commit b19b57ea60da58d81c4af03a7ef2a1dd6a640267
author Matt Arsenault <Matthew.Arsenault@amd.com> Fri Apr 28 20:25:27 2017 +0000
committer Matt Arsenault <Matthew.Arsenault@amd.com> Fri Apr 28 20:25:27 2017 +0000
tree 316220d5be2377b1456f2263960e67b6b11a5ed2
parent 744c215e2958c13854c1d730a323132ce2dc9c57

Add speculatable function attribute

This attribute tells the optimizer that the function may be speculated.

Patch by Tom Stellard

llvm-svn: 301680

llvm/utils/TableGen/CodeGenIntrinsics.h

diff --git a/llvm/utils/TableGen/CodeGenIntrinsics.h b/llvm/utils/TableGen/CodeGenIntrinsics.h
index 6df0e6a..d126f27 100644
--- a/llvm/utils/TableGen/CodeGenIntrinsics.h
+++ b/llvm/utils/TableGen/CodeGenIntrinsics.h
@@ -123,6 +123,9 @@
   /// True if the intrinsic is marked as convergent.
   bool isConvergent;
 
+  // True if the intrinsic is marked as speculatable.
+  bool isSpeculatable;
+
   enum ArgAttribute { NoCapture, Returned, ReadOnly, WriteOnly, ReadNone };
   std::vector<std::pair<unsigned, ArgAttribute>> ArgumentAttributes;
 

llvm/utils/TableGen/CodeGenTarget.cpp

diff --git a/llvm/utils/TableGen/CodeGenTarget.cpp b/llvm/utils/TableGen/CodeGenTarget.cpp
index 03c58ac..aad9005 100644
--- a/llvm/utils/TableGen/CodeGenTarget.cpp
+++ b/llvm/utils/TableGen/CodeGenTarget.cpp
@@ -515,6 +515,7 @@
   isNoReturn = false;
   isNoDuplicate = false;
   isConvergent = false;
+  isSpeculatable = false;
 
   if (DefName.size() <= 4 ||
       std::string(DefName.begin(), DefName.begin() + 4) != "int_")
@@ -653,6 +654,8 @@
       isConvergent = true;
     else if (Property->getName() == "IntrNoReturn")
       isNoReturn = true;
+    else if (Property->getName() == "IntrSpeculatable")
+      isSpeculatable = true;
     else if (Property->isSubClassOf("NoCapture")) {
       unsigned ArgNo = Property->getValueAsInt("ArgNo");
       ArgumentAttributes.push_back(std::make_pair(ArgNo, NoCapture));

llvm/utils/TableGen/IntrinsicEmitter.cpp

diff --git a/llvm/utils/TableGen/IntrinsicEmitter.cpp b/llvm/utils/TableGen/IntrinsicEmitter.cpp
index e979b94..72f2dce 100644
--- a/llvm/utils/TableGen/IntrinsicEmitter.cpp
+++ b/llvm/utils/TableGen/IntrinsicEmitter.cpp
@@ -476,6 +476,9 @@
     if (L->isConvergent != R->isConvergent)
       return R->isConvergent;
 
+    if (L->isSpeculatable != R->isSpeculatable)
+      return R->isSpeculatable;
+
     // Try to order by readonly/readnone attribute.
     CodeGenIntrinsic::ModRefBehavior LK = L->ModRef;
     CodeGenIntrinsic::ModRefBehavior RK = R->ModRef;
@@ -600,7 +603,7 @@
     if (!intrinsic.canThrow ||
         intrinsic.ModRef != CodeGenIntrinsic::ReadWriteMem ||
         intrinsic.isNoReturn || intrinsic.isNoDuplicate ||
-        intrinsic.isConvergent) {
+        intrinsic.isConvergent || intrinsic.isSpeculatable) {
       OS << "      const Attribute::AttrKind Atts[] = {";
       bool addComma = false;
       if (!intrinsic.canThrow) {
@@ -625,6 +628,12 @@
         OS << "Attribute::Convergent";
         addComma = true;
       }
+      if (intrinsic.isSpeculatable) {
+        if (addComma)
+          OS << ",";
+        OS << "Attribute::Speculatable";
+        addComma = true;
+      }
 
       switch (intrinsic.ModRef) {
       case CodeGenIntrinsic::NoMem: