[coroutines] Part 3 of N: Adding Boilerplate for Coroutine Passes

This adds boilerplate code for all coroutine passes,
the passes are no-ops for now.
Also, a small test has been added to verify that passes execute in
the expected order or not at all if coroutine support is disabled.

Patch by Gor Nishanov!

Differential Revision: https://reviews.llvm.org/D22847

llvm-svn: 277033

10 files changed, 307 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/CMakeLists.txt b/llvm/lib/Transforms/CMakeLists.txt
index 2bb6e905909..67bdeb27212 100644
--- a/llvm/lib/Transforms/CMakeLists.txt
+++ b/llvm/lib/Transforms/CMakeLists.txt
@@ -6,3 +6,4 @@ add_subdirectory(IPO)
 add_subdirectory(Vectorize)
 add_subdirectory(Hello)
 add_subdirectory(ObjCARC)
+add_subdirectory(Coroutines)
diff --git a/llvm/lib/Transforms/Coroutines/CMakeLists.txt b/llvm/lib/Transforms/Coroutines/CMakeLists.txt
new file mode 100644
index 00000000000..0e9e9e43e8e
--- /dev/null
+++ b/llvm/lib/Transforms/Coroutines/CMakeLists.txt
@@ -0,0 +1,8 @@
+add_llvm_library(LLVMCoroutines
+  Coroutines.cpp
+  CoroCleanup.cpp
+  CoroEarly.cpp
+  CoroElide.cpp
+  CoroSplit.cpp
+  )
+
diff --git a/llvm/lib/Transforms/Coroutines/CoroCleanup.cpp b/llvm/lib/Transforms/Coroutines/CoroCleanup.cpp
new file mode 100644
index 00000000000..078a09f6e1f
--- /dev/null
+++ b/llvm/lib/Transforms/Coroutines/CoroCleanup.cpp
@@ -0,0 +1,42 @@
+//===- CoroCleanup.cpp - Coroutine Cleanup Pass ---------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This pass lowers all remaining coroutine intrinsics.
+//===----------------------------------------------------------------------===//
+
+#include "CoroInternal.h"
+#include "llvm/Pass.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "coro-cleanup"
+
+//===----------------------------------------------------------------------===//
+//                              Top Level Driver
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+struct CoroCleanup : FunctionPass {
+  static char ID; // Pass identification, replacement for typeid
+
+  CoroCleanup() : FunctionPass(ID) {}
+
+  bool runOnFunction(Function &F) override { return false; }
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesAll();
+  }
+};
+
+}
+
+char CoroCleanup::ID = 0;
+INITIALIZE_PASS(CoroCleanup, "coro-cleanup",
+                "Lower all coroutine related intrinsics", false, false)
+
+Pass *llvm::createCoroCleanupPass() { return new CoroCleanup(); }
diff --git a/llvm/lib/Transforms/Coroutines/CoroEarly.cpp b/llvm/lib/Transforms/Coroutines/CoroEarly.cpp
new file mode 100644
index 00000000000..baedb2422d0
--- /dev/null
+++ b/llvm/lib/Transforms/Coroutines/CoroEarly.cpp
@@ -0,0 +1,43 @@
+//===- CoroEarly.cpp - Coroutine Early Function Pass ----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This pass lowers coroutine intrinsics that hide the details of the exact
+// calling convention for coroutine resume and destroy functions and details of
+// the structure of the coroutine frame.
+//===----------------------------------------------------------------------===//
+
+#include "CoroInternal.h"
+#include "llvm/Pass.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "coro-early"
+
+//===----------------------------------------------------------------------===//
+//                              Top Level Driver
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+struct CoroEarly : public FunctionPass {
+  static char ID; // Pass identification, replacement for typeid
+  CoroEarly() : FunctionPass(ID) {}
+
+  bool runOnFunction(Function &F) override { return false; }
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesAll();
+  }
+};
+
+}
+
+char CoroEarly::ID = 0;
+INITIALIZE_PASS(CoroEarly, "coro-early", "Lower early coroutine intrinsics",
+                false, false)
+
+Pass *llvm::createCoroEarlyPass() { return new CoroEarly(); }
diff --git a/llvm/lib/Transforms/Coroutines/CoroElide.cpp b/llvm/lib/Transforms/Coroutines/CoroElide.cpp
new file mode 100644
index 00000000000..b21380ca008
--- /dev/null
+++ b/llvm/lib/Transforms/Coroutines/CoroElide.cpp
@@ -0,0 +1,49 @@
+//===- CoroElide.cpp - Coroutine Frame Allocation Elision Pass ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This pass replaces dynamic allocation of coroutine frame with alloca and
+// replaces calls to llvm.coro.resume and llvm.coro.destroy with direct calls
+// to coroutine sub-functions.
+//===----------------------------------------------------------------------===//
+
+#include "CoroInternal.h"
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Pass.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "coro-elide"
+
+//===----------------------------------------------------------------------===//
+//                              Top Level Driver
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+struct CoroElide : FunctionPass {
+  static char ID;
+  CoroElide() : FunctionPass(ID) {}
+  bool runOnFunction(Function &F) override { return false; }
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesAll();
+  }
+};
+
+}
+
+char CoroElide::ID = 0;
+INITIALIZE_PASS_BEGIN(
+    CoroElide, "coro-elide",
+    "Coroutine frame allocation elision and indirect calls replacement", false,
+    false)
+INITIALIZE_PASS_END(
+    CoroElide, "coro-elide",
+    "Coroutine frame allocation elision and indirect calls replacement", false,
+    false)
+
+Pass *llvm::createCoroElidePass() { return new CoroElide(); }
diff --git a/llvm/lib/Transforms/Coroutines/CoroInternal.h b/llvm/lib/Transforms/Coroutines/CoroInternal.h
new file mode 100644
index 00000000000..97620921fc9
--- /dev/null
+++ b/llvm/lib/Transforms/Coroutines/CoroInternal.h
@@ -0,0 +1,28 @@
+//===- CoroInternal.h - Internal Coroutine interfaces ---------*- C++ -*---===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Common definitions/declarations used internally by coroutine lowering passes.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TRANSFORMS_COROUTINES_COROINTERNAL_H
+#define LLVM_LIB_TRANSFORMS_COROUTINES_COROINTERNAL_H
+
+#include "llvm/Transforms/Coroutines.h"
+
+namespace llvm {
+
+class PassRegistry;
+
+void initializeCoroEarlyPass(PassRegistry &);
+void initializeCoroSplitPass(PassRegistry &);
+void initializeCoroElidePass(PassRegistry &);
+void initializeCoroCleanupPass(PassRegistry &);
+
+}
+
+#endif
diff --git a/llvm/lib/Transforms/Coroutines/CoroSplit.cpp b/llvm/lib/Transforms/Coroutines/CoroSplit.cpp
new file mode 100644
index 00000000000..70d5aa92f20
--- /dev/null
+++ b/llvm/lib/Transforms/Coroutines/CoroSplit.cpp
@@ -0,0 +1,45 @@
+//===- CoroSplit.cpp - Converts a coroutine into a state machine ----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This pass builds the coroutine frame and outlines resume and destroy parts
+// of the coroutine into separate functions.
+//===----------------------------------------------------------------------===//
+
+#include "CoroInternal.h"
+#include "llvm/Analysis/CallGraphSCCPass.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "coro-split"
+
+//===----------------------------------------------------------------------===//
+//                              Top Level Driver
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+struct CoroSplit : public CallGraphSCCPass {
+  static char ID; // Pass identification, replacement for typeid
+  CoroSplit() : CallGraphSCCPass(ID) {}
+
+  bool runOnSCC(CallGraphSCC &SCC) override { return false; }
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesAll();
+    CallGraphSCCPass::getAnalysisUsage(AU);
+  }
+};
+
+}
+
+char CoroSplit::ID = 0;
+INITIALIZE_PASS(
+    CoroSplit, "coro-split",
+    "Split coroutine into a set of functions driving its state machine", false,
+    false)
+
+Pass *llvm::createCoroSplitPass() { return new CoroSplit(); }
diff --git a/llvm/lib/Transforms/Coroutines/Coroutines.cpp b/llvm/lib/Transforms/Coroutines/Coroutines.cpp
new file mode 100644
index 00000000000..70b3d41a58b
--- /dev/null
+++ b/llvm/lib/Transforms/Coroutines/Coroutines.cpp
@@ -0,0 +1,68 @@
+//===-- Coroutines.cpp ----------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This file implements the common infrastructure for Coroutine Passes.
+//===----------------------------------------------------------------------===//
+
+#include "CoroInternal.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/InitializePasses.h"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+
+using namespace llvm;
+
+void llvm::initializeCoroutines(PassRegistry &Registry) {
+  initializeCoroEarlyPass(Registry);
+  initializeCoroSplitPass(Registry);
+  initializeCoroElidePass(Registry);
+  initializeCoroCleanupPass(Registry);
+}
+
+static void addCoroutineOpt0Passes(const PassManagerBuilder &Builder,
+                                   legacy::PassManagerBase &PM) {
+  PM.add(createCoroSplitPass());
+  PM.add(createCoroElidePass());
+
+  PM.add(createBarrierNoopPass());
+  PM.add(createCoroCleanupPass());
+}
+
+static void addCoroutineEarlyPasses(const PassManagerBuilder &Builder,
+                                    legacy::PassManagerBase &PM) {
+  PM.add(createCoroEarlyPass());
+}
+
+static void addCoroutineScalarOptimizerPasses(const PassManagerBuilder &Builder,
+                                              legacy::PassManagerBase &PM) {
+  PM.add(createCoroElidePass());
+}
+
+static void addCoroutineSCCPasses(const PassManagerBuilder &Builder,
+                                  legacy::PassManagerBase &PM) {
+  PM.add(createCoroSplitPass());
+}
+
+static void addCoroutineOptimizerLastPasses(const PassManagerBuilder &Builder,
+                                            legacy::PassManagerBase &PM) {
+  PM.add(createCoroCleanupPass());
+}
+
+void llvm::addCoroutinePassesToExtensionPoints(PassManagerBuilder &Builder) {
+  Builder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
+                       addCoroutineEarlyPasses);
+  Builder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
+                       addCoroutineOpt0Passes);
+  Builder.addExtension(PassManagerBuilder::EP_CGSCCOptimizerLate,
+                       addCoroutineSCCPasses);
+  Builder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
+                       addCoroutineScalarOptimizerPasses);
+  Builder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                       addCoroutineOptimizerLastPasses);
+}
diff --git a/llvm/lib/Transforms/Coroutines/LLVMBuild.txt b/llvm/lib/Transforms/Coroutines/LLVMBuild.txt
new file mode 100644
index 00000000000..41dc4b031a4
--- /dev/null
+++ b/llvm/lib/Transforms/Coroutines/LLVMBuild.txt
@@ -0,0 +1,22 @@
+;===- ./lib/Transforms/Coroutines/LLVMBuild.txt ----------------*- Conf -*--===;
+;
+;                     The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Library
+name = Coroutines
+parent = Transforms
+required_libraries = Analysis Core IPO Scalar Support TransformUtils
diff --git a/llvm/lib/Transforms/LLVMBuild.txt b/llvm/lib/Transforms/LLVMBuild.txt
index 15e9fba0a76..95482ad2022 100644
--- a/llvm/lib/Transforms/LLVMBuild.txt
+++ b/llvm/lib/Transforms/LLVMBuild.txt
@@ -16,7 +16,7 @@
 ;===------------------------------------------------------------------------===;
 
 [common]
-subdirectories = IPO InstCombine Instrumentation Scalar Utils Vectorize ObjCARC
+subdirectories = Coroutines IPO InstCombine Instrumentation Scalar Utils Vectorize ObjCARC
 
 [component_0]
 type = Group