diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -1178,9 +1178,11 @@
       FunctionCallee Fn = MS.MaybeStoreOriginFn[SizeIndex];
       Value *ConvertedShadow2 =
           IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
-      IRB.CreateCall(Fn,
-                     {ConvertedShadow2,
-                      IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()), Origin});
+      CallBase *CB = IRB.CreateCall(
+          Fn, {ConvertedShadow2,
+               IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()), Origin});
+      CB->addAttribute(AttributeList::FirstArgIndex, Attribute::ZExt);
+      CB->addAttribute(AttributeList::FirstArgIndex + 2, Attribute::ZExt);
     } else {
       Value *Cmp = convertToBool(ConvertedShadow, IRB, "_mscmp");
       Instruction *CheckTerm = SplitBlockAndInsertIfThen(
@@ -1250,9 +1252,11 @@
       FunctionCallee Fn = MS.MaybeWarningFn[SizeIndex];
       Value *ConvertedShadow2 =
           IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
-      IRB.CreateCall(Fn, {ConvertedShadow2, MS.TrackOrigins && Origin
-                                                ? Origin
-                                                : (Value *)IRB.getInt32(0)});
+      CallBase *CB = IRB.CreateCall(
+          Fn, {ConvertedShadow2,
+               MS.TrackOrigins && Origin ? Origin : (Value *)IRB.getInt32(0)});
+      CB->addAttribute(AttributeList::FirstArgIndex, Attribute::ZExt);
+      CB->addAttribute(AttributeList::FirstArgIndex + 1, Attribute::ZExt);
     } else {
       Value *Cmp = convertToBool(ConvertedShadow, IRB, "_mscmp");
       Instruction *CheckTerm = SplitBlockAndInsertIfThen(
diff --git a/llvm/test/Instrumentation/MemorySanitizer/instrumentation-with-call-threshold.ll b/llvm/test/Instrumentation/MemorySanitizer/instrumentation-with-call-threshold.ll
--- a/llvm/test/Instrumentation/MemorySanitizer/instrumentation-with-call-threshold.ll
+++ b/llvm/test/Instrumentation/MemorySanitizer/instrumentation-with-call-threshold.ll
@@ -40,7 +40,7 @@
 ; CHECK: = load
 ; CHECK: = load
 ; CHECK: = zext i1 {{.*}} to i8
-; CHECK: call void @__msan_maybe_warning_1(
+; CHECK: call void @__msan_maybe_warning_1(i8 zeroext {{.*}}, i32 zeroext {{.*}})
 ; CHECK-NOT: unreachable
 ; CHECK: ret void
 
@@ -58,7 +58,7 @@
 ; CHECK-ORIGINS-NOT: __msan_chain_origin
 ; CHECK-ORIGINS: bitcast i64* {{.*}} to i8*
 ; CHECK-ORIGINS-NOT: __msan_chain_origin
-; CHECK-ORIGINS: call void @__msan_maybe_store_origin_8(
+; CHECK-ORIGINS: call void @__msan_maybe_store_origin_8(i64 zeroext {{.*}}, i8* {{.*}}, i32 zeroext {{.*}})
 ; CHECK-ORIGINS-NOT: __msan_chain_origin
 ; CHECK: store i64
 ; CHECK: ret void
diff --git a/llvm/test/Instrumentation/MemorySanitizer/with-call-type-size.ll b/llvm/test/Instrumentation/MemorySanitizer/with-call-type-size.ll
--- a/llvm/test/Instrumentation/MemorySanitizer/with-call-type-size.ll
+++ b/llvm/test/Instrumentation/MemorySanitizer/with-call-type-size.ll
@@ -11,7 +11,7 @@
 }
 ; CHECK-LABEL: @test1(
 ; CHECK:         %[[A:.*]] = zext i1 {{.*}} to i8
-; CHECK:         call void @__msan_maybe_warning_1(i8 %[[A]], i32 0)
+; CHECK:         call void @__msan_maybe_warning_1(i8 zeroext %[[A]], i32 zeroext 0)
 ; CHECK:         ret <4 x i32>
 
 define <4 x i32> @test2(<4 x i32> %vec, i2 %idx, i32 %x) sanitize_memory {
@@ -20,7 +20,7 @@
 }
 ; CHECK-LABEL: @test2(
 ; CHECK:         %[[A:.*]] = zext i2 {{.*}} to i8
-; CHECK:         call void @__msan_maybe_warning_1(i8 %[[A]], i32 0)
+; CHECK:         call void @__msan_maybe_warning_1(i8 zeroext %[[A]], i32 zeroext 0)
 ; CHECK:         ret <4 x i32>
 
 define <4 x i32> @test8(<4 x i32> %vec, i8 %idx, i32 %x) sanitize_memory {
@@ -29,7 +29,7 @@
 }
 ; CHECK-LABEL: @test8(
 ; zext i8 -> i8 unnecessary.
-; CHECK:         call void @__msan_maybe_warning_1(i8 %{{.*}}, i32 0)
+; CHECK:         call void @__msan_maybe_warning_1(i8 zeroext %{{.*}}, i32 zeroext 0)
 ; CHECK:         ret <4 x i32>
 
 define <4 x i32> @test9(<4 x i32> %vec, i9 %idx, i32 %x) sanitize_memory {
@@ -38,7 +38,7 @@
 }
 ; CHECK-LABEL: @test9(
 ; CHECK:         %[[A:.*]] = zext i9 {{.*}} to i16
-; CHECK:         call void @__msan_maybe_warning_2(i16 %[[A]], i32 0)
+; CHECK:         call void @__msan_maybe_warning_2(i16 zeroext %[[A]], i32 zeroext 0)
 ; CHECK:         ret <4 x i32>
 
 define <4 x i32> @test16(<4 x i32> %vec, i16 %idx, i32 %x) sanitize_memory {
@@ -46,7 +46,7 @@
   ret <4 x i32> %vec1
 }
 ; CHECK-LABEL: @test16(
-; CHECK:         call void @__msan_maybe_warning_2(i16 %{{.*}}, i32 0)
+; CHECK:         call void @__msan_maybe_warning_2(i16 zeroext %{{.*}}, i32 zeroext 0)
 ; CHECK:         ret <4 x i32>
 
 define <4 x i32> @test17(<4 x i32> %vec, i17 %idx, i32 %x) sanitize_memory {
@@ -55,7 +55,7 @@
 }
 ; CHECK-LABEL: @test17(
 ; CHECK:         %[[A:.*]] = zext i17 {{.*}} to i32
-; CHECK:         call void @__msan_maybe_warning_4(i32 %[[A]], i32 0)
+; CHECK:         call void @__msan_maybe_warning_4(i32 zeroext %[[A]], i32 zeroext 0)
 ; CHECK:         ret <4 x i32>
 
 define <4 x i32> @test42(<4 x i32> %vec, i42 %idx, i32 %x) sanitize_memory {
@@ -64,7 +64,7 @@
 }
 ; CHECK-LABEL: @test42(
 ; CHECK:         %[[A:.*]] = zext i42 {{.*}} to i64
-; CHECK:         call void @__msan_maybe_warning_8(i64 %[[A]], i32 0)
+; CHECK:         call void @__msan_maybe_warning_8(i64 zeroext %[[A]], i32 zeroext 0)
 ; CHECK:         ret <4 x i32>
 
 define <4 x i32> @test64(<4 x i32> %vec, i64 %idx, i32 %x) sanitize_memory {
@@ -72,7 +72,7 @@
   ret <4 x i32> %vec1
 }
 ; CHECK-LABEL: @test64(
-; CHECK:         call void @__msan_maybe_warning_8(i64 %{{.*}}, i32 0)
+; CHECK:         call void @__msan_maybe_warning_8(i64 zeroext %{{.*}}, i32 zeroext 0)
 ; CHECK:         ret <4 x i32>
 
 ; Type size too large => inline check.