[DiagnosticInfo] Add a diagnostic class for the fallback of ISel.

This will be used to warm when we fallback in GlobalISel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280271 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/DiagnosticInfo.h

@@ -54,6 +54,7 @@ enum DiagnosticKind {
   DK_Linker,
   DK_DebugMetadataVersion,
   DK_DebugMetadataInvalid,
+  DK_ISelFallback,
   DK_SampleProfile,
   DK_OptimizationRemark,
   DK_OptimizationRemarkMissed,
@@ -584,6 +585,25 @@ class DiagnosticInfoMIRParser : public DiagnosticInfo {
   }
 };
 
+/// Diagnostic information for ISel fallback path.
+class DiagnosticInfoISelFallback : public DiagnosticInfo {
+  /// The function that is concerned by this diagnostic.
+  const Function &Fn;
+
+public:
+  DiagnosticInfoISelFallback(const Function &Fn,
+                             DiagnosticSeverity Severity = DS_Warning)
+      : DiagnosticInfo(DK_ISelFallback, Severity), Fn(Fn) {}
+
+  const Function &getFunction() const { return Fn; }
+
+  void print(DiagnosticPrinter &DP) const override;
+
+  static bool classof(const DiagnosticInfo *DI) {
+    return DI->getKind() == DK_ISelFallback;
+  }
+};
+
 // Create wrappers for C Binding types (see CBindingWrapping.h).
 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(DiagnosticInfo, LLVMDiagnosticInfoRef)
 

lib/IR/DiagnosticInfo.cpp

@@ -262,3 +262,7 @@ void llvm::emitLoopInterleaveWarning(LLVMContext &Ctx, const Function &Fn,
   Ctx.diagnose(DiagnosticInfoOptimizationFailure(
       Fn, DLoc, Twine("loop not interleaved: " + Msg)));
 }
+
+void DiagnosticInfoISelFallback::print(DiagnosticPrinter &DP) const {
+  DP << "Instruction selection used fallback path for " << getFunction();
+}