[llvm] [MCA] New option -scheduling-info (PR #130574)

[Min-Yih Hsu via llvm-commits]

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@@ -14,13 +14,45 @@
 #include "Views/InstructionInfoView.h"
 #include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/JSON.h"
+#include "llvm/Support/WithColor.h"
 
 namespace llvm {
 namespace mca {
 
+void InstructionInfoView::getComment(const MCInst &MCI,
+                                     std::string &CommentString) const {
+  StringRef s = MCI.getLoc().getPointer();
+  std::string InstrStr;
+  size_t pos = 0, pos_cmt = 0;
+
+  // Recognized comments are after assembly instructions on the same line.
+  // It is usefull to add in comment scheduling information from architecture
+  // specification.
+  // '#' comment mark is not supported by llvm-mca
+
+  CommentString = "";
+  if ((pos = s.find("\n")) != std::string::npos) {
+    InstrStr = s.substr(0, pos);
+    // C style comment
+    if (((pos_cmt = InstrStr.find("/*")) != std::string::npos) &&
+        ((pos = InstrStr.find("*/")) != std::string::npos)) {
+      CommentString = InstrStr.substr(pos_cmt, pos);
+      return;
+    }
+    // C++ style comment
+    if ((pos_cmt = InstrStr.find("//")) != std::string::npos) {
+      CommentString = InstrStr.substr(pos_cmt, pos);
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mshockwave wrote:

I'm not sure why you put `pos` here: if `pos` was not updated by line 38, then it'll be a position of _another_ string, `s`, which is not ideal. Since you already chop off new line character from `s`, I don't think `InstrStr` has any of them. So I think you can just use `InstrStr.substr(pos_cmt)` here.

https://github.com/llvm/llvm-project/pull/130574