3 files changed, 19 insertions, 4 deletions
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index 7f1709e10f..0d5be26a5e 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -1293,10 +1293,17 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
   case Builtin::BIpow:
   case Builtin::BIpowf:
   case Builtin::BIpowl: {
-    // LOCALMOD: For PNACl we don't want pow* calls to ever turn into
-    // intrinsics. We want them to be resolved vs. the newlib implementation
-    // within the pexe during bitcode linking.
-    // TODO(eliben): upstream this
+    // Transform a call to pow* into a @llvm.pow.* intrinsic call, but only
+    // if the target agrees.
+    if (getTargetHooks().emitIntrinsicForPow()) {
+      if (!FD->hasAttr<ConstAttr>())
+        break;
+      Value *Base = EmitScalarExpr(E->getArg(0));
+      Value *Exponent = EmitScalarExpr(E->getArg(1));
+      llvm::Type *ArgType = Base->getType();
+      Value *F = CGM.getIntrinsic(Intrinsic::pow, ArgType);
+      return RValue::get(Builder.CreateCall2(F, Base, Exponent));
+    }
     break;
   }
 
diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp
index b870ae9eb1..6ca2910d79 100644
--- a/lib/CodeGen/TargetInfo.cpp
+++ b/lib/CodeGen/TargetInfo.cpp
@@ -416,6 +416,10 @@ class PNaClTargetCodeGenInfo : public TargetCodeGenInfo {
  public:
   PNaClTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
     : TargetCodeGenInfo(new PNaClABIInfo(CGT)) {}
+
+  /// For PNaCl we don't want llvm.pow.* intrinsics to be emitted instead
+  /// of library function calls.
+  bool emitIntrinsicForPow() const { return false; }
 };
 
 void PNaClABIInfo::computeInfo(CGFunctionInfo &FI) const {
diff --git a/lib/CodeGen/TargetInfo.h b/lib/CodeGen/TargetInfo.h
index bb50ce69e3..a682c183f0 100644
--- a/lib/CodeGen/TargetInfo.h
+++ b/lib/CodeGen/TargetInfo.h
@@ -73,6 +73,10 @@ namespace clang {
     ///     through such registers.
     virtual bool extendPointerWithSExt() const { return false; }
 
+    /// Controls whether BIpow* emit an intrinsic call instead of a library
+    /// function call.
+    virtual bool emitIntrinsicForPow() const { return true; }
+
     /// Determines the DWARF register number for the stack pointer, for
     /// exception-handling purposes.  Implements __builtin_dwarf_sp_column.
     ///