Add an instruction marker field to the ExtraInfo in MachineInstrs.

Summary:
Add instruction marker to MachineInstr ExtraInfo. This does almost the
same thing as Pre/PostInstrSymbols, except that it doesn't create a label until
printing instructions. This allows for labels to be put around instructions that
are deleted/duplicated somewhere.

Also undo the workaround in r375137.

Reviewers: rnk

Subscribers: MatzeB, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69136

3 files changed, 28 insertions, 22 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 73c53d6c4af..513361e1341 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1065,13 +1065,9 @@ void AsmPrinter::EmitFunctionBody() {
         ++NumInstsInFunction;
       }
 
-      // If there is a pre-instruction symbol, emit a label for it here. If the
-      // instruction was duplicated and the label has already been emitted,
-      // don't re-emit the same label.
-      // FIXME: Consider strengthening that to an assertion.
+      // If there is a pre-instruction symbol, emit a label for it here.
       if (MCSymbol *S = MI.getPreInstrSymbol())
-        if (S->isUndefined())
-          OutStreamer->EmitLabel(S);
+        OutStreamer->EmitLabel(S);
 
       if (ShouldPrintDebugScopes) {
         for (const HandlerInfo &HI : Handlers) {
@@ -1124,13 +1120,9 @@ void AsmPrinter::EmitFunctionBody() {
         break;
       }
 
-      // If there is a post-instruction symbol, emit a label for it here.  If
-      // the instruction was duplicated and the label has already been emitted,
-      // don't re-emit the same label.
-      // FIXME: Consider strengthening that to an assertion.
+      // If there is a post-instruction symbol, emit a label for it here.
       if (MCSymbol *S = MI.getPostInstrSymbol())
-        if (S->isUndefined())
-          OutStreamer->EmitLabel(S);
+        OutStreamer->EmitLabel(S);
 
       if (ShouldPrintDebugScopes) {
         for (const HandlerInfo &HI : Handlers) {
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index c6457f3626d..62ad356e7f8 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -1100,14 +1100,8 @@ void CodeViewDebug::emitDebugInfoForFunction(const Function *GV,
     }
 
     for (auto HeapAllocSite : FI.HeapAllocSites) {
-      MCSymbol *BeginLabel = std::get<0>(HeapAllocSite);
-      MCSymbol *EndLabel = std::get<1>(HeapAllocSite);
-
-      // The labels might not be defined if the instruction was replaced
-      // somewhere in the codegen pipeline.
-      if (!BeginLabel->isDefined() || !EndLabel->isDefined())
-        continue;
-
+      const MCSymbol *BeginLabel = std::get<0>(HeapAllocSite);
+      const MCSymbol *EndLabel = std::get<1>(HeapAllocSite);
       const DIType *DITy = std::get<2>(HeapAllocSite);
       MCSymbol *HeapAllocEnd = beginSymbolRecord(SymbolKind::S_HEAPALLOCSITE);
       OS.AddComment("Call site offset");
@@ -1427,6 +1421,16 @@ void CodeViewDebug::beginFunctionImpl(const MachineFunction *MF) {
     DebugLoc FnStartDL = PrologEndLoc.getFnDebugLoc();
     maybeRecordLocation(FnStartDL, MF);
   }
+
+  // Find heap alloc sites and emit labels around them.
+  for (const auto &MBB : *MF) {
+    for (const auto &MI : MBB) {
+      if (MI.getHeapAllocMarker()) {
+        requestLabelBeforeInsn(&MI);
+        requestLabelAfterInsn(&MI);
+      }
+    }
+  }
 }
 
 static bool shouldEmitUdt(const DIType *T) {
@@ -2850,8 +2854,18 @@ void CodeViewDebug::endFunctionImpl(const MachineFunction *MF) {
     return;
   }
 
+  // Find heap alloc sites and add to list.
+  for (const auto &MBB : *MF) {
+    for (const auto &MI : MBB) {
+      if (MDNode *MD = MI.getHeapAllocMarker()) {
+        CurFn->HeapAllocSites.push_back(std::make_tuple(getLabelBeforeInsn(&MI),
+                                                        getLabelAfterInsn(&MI),
+                                                        dyn_cast<DIType>(MD)));
+      }
+    }
+  }
+
   CurFn->Annotations = MF->getCodeViewAnnotations();
-  CurFn->HeapAllocSites = MF->getCodeViewHeapAllocSites();
 
   CurFn->End = Asm->getFunctionEnd();
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
index 7ffd77926cf..b56b9047e1a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
@@ -148,7 +148,7 @@ class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {
     SmallVector<LexicalBlock *, 1> ChildBlocks;
 
     std::vector<std::pair<MCSymbol *, MDNode *>> Annotations;
-    std::vector<std::tuple<MCSymbol *, MCSymbol *, const DIType *>>
+    std::vector<std::tuple<const MCSymbol *, const MCSymbol *, const DIType *>>
         HeapAllocSites;
 
     const MCSymbol *Begin = nullptr;