Moving ManagedMemoryRewritePass when hybrid option is selected

[chelini]

Summary

Compiling with polly-target=hybrid was causing Polly to occur two times in the pipeline. The reason was how the ManagedMemoryRewritePass was registered in the pass manager. Being ManagedMemoryRewritePass a Modulepass was forcing all previous passes to get recomputed. This commit avoids Polly to appear two times in the pipeline registering the ManagedMemoryRewritePass later in the pass manager.

[Meinersbur]

LGTM

[Meinersbur]

Do you need help with landing the patch?

[chelini]

In D59263#1441600, @Meinersbur wrote:

Do you need help with landing the patch?

Hi Michael,
Yes, could you please land it on my behalf?
Thanks.

[Meinersbur]

Done. Thanks for the patch!

lib/Support/RegisterPasses.cpp

void registerPollyPasses(llvm::legacy::PassManagerBase &PM) {
 
   if (FullyIndexedStaticExpansion)
     PM.add(polly::createMaximalStaticExpansionPass());
 
   if (EnablePruneUnprofitable)
     PM.add(polly::createPruneUnprofitablePass());
 
 #ifdef GPU_CODEGEN
-  if (Target == TARGET_HYBRID) {
+  if (Target == TARGET_HYBRID)
     PM.add(
         polly::createPPCGCodeGenerationPass(GPUArchChoice, GPURuntimeChoice));
-    PM.add(polly::createManagedMemoryRewritePassPass(GPUArchChoice,
-                                                     GPURuntimeChoice));
-  }
 #endif
   if (Target == TARGET_CPU || Target == TARGET_HYBRID)
     switch (Optimizer) {
     case OPTIMIZER_NONE:
       break; /* Do nothing */
 
     case OPTIMIZER_ISL:
       PM.add(polly::createIslScheduleOptimizerPass());

 #ifdef GPU_CODEGEN
   else {
     PM.add(
         polly::createPPCGCodeGenerationPass(GPUArchChoice, GPURuntimeChoice));
     PM.add(polly::createManagedMemoryRewritePassPass());
   }
 #endif
 
+#ifdef GPU_CODEGEN
+  if (Target == TARGET_HYBRID)
+    PM.add(polly::createManagedMemoryRewritePassPass(GPUArchChoice,
+                                                     GPURuntimeChoice));
+#endif
+
   // FIXME: This dummy ModulePass keeps some programs from miscompiling,
   // probably some not correctly preserved analyses. It acts as a barrier to
   // force all analysis results to be recomputed.
   PM.add(createBarrierNoopPass());
 
   if (DumpAfter)
     PM.add(polly::createDumpModulePass("-after", true));
   for (auto &Filename : DumpAfterFile)