[llvm] [LLVM-Tablegen] Pretty Printing Arguments in LLVM Intrinsics (PR #162629)

[Rahul Joshi via llvm-commits]

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@@ -4581,12 +4582,38 @@ void AssemblyWriter::printInstruction(const Instruction &I) {
     Out << ' ';
     writeOperand(Operand, false);
     Out << '(';
+    bool HasPrettyPrintedArgs =
+        isa<IntrinsicInst>(CI) &&
+        Intrinsic::hasPrettyPrintedArgs(CI->getIntrinsicID());
+
     ListSeparator LS;
-    for (unsigned op = 0, Eop = CI->arg_size(); op < Eop; ++op) {
-      Out << LS;
-      writeParamOperand(CI->getArgOperand(op), PAL.getParamAttrs(op));
-    }
+    if (HasPrettyPrintedArgs) {
+      Function *CalledFunc = CI->getCalledFunction();
+      auto PrintArgComment = [&](unsigned ArgNo) {
+        const Constant *ConstArg = dyn_cast<Constant>(CI->getArgOperand(ArgNo));
+        if (!ConstArg)
+          return;
+        std::string ArgComment;
+        raw_string_ostream ArgCommentStream(ArgComment);
+        Intrinsic::ID IID = CalledFunc->getIntrinsicID();
+        Intrinsic::printImmArg(IID, ArgNo, ArgCommentStream, ConstArg);
+        if (ArgComment.empty())
+          return;
+        Out << "/* " << ArgComment << " */ ";
+      };
 
+      for (unsigned ArgNo = 0, NumArgs = CI->arg_size(); ArgNo < NumArgs;
+           ++ArgNo) {
+        Out << LS;
+        PrintArgComment(ArgNo);
+        writeParamOperand(CI->getArgOperand(ArgNo), PAL.getParamAttrs(ArgNo));
+      }
+    } else {
+      for (unsigned op = 0, Eop = CI->arg_size(); op < Eop; ++op) {
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jurahul wrote:

nit: Can you rename this to use ArgNo and NumArgs similar to the loop above?

https://github.com/llvm/llvm-project/pull/162629