[WebAssembly] Use TargetIndex operands in DbgValue to track WebAssembly operands locations

Extends DWARF expression language to express locals/globals locations. (via
target-index operands atm) (possible variants are: non-virtual registers
or address spaces)

The WebAssemblyExplicitLocals can replace virtual registers to targertindex
operand type at the time when WebAssembly backend introduces
{get,set,tee}_local instead of corresponding virtual registers.

Reviewed By: aprantl, dschuff

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D52634

6 files changed, 33 insertions, 0 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssembly.h b/llvm/lib/Target/WebAssembly/WebAssembly.h
index fcbd0a5082f..fcd48e0096b 100644
--- a/llvm/lib/Target/WebAssembly/WebAssembly.h
+++ b/llvm/lib/Target/WebAssembly/WebAssembly.h
@@ -79,6 +79,10 @@ void initializeWebAssemblyRegNumberingPass(PassRegistry &);
 void initializeWebAssemblyPeepholePass(PassRegistry &);
 void initializeWebAssemblyCallIndirectFixupPass(PassRegistry &);
 
+namespace WebAssembly {
+enum TargetIndex { TI_LOCAL_START, TI_GLOBAL_START, TI_OPERAND_STACK_START };
+} // end namespace WebAssembly
+
 } // end namespace llvm
 
 #endif
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp
index 579377c9a5d..114a50a3055 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "WebAssemblyDebugValueManager.h"
+#include "WebAssembly.h"
 #include "WebAssemblyMachineFunctionInfo.h"
 #include "llvm/CodeGen/MachineInstr.h"
 
@@ -43,3 +44,10 @@ void WebAssemblyDebugValueManager::clone(MachineInstr *Insert,
     MBB->insert(Insert, Clone);
   }
 }
+
+void WebAssemblyDebugValueManager::replaceWithLocal(unsigned LocalId) {
+  for (auto *DBI : DbgValues) {
+    MachineOperand &Op = DBI->getOperand(0);
+    Op.ChangeToTargetIndex(llvm::WebAssembly::TI_LOCAL_START, LocalId);
+  }
+}
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.h b/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.h
index 06e8805b5ad..7eae3cb5feb 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.h
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.h
@@ -30,6 +30,7 @@ public:
   void move(MachineInstr *Insert);
   void updateReg(unsigned Reg);
   void clone(MachineInstr *Insert, unsigned NewReg);
+  void replaceWithLocal(unsigned LocalId);
 };
 
 } // end namespace llvm
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp
index ef75bb21531..acbd4c9921b 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp
@@ -17,6 +17,7 @@
 
 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
 #include "WebAssembly.h"
+#include "WebAssemblyDebugValueManager.h"
 #include "WebAssemblyMachineFunctionInfo.h"
 #include "WebAssemblySubtarget.h"
 #include "WebAssemblyUtilities.h"
@@ -261,6 +262,8 @@ bool WebAssemblyExplicitLocals::runOnMachineFunction(MachineFunction &MF) {
             .addImm(LocalId)
             .addReg(MI.getOperand(2).getReg());
 
+        WebAssemblyDebugValueManager(&MI).replaceWithLocal(LocalId);
+
         MI.eraseFromParent();
         Changed = true;
         continue;
@@ -290,6 +293,9 @@ bool WebAssemblyExplicitLocals::runOnMachineFunction(MachineFunction &MF) {
           } else {
             unsigned LocalId = getLocalId(Reg2Local, CurLocal, OldReg);
             unsigned Opc = getLocalSetOpcode(RC);
+
+            WebAssemblyDebugValueManager(&MI).replaceWithLocal(LocalId);
+
             BuildMI(MBB, InsertPt, MI.getDebugLoc(), TII->get(Opc))
                 .addImm(LocalId)
                 .addReg(NewReg);
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
index b60fd6f687f..221dacaf821 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
@@ -14,6 +14,7 @@
 
 #include "WebAssemblyInstrInfo.h"
 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
+#include "WebAssembly.h"
 #include "WebAssemblyMachineFunctionInfo.h"
 #include "WebAssemblySubtarget.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
@@ -230,3 +231,12 @@ bool WebAssemblyInstrInfo::reverseBranchCondition(
   Cond.front() = MachineOperand::CreateImm(!Cond.front().getImm());
   return false;
 }
+
+ArrayRef<std::pair<int, const char *>>
+WebAssemblyInstrInfo::getSerializableTargetIndices() const {
+  static const std::pair<int, const char *> TargetIndices[] = {
+      {WebAssembly::TI_LOCAL_START, "wasm-local-start"},
+      {WebAssembly::TI_GLOBAL_START, "wasm-global-start"},
+      {WebAssembly::TI_OPERAND_STACK_START, "wasm-operator-stack-start"}};
+  return makeArrayRef(TargetIndices);
+}
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.h b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.h
index cca8b395b6f..5762fd964c2 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.h
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.h
@@ -16,6 +16,7 @@
 #define LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYINSTRINFO_H
 
 #include "WebAssemblyRegisterInfo.h"
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
 
 #define GET_INSTRINFO_HEADER
@@ -64,6 +65,9 @@ public:
                         int *BytesAdded = nullptr) const override;
   bool
   reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
+
+  ArrayRef<std::pair<int, const char *>>
+  getSerializableTargetIndices() const override;
 };
 
 } // end namespace llvm