[Libomptarget] Do not check for valid binaries twice.

The only RTLs that get added to the `UsedRTLs` list have already been
checked is they were valid binaries. We shouldn't need to do this again
when we unregister all the used binaries as they wouldn't have been used
if they were invalid anyway. Let me know if I'm incorrect in this
assumption.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D131443

Author: jhuber6

openmp/libomptarget/include/rtl.h

@@ -13,6 +13,8 @@
 #ifndef _OMPTARGET_RTL_H
 #define _OMPTARGET_RTL_H
 
+#include "omptarget.h"
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/DynamicLibrary.h"
 
@@ -127,6 +129,8 @@ struct RTLInfoTy {
   // Are there images associated with this RTL.
   bool IsUsed = false;
 
+  llvm::DenseSet<const __tgt_device_image *> UsedImages;
+
   // Mutex for thread-safety when calling RTL interface functions.
   // It is easier to enforce thread-safety at the libomptarget level,
   // so that developers of new RTLs do not have to worry about it.

openmp/libomptarget/src/rtl.cpp

@@ -479,6 +479,8 @@ void RTLsTy::registerLib(__tgt_bin_desc *Desc) {
       DP("Registering image " DPxMOD " with RTL %s!\n", DPxPTR(Img->ImageStart),
          R.RTLName.c_str());
       registerImageIntoTranslationTable(TransTable, R, Img);
+      R.UsedImages.insert(Img);
+
       PM->TrlTblMtx.unlock();
       FoundRTL = &R;
 
@@ -506,7 +508,6 @@ void RTLsTy::unregisterLib(__tgt_bin_desc *Desc) {
   for (auto &ImageAndInfo : PM->Images) {
     // Obtain the image and information that was previously extracted.
     __tgt_device_image *Img = &ImageAndInfo.first;
-    __tgt_image_info *Info = &ImageAndInfo.second;
 
     RTLInfoTy *FoundRTL = NULL;
 
@@ -516,20 +517,9 @@ void RTLsTy::unregisterLib(__tgt_bin_desc *Desc) {
 
       assert(R->IsUsed && "Expecting used RTLs.");
 
-      if (R->is_valid_binary_info) {
-        if (!R->is_valid_binary_info(Img, Info)) {
-          DP("Image " DPxMOD " is NOT compatible with RTL %s!\n",
-             DPxPTR(Img->ImageStart), R->RTLName.c_str());
-          continue;
-        }
-      } else if (!R->is_valid_binary(Img)) {
-        DP("Image " DPxMOD " is NOT compatible with RTL %s!\n",
-           DPxPTR(Img->ImageStart), R->RTLName.c_str());
+      // Ensure that we do not use any unused images associated with this RTL.
+      if (!R->UsedImages.contains(Img))
         continue;
-      }
-
-      DP("Image " DPxMOD " is compatible with RTL " DPxMOD "!\n",
-         DPxPTR(Img->ImageStart), DPxPTR(R->LibraryHandler.get()));
 
       FoundRTL = R;