GPGPU: Bail out gracefully in case of invalid IR

Instead of aborting, we now bail out gracefully in case the kernel IR we
generate is invalid. This can currently happen in case the SCoP stores
pointer values, which we model as arrays, as data values into other arrays. In
this case, the original pointer value is not available on the device and can
consequently not be stored. As detecting this ahead of time is not so easy, we
detect these situations after the invalid IR has been generated and bail out.

llvm-svn: 281193

1 files changed, 13 insertions, 4 deletions

diff --git a/polly/lib/CodeGen/PPCGCodeGeneration.cpp b/polly/lib/CodeGen/PPCGCodeGeneration.cpp
index 66ffa730acc..783d256a32c 100644
--- a/polly/lib/CodeGen/PPCGCodeGeneration.cpp
+++ b/polly/lib/CodeGen/PPCGCodeGeneration.cpp
@@ -152,6 +152,12 @@ public:
   /// Finalize the generated scop.
   virtual void finalize();
 
+  /// Track if the full build process was successful.
+  ///
+  /// This value is set to false, if throughout the build process an error
+  /// occurred which prevents us from generating valid GPU code.
+  bool BuildSuccessful = true;
+
 private:
   /// A vector of array base pointers for which a new ScopArrayInfo was created.
   ///
@@ -1409,10 +1415,10 @@ std::string GPUNodeBuilder::createKernelASM() {
 }
 
 std::string GPUNodeBuilder::finalizeKernelFunction() {
-  // Verify module.
-  llvm::legacy::PassManager Passes;
-  Passes.add(createVerifierPass());
-  Passes.run(*GPUModule);
+  if (verifyModule(*GPUModule)) {
+    BuildSuccessful = false;
+    return "";
+  }
 
   if (DumpKernelIR)
     outs() << *GPUModule << "\n";
@@ -2139,6 +2145,9 @@ public:
     NodeBuilder.initializeAfterRTH();
     NodeBuilder.create(Root);
     NodeBuilder.finalize();
+
+    if (!NodeBuilder.BuildSuccessful)
+      SplitBlock->getTerminator()->setOperand(0, Builder.getFalse());
   }
 
   bool runOnScop(Scop &CurrentScop) override {