Cache the IRGenModule even between SIL passes

Author: kubamracek

include/swift/SILOptimizer/PassManager/PassManager.h

@@ -102,6 +102,8 @@ class SwiftPassInvocation {
   SwiftPassInvocation(SILPassManager *passManager) :
     passManager(passManager) {}
 
+  ~SwiftPassInvocation();
+
   SILPassManager *getPassManager() const { return passManager; }
 
   SILTransform *getTransform() const { return transform; }

lib/SILOptimizer/PassManager/PassManager.cpp

@@ -1392,9 +1392,7 @@ irgen::IRGenModule *SwiftPassInvocation::getIRGenModule() {
 
     irgen = new irgen::IRGenerator(*irgenOpts, *module);
     auto targetMachine = irgen->createTargetMachine();
-    if (!targetMachine)
-      return nullptr;
-
+    assert(targetMachine && "failed to create target");
     irgenModule = new irgen::IRGenModule(*irgen, std::move(targetMachine));
   }
   return irgenModule;
@@ -1410,14 +1408,6 @@ void SwiftPassInvocation::endPass() {
     delete ssaUpdater;
     ssaUpdater = nullptr;
   }
-  if (irgenModule) {
-    delete irgenModule;
-    irgenModule = nullptr;
-  }
-  if (irgen) {
-    delete irgen;
-    irgen = nullptr;
-  }
 }
 
 void SwiftPassInvocation::beginTransformFunction(SILFunction *function) {
@@ -1438,6 +1428,17 @@ void SwiftPassInvocation::endTransformFunction() {
   assert(numNodeSetsAllocated == 0 && "Not all NodeSets deallocated");
 }
 
+SwiftPassInvocation::~SwiftPassInvocation() {
+  if (irgenModule) {
+    delete irgenModule;
+    irgenModule = nullptr;
+  }
+  if (irgen) {
+    delete irgen;
+    irgen = nullptr;
+  }
+}
+
 //===----------------------------------------------------------------------===//
 //                            Swift Bridging
 //===----------------------------------------------------------------------===//