diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 4f04ce34fc6..a3d24cc7b42 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -420,7 +420,8 @@ public:
   }
 
   /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
-  /// function arguments in the caller parameter area.
+  /// function arguments in the caller parameter area.  This is the actual
+  /// alignment, not its logarithm.
   virtual unsigned getByValTypeAlignment(const Type *Ty) const;
   
   /// getRegisterType - Return the type of registers that this ValueType will
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index ff5289e0882..61a155e978c 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -424,9 +424,10 @@ unsigned TargetLowering::getVectorTypeBreakdown(MVT::ValueType VT,
 }
 
 /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
-/// function arguments in the caller parameter area.
+/// function arguments in the caller parameter area.  This is the actual
+/// alignment, not its logarithm.
 unsigned TargetLowering::getByValTypeAlignment(const Type *Ty) const {
-  return Log2_32(TD->getCallFrameTypeAlignment(Ty));
+  return TD->getCallFrameTypeAlignment(Ty);
 }
 
 SDOperand TargetLowering::getPICJumpTableRelocBase(SDOperand Table,
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 5500e37aaec..675c96a9b9f 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -351,6 +351,17 @@ PPCTargetLowering::PPCTargetLowering(PPCTargetMachine &TM)
   computeRegisterProperties();
 }
 
+/// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
+/// function arguments in the caller parameter area.
+unsigned PPCTargetLowering::getByValTypeAlignment(const Type *Ty) const {
+  TargetMachine &TM = getTargetMachine();
+  // Darwin passes everything on 4 byte boundary.
+  if (TM.getSubtarget<PPCSubtarget>().isDarwin())
+    return 4;
+  // FIXME Elf TBD
+  return 4;
+}
+
 const char *PPCTargetLowering::getTargetNodeName(unsigned Opcode) const {
   switch (Opcode) {
   default: return 0;
diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index 3843998b508..9c539584a1f 100644
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -268,6 +268,11 @@ namespace llvm {
       getRegForInlineAsmConstraint(const std::string &Constraint,
                                    MVT::ValueType VT) const;
 
+    /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
+    /// function arguments in the caller parameter area.  This is the actual
+    /// alignment, not its logarithm.
+    unsigned getByValTypeAlignment(const Type *Ty) const;
+
     /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
     /// vector.  If it is invalid, don't add anything to Ops.
     virtual void LowerAsmOperandForConstraint(SDOperand Op,