Expose "noduplicate" attribute as a property for intrinsics.

The "noduplicate" function attribute exists to prevent certain optimizations
from duplicating calls to the function. This is important on platforms where
certain function call duplications are unsafe (for example execution barriers
for CUDA and OpenCL).

This patch makes it possible to specify intrinsics as "noduplicate" and
translates that to the appropriate function attribute.

llvm-svn: 204200

3 files changed, 17 insertions, 1 deletions

diff --git a/llvm/utils/TableGen/CodeGenIntrinsics.h b/llvm/utils/TableGen/CodeGenIntrinsics.h
index edbb18b..06daa97 100644
--- a/llvm/utils/TableGen/CodeGenIntrinsics.h
+++ b/llvm/utils/TableGen/CodeGenIntrinsics.h
@@ -73,6 +73,9 @@ namespace llvm {
     /// canThrow - True if the intrinsic can throw.
     bool canThrow;
 
+    /// isNoDuplicate - True if the intrinsic is marked as noduplicate.
+    bool isNoDuplicate;
+
     /// isNoReturn - True if the intrinsic is no-return.
     bool isNoReturn;
 
diff --git a/llvm/utils/TableGen/CodeGenTarget.cpp b/llvm/utils/TableGen/CodeGenTarget.cpp
index 1f47675..884af4c 100644
--- a/llvm/utils/TableGen/CodeGenTarget.cpp
+++ b/llvm/utils/TableGen/CodeGenTarget.cpp
@@ -446,6 +446,7 @@ CodeGenIntrinsic::CodeGenIntrinsic(Record *R) {
   isCommutative = false;
   canThrow = false;
   isNoReturn = false;
+  isNoDuplicate = false;
 
   if (DefName.size() <= 4 ||
       std::string(DefName.begin(), DefName.begin() + 4) != "int_")
@@ -570,6 +571,8 @@ CodeGenIntrinsic::CodeGenIntrinsic(Record *R) {
       isCommutative = true;
     else if (Property->getName() == "Throws")
       canThrow = true;
+    else if (Property->getName() == "IntrNoDuplicate")
+      isNoDuplicate = true;
     else if (Property->getName() == "IntrNoReturn")
       isNoReturn = true;
     else if (Property->isSubClassOf("NoCapture")) {
diff --git a/llvm/utils/TableGen/IntrinsicEmitter.cpp b/llvm/utils/TableGen/IntrinsicEmitter.cpp
index cf6934c..1b28128 100644
--- a/llvm/utils/TableGen/IntrinsicEmitter.cpp
+++ b/llvm/utils/TableGen/IntrinsicEmitter.cpp
@@ -502,6 +502,9 @@ struct AttributeComparator {
     if (L->canThrow != R->canThrow)
       return R->canThrow;
 
+    if (L->isNoDuplicate != R->isNoDuplicate)
+      return R->isNoDuplicate;
+
     if (L->isNoReturn != R->isNoReturn)
       return R->isNoReturn;
 
@@ -616,7 +619,8 @@ EmitAttributes(const std::vector<CodeGenIntrinsic> &Ints, raw_ostream &OS) {
 
     ModRefKind modRef = getModRefKind(intrinsic);
 
-    if (!intrinsic.canThrow || modRef || intrinsic.isNoReturn) {
+    if (!intrinsic.canThrow || modRef || intrinsic.isNoReturn ||
+        intrinsic.isNoDuplicate) {
       OS << "      const Attribute::AttrKind Atts[] = {";
       bool addComma = false;
       if (!intrinsic.canThrow) {
@@ -629,6 +633,12 @@ EmitAttributes(const std::vector<CodeGenIntrinsic> &Ints, raw_ostream &OS) {
         OS << "Attribute::NoReturn";
         addComma = true;
       }
+      if (intrinsic.isNoDuplicate) {
+        if (addComma)
+          OS << ",";
+        OS << "Attribute::NoDuplicate";
+        addComma = true;
+      }
 
       switch (modRef) {
       case MRK_none: break;