[llvm] [NFC][InstrInfoEmitter] Include location of inst definition in comment (PR #156927)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-tablegen

Author: Rahul Joshi (jurahul)

<details>
<summary>Changes</summary>

Print the source location of the instruction definition in comment next to the enum value for each instruction. To make this more readable, change formatting of the instruction enums to be better aligned.

Example output:

```
    VLD4qWB_register_Asm_8                 = 573, // (ARMInstrNEON.td:8849)
    VMOVD0                                 = 574, // (ARMInstrNEON.td:6337)
    VMOVDcc                                = 575, // (ARMInstrVFP.td:2466)
    VMOVHcc                                = 576, // (ARMInstrVFP.td:2474)
    VMOVQ0                                 = 577, // (ARMInstrNEON.td:6341)
```

---
Full diff: https://github.com/llvm/llvm-project/pull/156927.diff


2 Files Affected:

- (modified) llvm/utils/TableGen/Common/CodeGenInstruction.h (+2) 
- (modified) llvm/utils/TableGen/InstrInfoEmitter.cpp (+20-6) 


``````````diff
diff --git a/llvm/utils/TableGen/Common/CodeGenInstruction.h b/llvm/utils/TableGen/Common/CodeGenInstruction.h
index 9372614f26e1a..ed0bfa7098eb7 100644
--- a/llvm/utils/TableGen/Common/CodeGenInstruction.h
+++ b/llvm/utils/TableGen/Common/CodeGenInstruction.h
@@ -320,6 +320,8 @@ class CodeGenInstruction {
     return RV && isa<DagInit>(RV->getValue());
   }
 
+  StringRef getName() const { return TheDef->getName(); }
+
 private:
   bool isOperandImpl(StringRef OpListName, unsigned i,
                      StringRef PropertyName) const;
diff --git a/llvm/utils/TableGen/InstrInfoEmitter.cpp b/llvm/utils/TableGen/InstrInfoEmitter.cpp
index 26d93fc13c9ba..afbd64e4c7012 100644
--- a/llvm/utils/TableGen/InstrInfoEmitter.cpp
+++ b/llvm/utils/TableGen/InstrInfoEmitter.cpp
@@ -25,6 +25,8 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Casting.h"
+#include "llvm/Support/FormattedStream.h"
+#include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
@@ -1289,8 +1291,9 @@ void InstrInfoEmitter::emitRecord(
 
 // emitEnums - Print out enum values for all of the instructions.
 void InstrInfoEmitter::emitEnums(
-    raw_ostream &OS,
+    raw_ostream &RawOS,
     ArrayRef<const CodeGenInstruction *> NumberedInstructions) {
+  formatted_raw_ostream OS(RawOS);
   OS << "#ifdef GET_INSTRINFO_ENUM\n";
   OS << "#undef GET_INSTRINFO_ENUM\n";
 
@@ -1302,18 +1305,29 @@ void InstrInfoEmitter::emitEnums(
 
   OS << "namespace llvm::" << Namespace << " {\n";
 
+  auto II = llvm::max_element(
+      NumberedInstructions,
+      [](const CodeGenInstruction *InstA, const CodeGenInstruction *InstB) {
+        return InstA->getName().size() < InstB->getName().size();
+      });
+  size_t MaxNameSize = (*II)->getName().size();
+
   OS << "  enum {\n";
-  for (const CodeGenInstruction *Inst : NumberedInstructions)
-    OS << "    " << Inst->TheDef->getName()
-       << "\t= " << Target.getInstrIntValue(Inst->TheDef) << ",\n";
+  for (const CodeGenInstruction *Inst : NumberedInstructions) {
+    OS << "    " << Inst->TheDef->getName();
+    OS.PadToColumn(MaxNameSize + 5);
+    OS << " = " << Target.getInstrIntValue(Inst->TheDef) << ", // (";
+    OS << SrcMgr.getFormattedLocationNoOffset(Inst->TheDef->getLoc().front())
+       << ")\n";
+  }
   OS << "    INSTRUCTION_LIST_END = " << NumberedInstructions.size() << '\n';
-  OS << "  };\n\n";
+  OS << "  };\n";
   OS << "} // end namespace llvm::" << Namespace << '\n';
   OS << "#endif // GET_INSTRINFO_ENUM\n\n";
 
   OS << "#ifdef GET_INSTRINFO_SCHED_ENUM\n";
   OS << "#undef GET_INSTRINFO_SCHED_ENUM\n";
-  OS << "namespace llvm::" << Namespace << "::Sched {\n\n";
+  OS << "namespace llvm::" << Namespace << "::Sched {\n";
   OS << "  enum {\n";
   auto ExplictClasses = SchedModels.explicitSchedClasses();
   for (const auto &[Idx, Class] : enumerate(ExplictClasses))

``````````

</details>


https://github.com/llvm/llvm-project/pull/156927