[DebugInfo][InstrRef] Prettyprint metadata

[aheejin]

Summary

Some metadata prettyprinting, including variable prettyprinting and
debug line info comments, is currently only supported for DBG_VALUE.
This allows DBG_INSTR_REF can be printed in the same way.

[jmorse]

Yes please! (LGTM)

llvm/lib/CodeGen/MachineInstr.cpp

void MachineInstr::print(raw_ostream &OS, ModuleSlotTracker &MST,
   }
 
   for (unsigned i = StartOp, e = getNumOperands(); i != e; ++i) {
     const MachineOperand &MO = getOperand(i);
 
     if (FirstOp) FirstOp = false; else OS << ",";
     OS << " ";
 
-    if (isDebugValue() && MO.isMetadata()) {
+    if (isDebugValueLike() && MO.isMetadata()) {
       // Pretty print DBG_VALUE* instructions.
       auto *DIV = dyn_cast<DILocalVariable>(MO.getMetadata());
       if (DIV && !DIV->getName().empty())
         OS << "!\"" << DIV->getName() << '\"';
       else {
         LLT TypeToPrint = MRI ? getTypeToPrint(i, PrintedTypes, *MRI) : LLT{};
         unsigned TiedOperandIdx = getTiedOperandIdx(i);
         MO.print(OS, MST, TypeToPrint, i, /*PrintDef=*/true, IsStandalone,
if (!HaveSemi) {
       OS << ';';
       HaveSemi = true;
     }
     OS << ' ';
     DL.print(OS);
   }
 
   // Print extra comments for DEBUG_VALUE.
-  if (isDebugValue() && getDebugVariableOp().isMetadata()) {
+  if (isDebugValueLike() && getDebugVariableOp().isMetadata()) {
     if (!HaveSemi) {
       OS << ";";
       HaveSemi = true;
     }
     auto *DV = getDebugVariable();
     OS << " line no:" <<  DV->getLine();
     if (isIndirectDebugValue())
       OS << " indirect";

llvm/test/DebugInfo/MIR/InstrRef/pretty-print.mir

+# RUN: llc %s -march=x86-64 -run-pass=machineverifier -print-after-all -o /dev/null -experimental-debug-variable-locations 2>&1 | FileCheck %s
+# REQUIRES: x86-registered-target
+--- |
+  define void @pretty_print_test() {
+    unreachable
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!2, !3, !4}
+
+  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, emissionKind: FullDebug)
+  !1 = !DIFile(filename: "test.c", directory: "")
+  !2 = !{i32 7, !"Dwarf Version", i32 5}
+  !3 = !{i32 2, !"Debug Info Version", i32 3}
+  !4 = !{i32 1, !"wchar_size", i32 4}
+  !6 = distinct !DISubprogram(name: "pretty_print_test", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
+  !7 = !DISubroutineType(types: !8)
+  !8 = !{null}
+  !9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !10 = !DILocalVariable(name: "var", scope: !6, file: !1, line: 2, type: !9)
+...
+---
+name: pretty_print_test
+tracksRegLiveness: true
+debugInstrRef: true
+body:  |
+  bb.0:
+    %0:gr64 = MOV64ri 1, debug-instr-number 1
+    ; CHECK: DBG_INSTR_REF !"var", {{.*}}; test.c:10 line no:2
+    DBG_INSTR_REF !10, !DIExpression(), dbg-instr-ref(1, 0), debug-location !DILocation(line:10, scope:!6)
+    RET 0
+...