[irgen-prepare] Move SILCleanup to ./lib/SILOptimizer/Mandatory and rename it to IRGenPrepare.

I am going to be adding logic here to enable #1550 to be completed.
The rename makes sense due to precedent from LLVM's codegen prepare and also
since I am going to be expanding what the pass is doing beyond just "cleaning
up". It is really a grab bag pass for performing simple transformations that we
do not want to pollute IRGen's logic with.

#15502

rdar://39335800

Author: gottesmm

include/swift/SILOptimizer/PassManager/Passes.def

@@ -232,8 +232,8 @@ PASS(TempRValueOpt, "temp-rvalue-opt",
      "Remove short-lived immutable temporary copies")
 PASS(SideEffectsDumper, "side-effects-dump",
      "Print Side-Effect Information for all Functions")
-PASS(SILCleanup, "cleanup",
-     "SIL Cleanup Preparation for IRGen")
+PASS(IRGenPrepare, "irgen-prepare",
+     "Cleanup SIL in preparation for IRGen")
 PASS(SILCombine, "sil-combine",
      "Combine SIL Instructions via Peephole Optimization")
 PASS(SILDebugInfoGenerator, "sil-debuginfo-gen",

lib/SILOptimizer/Mandatory/CMakeLists.txt

@@ -2,6 +2,7 @@ set(MANDATORY_SOURCES
   Mandatory/AccessEnforcementSelection.cpp
   Mandatory/AccessMarkerElimination.cpp
   Mandatory/AddressLowering.cpp
+  Mandatory/ConstantPropagation.cpp
   Mandatory/DefiniteInitialization.cpp
   Mandatory/DIMemoryUseCollector.cpp
   Mandatory/DIMemoryUseCollectorOwnership.cpp
@@ -10,8 +11,8 @@ set(MANDATORY_SOURCES
   Mandatory/DiagnoseStaticExclusivity.cpp
   Mandatory/DiagnoseUnreachable.cpp
   Mandatory/GuaranteedARCOpts.cpp
+  Mandatory/IRGenPrepare.cpp
   Mandatory/MandatoryInlining.cpp
   Mandatory/PredictableMemOpt.cpp
-  Mandatory/ConstantPropagation.cpp
   Mandatory/SemanticARCOpts.cpp
   PARENT_SCOPE)

lib/SILOptimizer/Transforms/SILCleanup.cpp renamed to lib/SILOptimizer/Mandatory/IRGenPrepare.cpp

@@ -1,8 +1,8 @@
-//===--- SILCleanup.cpp - Removes diagnostics instructions ----------------===//
+//===--- IRGenPrepare.cpp -------------------------------------------------===//
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -13,9 +13,6 @@
 // Cleanup SIL to make it suitable for IRGen. Specifically, removes the calls to
 // Builtin.staticReport(), which are not needed post SIL.
 //
-// FIXME: This pass is mandatory so should probably be in
-// SILOptimizer/Mandatory.
-//
 //===----------------------------------------------------------------------===//
 
 #include "swift/SILOptimizer/PassManager/Passes.h"
@@ -50,7 +47,7 @@ static void cleanFunction(SILFunction &Fn) {
 }
 
 namespace {
-class SILCleanup : public swift::SILFunctionTransform {
+class IRGenPrepare : public swift::SILFunctionTransform {
 
   /// The entry point to the transformation.
   void run() override {
@@ -62,6 +59,6 @@ class SILCleanup : public swift::SILFunctionTransform {
 } // end anonymous namespace
 
 
-SILTransform *swift::createSILCleanup() {
-  return new SILCleanup();
+SILTransform *swift::createIRGenPrepare() {
+  return new IRGenPrepare();
 }

lib/SILOptimizer/PassManager/PassPipeline.cpp

@@ -456,7 +456,7 @@ SILPassPipelinePlan
 SILPassPipelinePlan::getLoweringPassPipeline() {
   SILPassPipelinePlan P;
   P.startPipeline("Address Lowering");
-  P.addSILCleanup();
+  P.addIRGenPrepare();
   P.addAddressLowering();
 
   return P;

lib/SILOptimizer/Transforms/CMakeLists.txt

@@ -23,7 +23,6 @@ set(TRANSFORMS_SOURCES
   Transforms/RedundantOverflowCheckRemoval.cpp
   Transforms/ReleaseDevirtualizer.cpp
   Transforms/RemovePin.cpp
-  Transforms/SILCleanup.cpp
   Transforms/SILCodeMotion.cpp
   Transforms/SILLowerAggregateInstrs.cpp
   Transforms/SILMem2Reg.cpp

utils/pass-pipeline/src/passes.py

@@ -40,7 +40,7 @@
 PerfInliner = Pass('PerfInliner')
 PerformanceConstantPropagation = Pass('PerformanceConstantPropagation')
 PredictableMemoryOptimizations = Pass('PredictableMemoryOptimizations')
-SILCleanup = Pass('SILCleanup')
+IRGenPrepare = Pass('IRGenPrepare')
 SILCombine = Pass('SILCombine')
 SILLinker = Pass('SILLinker')
 SROA = Pass('SROA')
@@ -89,7 +89,7 @@
     PerfInliner,
     PerformanceConstantPropagation,
     PredictableMemoryOptimizations,
-    SILCleanup,
+    IRGenPrepare,
     SILCombine,
     SILLinker,
     SROA,