[Attributor] Deduce "willreturn" function attribute

Summary:
Deduce the "willreturn" attribute for functions.

For now, intrinsics are not willreturn. More annotation will be done in another patch.

Reviewers: jdoerfert

Subscribers: jvesely, nhaehnle, nicholas, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63046

llvm-svn: 366335

3 files changed, 18 insertions, 2 deletions

diff --git a/llvm/utils/TableGen/CodeGenIntrinsics.h b/llvm/utils/TableGen/CodeGenIntrinsics.h
index 9dcd136463c..7b74bb07d6e 100644
--- a/llvm/utils/TableGen/CodeGenIntrinsics.h
+++ b/llvm/utils/TableGen/CodeGenIntrinsics.h
@@ -123,6 +123,9 @@ struct CodeGenIntrinsic {
   /// True if the intrinsic is no-return.
   bool isNoReturn;
 
+  /// True if the intrinsic is will-return.
+  bool isWillReturn;
+
   /// True if the intrinsic is cold.
   bool isCold;
 
diff --git a/llvm/utils/TableGen/CodeGenTarget.cpp b/llvm/utils/TableGen/CodeGenTarget.cpp
index 702317283f9..b65e1b6af79 100644
--- a/llvm/utils/TableGen/CodeGenTarget.cpp
+++ b/llvm/utils/TableGen/CodeGenTarget.cpp
@@ -557,6 +557,7 @@ CodeGenIntrinsic::CodeGenIntrinsic(Record *R) {
   isCommutative = false;
   canThrow = false;
   isNoReturn = false;
+  isWillReturn = false;
   isCold = false;
   isNoDuplicate = false;
   isConvergent = false;
@@ -721,6 +722,8 @@ CodeGenIntrinsic::CodeGenIntrinsic(Record *R) {
       isConvergent = true;
     else if (Property->getName() == "IntrNoReturn")
       isNoReturn = true;
+    else if (Property->getName() == "IntrWillReturn")
+      isWillReturn = true;
     else if (Property->getName() == "IntrCold")
       isCold = true;
     else if (Property->getName() == "IntrSpeculatable")
diff --git a/llvm/utils/TableGen/IntrinsicEmitter.cpp b/llvm/utils/TableGen/IntrinsicEmitter.cpp
index 6bcdc3d777a..979af98f676 100644
--- a/llvm/utils/TableGen/IntrinsicEmitter.cpp
+++ b/llvm/utils/TableGen/IntrinsicEmitter.cpp
@@ -545,6 +545,9 @@ struct AttributeComparator {
     if (L->isNoReturn != R->isNoReturn)
       return R->isNoReturn;
 
+    if (L->isWillReturn != R->isWillReturn)
+      return R->isWillReturn;
+
     if (L->isCold != R->isCold)
       return R->isCold;
 
@@ -686,8 +689,9 @@ void IntrinsicEmitter::EmitAttributes(const CodeGenIntrinsicTable &Ints,
 
     if (!intrinsic.canThrow ||
         (intrinsic.ModRef != CodeGenIntrinsic::ReadWriteMem && !intrinsic.hasSideEffects) ||
-        intrinsic.isNoReturn || intrinsic.isCold || intrinsic.isNoDuplicate ||
-        intrinsic.isConvergent || intrinsic.isSpeculatable) {
+        intrinsic.isNoReturn || intrinsic.isWillReturn || intrinsic.isCold ||
+        intrinsic.isNoDuplicate || intrinsic.isConvergent ||
+        intrinsic.isSpeculatable) {
       OS << "      const Attribute::AttrKind Atts[] = {";
       bool addComma = false;
       if (!intrinsic.canThrow) {
@@ -700,6 +704,12 @@ void IntrinsicEmitter::EmitAttributes(const CodeGenIntrinsicTable &Ints,
         OS << "Attribute::NoReturn";
         addComma = true;
       }
+      if (intrinsic.isWillReturn) {
+        if (addComma)
+          OS << ",";
+        OS << "Attribute::WillReturn";
+        addComma = true;
+      }
       if (intrinsic.isCold) {
         if (addComma)
           OS << ",";