Add option to print entire function instead of just the loops for loop passes

Author: akshayrdeodhar

llvm/include/llvm/IR/PrintPasses.h

@@ -51,6 +51,9 @@ std::vector<std::string> printAfterPasses();
 // Returns true if we should always print the entire module.
 bool forcePrintModuleIR();
 
+// Returns true if we should print the entire function for loop passes.
+bool forcePrintFuncIR();
+
 // Return true if -filter-passes is empty or contains the pass name.
 bool isPassInPrintList(StringRef PassName);
 bool isFilterPassesEmpty();

llvm/lib/Analysis/LoopInfo.cpp

@@ -999,6 +999,18 @@ void llvm::printLoop(Loop &L, raw_ostream &OS, const std::string &Banner) {
     return;
   }
 
+  if (forcePrintFuncIR()) {
+    // handling -print-loop-func-scope.
+    // -print-module-scope overrides this.
+    OS << Banner << " (loop: ";
+    L.getHeader()->printAsOperand(OS, false);
+    OS << ")\n";
+
+    // printing whole function.
+    OS << *L.getHeader()->getParent();
+    return;
+  }
+
   OS << Banner;
 
   auto *PreHeader = L.getLoopPreheader();

llvm/lib/IR/PrintPasses.cpp

@@ -88,6 +88,12 @@ static cl::opt<bool>
                               "always print a module IR"),
                      cl::init(false), cl::Hidden);
 
+static cl::opt<bool>
+    LoopPrintFuncScope("print-loop-func-scope",
+                       cl::desc("When printing IR for print-[before|after]{-all} "
+                                "for a loop pass, always print function IR"),
+                       cl::init(false), cl::Hidden);
+
 // See the description for -print-changed for an explanation of the use
 // of this option.
 static cl::list<std::string> FilterPasses(
@@ -141,6 +147,8 @@ std::vector<std::string> llvm::printAfterPasses() {
 
 bool llvm::forcePrintModuleIR() { return PrintModuleScope; }
 
+bool llvm::forcePrintFuncIR() { return LoopPrintFuncScope; }
+
 bool llvm::isPassInPrintList(StringRef PassName) {
   static std::unordered_set<std::string> Set(FilterPasses.begin(),
                                              FilterPasses.end());