Index: X86TargetTransformInfo.cpp
===================================================================
--- X86TargetTransformInfo.cpp
+++ X86TargetTransformInfo.cpp
@@ -1037,9 +1037,14 @@
   if (BitSize > 128)
     return TCC_Free;
 
-  if (Imm == 0)
+  // Don't hoist imm8
+  if (Imm.isSignedIntN(8))
     return TCC_Free;
 
+  // Don't hoist 1 bit masks. They'll probably be used for BT, BTS, BTC.
+  if (Imm.isPowerOf2())
+    return TCC_Free;
+
   // Sign-extend all constants to a multiple of 64-bit.
   APInt ImmVal = Imm;
   if (BitSize & 0x3f)