Index: lib/CodeGen/CodeGenPrepare.cpp
===================================================================
--- lib/CodeGen/CodeGenPrepare.cpp
+++ lib/CodeGen/CodeGenPrepare.cpp
@@ -3596,8 +3596,14 @@
 
   // Remember the original type of the instruction before promotion.
   // This is useful to know that the high bits are sign extended bits.
-  PromotedInsts.insert(std::pair<Instruction *, TypeIsSExt>(
-      ExtOpnd, TypeIsSExt(ExtOpnd->getType(), IsSExt)));
+  // If the instruction has conflict extension types, remove it.
+  InstrToOrigTy::iterator It = PromotedInsts.find(ExtOpnd);
+  if (It == PromotedInsts.end())
+    PromotedInsts.insert(std::pair<Instruction *, TypeIsSExt>(
+        ExtOpnd, TypeIsSExt(ExtOpnd->getType(), IsSExt)));
+  else if (It->second.getInt() != IsSExt)
+    PromotedInsts.erase(It);
+
   // Step #1.
   TPT.mutateType(ExtOpnd, Ext->getType());
   // Step #2.
Index: test/Transforms/CodeGenPrepare/X86/pr38125.ll
===================================================================
--- test/Transforms/CodeGenPrepare/X86/pr38125.ll
+++ test/Transforms/CodeGenPrepare/X86/pr38125.ll
@@ -0,0 +1,32 @@
+; RUN: opt < %s -codegenprepare -S -mtriple=x86_64-unknown-unknown    | FileCheck %s
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.13.0"
+
+declare void @bar(i64)
+
+@b = global i16 0, align 2
+
+; CHECK:       %promoted = trunc i32 %or to i16
+; CHECK-NEXT:  %c = sext i16 %promoted to i64
+define i32 @foo() {
+entry:
+  %cmp6 = icmp sgt i32 0, -1
+  br i1 %cmp6, label %t, label %f
+
+f:
+  br label %end
+
+t:
+  br label %end
+
+end:
+  %t3 = phi i16 [ 0, %f ], [ -3, %t ]
+  %t4 = load i16, i16* @b, align 2
+  %conv4 = zext i16 %t4 to i32
+  %or = or i16 %t3, %t4
+  %c = sext i16 %or to i64
+  call void @bar(i64 %c)
+  %t5 = and i16 %or, 5
+  %z = zext i16 %t5 to i32
+  ret i32 %z
+}