Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -7168,6 +7168,14 @@
   return EmitX86Select(CGF, Ops[3], Res, Ops[2]);
 }
 
+static Value *EmitX86SExtMask(CodeGenFunction &CGF, llvm::IntegerType *IT,
+                              Value *Op, llvm::Type *DstTy) {
+  unsigned NumberOfElements = DstTy->getVectorNumElements();
+  Value *Mask = getMaskVecValue(CGF, Op, NumberOfElements);
+  return CGF.Builder.CreateSExt(
+      Mask, llvm::VectorType::get(IT, NumberOfElements), "vpmovm2");
+}
+
 Value *CodeGenFunction::EmitX86BuiltinExpr(unsigned BuiltinID,
                                            const CallExpr *E) {
   if (BuiltinID == X86::BI__builtin_ms_va_start ||
@@ -7466,6 +7474,24 @@
   case X86::BI__builtin_ia32_storesd128_mask: {
     return EmitX86MaskedStore(*this, Ops, 16);
   }
+
+  case X86::BI__builtin_ia32_cvtmask2b128:
+  case X86::BI__builtin_ia32_cvtmask2b256:
+  case X86::BI__builtin_ia32_cvtmask2b512:
+    return EmitX86SExtMask(*this, Int8Ty, Ops[0], ConvertType(E->getType()));
+  case X86::BI__builtin_ia32_cvtmask2w128:
+  case X86::BI__builtin_ia32_cvtmask2w256:
+  case X86::BI__builtin_ia32_cvtmask2w512:
+    return EmitX86SExtMask(*this, Int16Ty, Ops[0], ConvertType(E->getType()));
+  case X86::BI__builtin_ia32_cvtmask2d128:
+  case X86::BI__builtin_ia32_cvtmask2d256:
+  case X86::BI__builtin_ia32_cvtmask2d512:
+    return EmitX86SExtMask(*this, Int32Ty, Ops[0], ConvertType(E->getType()));
+  case X86::BI__builtin_ia32_cvtmask2q128:
+  case X86::BI__builtin_ia32_cvtmask2q256:
+  case X86::BI__builtin_ia32_cvtmask2q512:
+    return EmitX86SExtMask(*this, Int64Ty, Ops[0], ConvertType(E->getType()));
+
   case X86::BI__builtin_ia32_movdqa32store128_mask:
   case X86::BI__builtin_ia32_movdqa64store128_mask:
   case X86::BI__builtin_ia32_storeaps128_mask:
Index: test/CodeGen/avx512bw-builtins.c
===================================================================
--- test/CodeGen/avx512bw-builtins.c
+++ test/CodeGen/avx512bw-builtins.c
@@ -1543,13 +1543,15 @@
 
 __m512i test_mm512_movm_epi8(__mmask64 __A) {
   // CHECK-LABEL: @test_mm512_movm_epi8
-  // CHECK: @llvm.x86.avx512.cvtmask2b.512
+  // CHECK:  %2 = bitcast i64 %1 to <64 x i1>
+  // CHECK:  %vpmovm2.i = sext <64 x i1> %2 to <64 x i8>
   return _mm512_movm_epi8(__A); 
 }
 
 __m512i test_mm512_movm_epi16(__mmask32 __A) {
   // CHECK-LABEL: @test_mm512_movm_epi16
-  // CHECK: @llvm.x86.avx512.cvtmask2w.512
+  // CHECK:  %2 = bitcast i32 %1 to <32 x i1>
+  // CHECK:  %vpmovm2.i = sext <32 x i1> %2 to <32 x i16>
   return _mm512_movm_epi16(__A); 
 }
 
Index: test/CodeGen/avx512dq-builtins.c
===================================================================
--- test/CodeGen/avx512dq-builtins.c
+++ test/CodeGen/avx512dq-builtins.c
@@ -929,13 +929,15 @@
 
 __m512i test_mm512_movm_epi32(__mmask16 __A) {
   // CHECK-LABEL: @test_mm512_movm_epi32
-  // CHECK: @llvm.x86.avx512.cvtmask2d.512
+  // CHECK: %2 = bitcast i16 %1 to <16 x i1>
+  // CHECK: %vpmovm2.i = sext <16 x i1> %2 to <16 x i32>
   return _mm512_movm_epi32(__A); 
 }
 
 __m512i test_mm512_movm_epi64(__mmask8 __A) {
   // CHECK-LABEL: @test_mm512_movm_epi64
-  // CHECK: @llvm.x86.avx512.cvtmask2q.512
+  // CHECK: %2 = bitcast i8 %1 to <8 x i1>
+  // CHECK: %vpmovm2.i = sext <8 x i1> %2 to <8 x i64>
   return _mm512_movm_epi64(__A); 
 }
 
Index: test/CodeGen/avx512vlbw-builtins.c
===================================================================
--- test/CodeGen/avx512vlbw-builtins.c
+++ test/CodeGen/avx512vlbw-builtins.c
@@ -2521,25 +2521,29 @@
 
 __m128i test_mm_movm_epi8(__mmask16 __A) {
   // CHECK-LABEL: @test_mm_movm_epi8
-  // CHECK: @llvm.x86.avx512.cvtmask2b.128
+  // CHECK: %2 = bitcast i16 %1 to <16 x i1>
+  // CHECK: %vpmovm2.i = sext <16 x i1> %2 to <16 x i8>
   return _mm_movm_epi8(__A); 
 }
 
 __m256i test_mm256_movm_epi8(__mmask32 __A) {
   // CHECK-LABEL: @test_mm256_movm_epi8
-  // CHECK: @llvm.x86.avx512.cvtmask2b.256
+  // CHECK: %2 = bitcast i32 %1 to <32 x i1>
+  // CHECK: %vpmovm2.i = sext <32 x i1> %2 to <32 x i8>
   return _mm256_movm_epi8(__A); 
 }
 
 __m128i test_mm_movm_epi16(__mmask8 __A) {
   // CHECK-LABEL: @test_mm_movm_epi16
-  // CHECK: @llvm.x86.avx512.cvtmask2w.128
+  // CHECK: %2 = bitcast i8 %1 to <8 x i1>
+  // CHECK: %vpmovm2.i = sext <8 x i1> %2 to <8 x i16>
   return _mm_movm_epi16(__A); 
 }
 
 __m256i test_mm256_movm_epi16(__mmask16 __A) {
   // CHECK-LABEL: @test_mm256_movm_epi16
-  // CHECK: @llvm.x86.avx512.cvtmask2w.256
+  // CHECK: %2 = bitcast i16 %1 to <16 x i1>
+  // CHECK: %vpmovm2.i = sext <16 x i1> %2 to <16 x i16>
   return _mm256_movm_epi16(__A); 
 }
 
Index: test/CodeGen/avx512vldq-builtins.c
===================================================================
--- test/CodeGen/avx512vldq-builtins.c
+++ test/CodeGen/avx512vldq-builtins.c
@@ -865,25 +865,32 @@
 
 __m128i test_mm_movm_epi32(__mmask8 __A) {
   // CHECK-LABEL: @test_mm_movm_epi32
-  // CHECK: @llvm.x86.avx512.cvtmask2d.128
+  // CHECK: %2 = bitcast i8 %1 to <8 x i1>
+  // CHECK: %extract.i = shufflevector <8 x i1> %2, <8 x i1> %2, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+  // CHECK: %vpmovm2.i = sext <4 x i1> %extract.i to <4 x i32>
   return _mm_movm_epi32(__A); 
 }
 
 __m256i test_mm256_movm_epi32(__mmask8 __A) {
   // CHECK-LABEL: @test_mm256_movm_epi32
-  // CHECK: @llvm.x86.avx512.cvtmask2d.256
+  // CHECK: %2 = bitcast i8 %1 to <8 x i1>
+  // CHECK: %vpmovm2.i = sext <8 x i1> %2 to <8 x i32>
   return _mm256_movm_epi32(__A); 
 }
 
 __m128i test_mm_movm_epi64(__mmask8 __A) {
   // CHECK-LABEL: @test_mm_movm_epi64
-  // CHECK: @llvm.x86.avx512.cvtmask2q.128
+  // CHECK: %2 = bitcast i8 %1 to <8 x i1>
+  // CHECK: %extract.i = shufflevector <8 x i1> %2, <8 x i1> %2, <2 x i32> <i32 0, i32 1>
+  // CHECK: %vpmovm2.i = sext <2 x i1> %extract.i to <2 x i64>
   return _mm_movm_epi64(__A); 
 }
 
 __m256i test_mm256_movm_epi64(__mmask8 __A) {
   // CHECK-LABEL: @test_mm256_movm_epi64
-  // CHECK: @llvm.x86.avx512.cvtmask2q.256
+  // CHECK: %2 = bitcast i8 %1 to <8 x i1>
+  // CHECK: %extract.i = shufflevector <8 x i1> %2, <8 x i1> %2, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+  // CHECK: %vpmovm2.i = sext <4 x i1> %extract.i to <4 x i64>
   return _mm256_movm_epi64(__A); 
 }