Changed XXX to FIXME, and added comment to the README file

llvm-svn: 43359

llvm/lib/CodeGen/BranchFolding.cpp

@@ -272,7 +272,7 @@ static unsigned ComputeCommonTailLength(MachineBasicBlock *MBB1,
   while (I1 != MBB1->begin() && I2 != MBB2->begin()) {
     --I1; --I2;
     if (!I1->isIdenticalTo(I2) || 
-        // XXX: This check is dubious. It's used to get around a problem where
+        // FIXME: This check is dubious. It's used to get around a problem where
         // people incorrectly expect inline asm directives to remain in the same
         // relative order. This is untenable because normal compiler
         // optimizations (like this one) may reorder and/or merge these

llvm/lib/CodeGen/README.txt

@@ -179,3 +179,11 @@ work.
 
 The ocaml frametable structure supports liveness information. It would be good
 to support it.
+
+//===---------------------------------------------------------------------===//
+
+The FIXME in ComputeCommonTailLength in BranchFolding.cpp needs to be
+revisited. The check is there to work around a misuse of directives in inline
+assembly.
+
+//===---------------------------------------------------------------------===//