From dca42389f7415a003e06aa48861202eee31dce3f Mon Sep 17 00:00:00 2001
From: Eli Friedman <efriedma@codeaurora.org>
Date: Thu, 1 Jun 2017 21:22:26 +0000
Subject: [PATCH] Add opt-bisect support for region passes.

This is necessary to get opt-bisect working with polly.

Differential Revision: https://reviews.llvm.org/D33751



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304476 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Analysis/RegionPass.h |  5 +++++
 lib/Analysis/RegionPass.cpp        | 16 ++++++++++++++++
 lib/IR/OptBisect.cpp               | 15 ++++++++++++---
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/include/llvm/Analysis/RegionPass.h b/include/llvm/Analysis/RegionPass.h
index b5f38139abf..515b362e540 100644
--- a/include/llvm/Analysis/RegionPass.h
+++ b/include/llvm/Analysis/RegionPass.h
@@ -78,6 +78,11 @@ public:
     return PMT_RegionPassManager;
   }
   //@}
+
+protected:
+  /// Optional passes call this function to check whether the pass should be
+  /// skipped. This is the case when optimization bisect is over the limit.
+  bool skipRegion(Region &R) const;
 };
 
 /// @brief The pass manager to schedule RegionPasses.
diff --git a/lib/Analysis/RegionPass.cpp b/lib/Analysis/RegionPass.cpp
index 82107cb1802..b38e6225c84 100644
--- a/lib/Analysis/RegionPass.cpp
+++ b/lib/Analysis/RegionPass.cpp
@@ -15,6 +15,7 @@
 //===----------------------------------------------------------------------===//
 #include "llvm/Analysis/RegionPass.h"
 #include "llvm/Analysis/RegionIterator.h"
+#include "llvm/IR/OptBisect.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/raw_ostream.h"
@@ -280,3 +281,18 @@ Pass *RegionPass::createPrinterPass(raw_ostream &O,
                                   const std::string &Banner) const {
   return new PrintRegionPass(Banner, O);
 }
+
+bool RegionPass::skipRegion(Region &R) const {
+  Function &F = *R.getEntry()->getParent();
+  if (!F.getContext().getOptBisect().shouldRunPass(this, R))
+    return true;
+
+  if (F.hasFnAttribute(Attribute::OptimizeNone)) {
+    // Report this only once per function.
+    if (R.getEntry() == &F.getEntryBlock())
+      DEBUG(dbgs() << "Skipping pass '" << getPassName()
+            << "' on function " << F.getName() << "\n");
+    return true;
+  }
+  return false;
+}
diff --git a/lib/IR/OptBisect.cpp b/lib/IR/OptBisect.cpp
index b670c817569..a03a6fb6223 100644
--- a/lib/IR/OptBisect.cpp
+++ b/lib/IR/OptBisect.cpp
@@ -16,6 +16,7 @@
 #include "llvm/Analysis/CallGraphSCCPass.h"
 #include "llvm/Analysis/LazyCallGraph.h"
 #include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/RegionInfo.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/OptBisect.h"
 #include "llvm/Pass.h"
@@ -53,13 +54,20 @@ static std::string getDescription(const BasicBlock &BB) {
 }
 
 static std::string getDescription(const Loop &L) {
-  // FIXME: I'd like to be able to provide a better description here, but
-  //        calling L->getHeader() would introduce a new dependency on the
-  //        LLVMCore library.
+  // FIXME: Move into LoopInfo so we can get a better description
+  // (and avoid a circular dependency between IR and Analysis).
   return "loop";
 }
 
+static std::string getDescription(const Region &R) {
+  // FIXME: Move into RegionInfo so we can get a better description
+  // (and avoid a circular dependency between IR and Analysis).
+  return "region";
+}
+
 static std::string getDescription(const CallGraphSCC &SCC) {
+  // FIXME: Move into CallGraphSCCPass to avoid circular dependency between
+  // IR and Analysis.
   std::string Desc = "SCC (";
   bool First = true;
   for (CallGraphNode *CGN : SCC) {
@@ -83,6 +91,7 @@ template bool OptBisect::shouldRunPass(const Pass *, const Function &);
 template bool OptBisect::shouldRunPass(const Pass *, const BasicBlock &);
 template bool OptBisect::shouldRunPass(const Pass *, const Loop &);
 template bool OptBisect::shouldRunPass(const Pass *, const CallGraphSCC &);
+template bool OptBisect::shouldRunPass(const Pass *, const Region &);
 
 template <class UnitT>
 bool OptBisect::shouldRunPass(const Pass *P, const UnitT &U) {