;
-  case Instruction::AShr:           NumFastIselFailAShr++; return;
-  case Instruction::VAArg:          NumFastIselFailVAArg++; return;
-  case Instruction::ExtractElement: NumFastIselFailExtractElement++; return;
-  case Instruction::InsertElement:  NumFastIselFailInsertElement++; return;
-  case Instruction::ShuffleVector:  NumFastIselFailShuffleVector++; return;
-  case Instruction::ExtractValue:   NumFastIselFailExtractValue++; return;
-  case Instruction::InsertValue:    NumFastIselFailInsertValue++; return;
-  case Instruction::LandingPad:     NumFastIselFailLandingPad++; return;
-  }
-}
-#endif // NDEBUG
-
 /// Set up SwiftErrorVals by going through the function. If the function has
 /// swifterror argument, it will be the first entry.
 static void setupSwiftErrorVals(const Function &Fn, const TargetLowering *TLI,
@@ -1491,8 +1298,13 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
       FastISelFailed = true;
       // Fast isel failed to lower these arguments
       ++NumFastIselFailLowerArguments;
-      if (EnableFastISelAbort > 1)
-        report_fatal_error("FastISel didn't lower all arguments");
+
+      OptimizationRemarkMissed R("sdagisel", "FastISelFailure",
+                                 Fn.getSubprogram(),
+                                 &Fn.getEntryBlock());
+      R << "FastISel didn't lower all arguments: "
+        << ore::NV("Prototype", Fn.getType());
+      reportFastISelFailure(*MF, *ORE, R, EnableFastISelAbort > 1);
 
       // Use SelectionDAG argument lowering
       LowerArguments(Fn);
@@ -1601,22 +1413,22 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
           continue;
         }
 
-#ifndef NDEBUG
-        if (EnableFastISelVerbose2)
-          collectFailStats(Inst);
-#endif
-
         // Then handle certain instructions as single-LLVM-Instruction blocks.
         if (isa<CallInst>(Inst)) {
+          OptimizationRemarkMissed R("sdagisel", "FastISelFailure",
+                                     Inst->getDebugLoc(), LLVMBB);
+
+          R << "FastISel missed call";
+
+          if (R.isEnabled() || EnableFastISelAbort) {
+            std::string InstStrStorage;
+            raw_string_ostream InstStr(InstStrStorage);
+            InstStr << *Inst;
 
-          if (EnableFastISelVerbose || EnableFastISelAbort) {
-            dbgs() << "FastISel missed call: ";
-            Inst->print(dbgs());
+            R << ": " << InstStr.str();
           }
-          if (EnableFastISelAbort > 2)
-            // FastISel selector couldn't handle something and bailed.
-            // For the purpose of debugging, just abort.
-            report_fatal_error("FastISel didn't select the entire block");
+
+          reportFastISelFailure(*MF, *ORE, R, EnableFastISelAbort > 2);
 
           if (!Inst->getType()->isVoidTy() && !Inst->getType()->isTokenTy() &&
               !Inst->use_empty()) {
@@ -1645,22 +1457,27 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
           continue;
         }
 
+        OptimizationRemarkMissed R("sdagisel", "FastISelFailure",
+                                   Inst->getDebugLoc(), LLVMBB);
+
         bool ShouldAbort = EnableFastISelAbort;
-        if (EnableFastISelVerbose || EnableFastISelAbort) {
-          if (isa<TerminatorInst>(Inst)) {
-            // Use a different message for terminator misses.
-            dbgs() << "FastISel missed terminator: ";
-            // Don't abort unless for terminator unless the level is really high
-            ShouldAbort = (EnableFastISelAbort > 2);
-          } else {
-            dbgs() << "FastISel miss: ";
-          }
-          Inst->print(dbgs());
+        if (isa<TerminatorInst>(Inst)) {
+          // Use a different message for terminator misses.
+          R << "FastISel missed terminator";
+          // Don't abort for terminator unless the level is really high
+          ShouldAbort = (EnableFastISelAbort > 2);
+        } else {
+          R << "FastISel missed";
         }
-        if (ShouldAbort)
-          // FastISel selector couldn't handle something and bailed.
-          // For the purpose of debugging, just abort.
-          report_fatal_error("FastISel didn't select the entire block");
+
+        if (R.isEnabled() || EnableFastISelAbort) {
+          std::string InstStrStorage;
+          raw_string_ostream InstStr(InstStrStorage);
+          InstStr << *Inst;
+          R << ": " << InstStr.str();
+        }
+
+        reportFastISelFailure(*MF, *ORE, R, ShouldAbort);
 
         NumFastIselFailures += NumFastIselRemaining;
         break;