diff --git a/lib/CodeGen/BasicTargetTransformInfo.cpp b/lib/CodeGen/BasicTargetTransformInfo.cpp
index 03c5eba3692..25486cf3919 100644
--- a/lib/CodeGen/BasicTargetTransformInfo.cpp
+++ b/lib/CodeGen/BasicTargetTransformInfo.cpp
@@ -297,7 +297,8 @@ unsigned BasicTTI::getCastInstrCost(unsigned Opcode, Type *Dst,
     return 0;
 
   // If the cast is marked as legal (or promote) then assume low cost.
-  if (TLI->isOperationLegalOrPromote(ISD, DstLT.second))
+  if (SrcLT.first == DstLT.first &&
+      TLI->isOperationLegalOrPromote(ISD, DstLT.second))
     return 1;
 
   // Handle scalar conversions.
diff --git a/test/Analysis/CostModel/PowerPC/ext.ll b/test/Analysis/CostModel/PowerPC/ext.ll
new file mode 100644
index 00000000000..daaa8f5bac3
--- /dev/null
+++ b/test/Analysis/CostModel/PowerPC/ext.ll
@@ -0,0 +1,21 @@
+; RUN: opt < %s -cost-model -analyze -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 -mattr=+vsx | FileCheck %s
+target datalayout = "E-m:e-i64:64-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+define void @exts() {
+
+  ; CHECK: cost of 1 {{.*}} sext
+  %v1 = sext i16 undef to i32
+
+  ; CHECK: cost of 1 {{.*}} sext
+  %v2 = sext <2 x i16> undef to <2 x i32>
+
+  ; CHECK: cost of 1 {{.*}} sext
+  %v3 = sext <4 x i16> undef to <4 x i32>
+
+  ; CHECK: cost of 216 {{.*}} sext
+  %v4 = sext <8 x i16> undef to <8 x i32>
+
+  ret void
+}
+