diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index eba4db9..ec1040e 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -44762,7 +44762,7 @@
 
   // We can only do this if the vector size in 256 bits or less.
   unsigned Size = VT.getSizeInBits();
-  if (Size > 256)
+  if (Size > 256 && Subtarget.useAVX512Regs())
     return SDValue();
 
   // Don't fold if the condition code can't be handled by PCMPEQ/PCMPGT since
diff --git a/llvm/test/CodeGen/X86/min-legal-vector-width.ll b/llvm/test/CodeGen/X86/min-legal-vector-width.ll
index 44ed303..81de0ee 100644
--- a/llvm/test/CodeGen/X86/min-legal-vector-width.ll
+++ b/llvm/test/CodeGen/X86/min-legal-vector-width.ll
@@ -1600,3 +1600,43 @@
   %4 = load i32, i32* %1, align 4
   ret i32 %4
 }
+
+define void @cmp_v8i64_sext(<8 x i64>* %xptr, <8 x i64>* %yptr, <8 x i64>* %zptr) "min-legal-vector-width"="256" {
+; CHECK-LABEL: cmp_v8i64_sext:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vmovdqa (%rsi), %ymm0
+; CHECK-NEXT:    vmovdqa 32(%rsi), %ymm1
+; CHECK-NEXT:    vpcmpgtq 32(%rdi), %ymm1, %ymm1
+; CHECK-NEXT:    vpcmpgtq (%rdi), %ymm0, %ymm0
+; CHECK-NEXT:    vmovdqa %ymm0, (%rdx)
+; CHECK-NEXT:    vmovdqa %ymm1, 32(%rdx)
+; CHECK-NEXT:    vzeroupper
+; CHECK-NEXT:    retq
+  %x = load <8 x i64>, <8 x i64>* %xptr
+  %y = load <8 x i64>, <8 x i64>* %yptr
+  %cmp = icmp slt <8 x i64> %x, %y
+  %ext = sext <8 x i1> %cmp to <8 x i64>
+  store <8 x i64> %ext, <8 x i64>* %zptr
+  ret void
+}
+
+define void @cmp_v8i64_zext(<8 x i64>* %xptr, <8 x i64>* %yptr, <8 x i64>* %zptr) "min-legal-vector-width"="256" {
+; CHECK-LABEL: cmp_v8i64_zext:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vmovdqa (%rsi), %ymm0
+; CHECK-NEXT:    vmovdqa 32(%rsi), %ymm1
+; CHECK-NEXT:    vpcmpgtq 32(%rdi), %ymm1, %ymm1
+; CHECK-NEXT:    vpcmpgtq (%rdi), %ymm0, %ymm0
+; CHECK-NEXT:    vpsrlq $63, %ymm1, %ymm1
+; CHECK-NEXT:    vpsrlq $63, %ymm0, %ymm0
+; CHECK-NEXT:    vmovdqa %ymm0, (%rdx)
+; CHECK-NEXT:    vmovdqa %ymm1, 32(%rdx)
+; CHECK-NEXT:    vzeroupper
+; CHECK-NEXT:    retq
+  %x = load <8 x i64>, <8 x i64>* %xptr
+  %y = load <8 x i64>, <8 x i64>* %yptr
+  %cmp = icmp slt <8 x i64> %x, %y
+  %ext = zext <8 x i1> %cmp to <8 x i64>
+  store <8 x i64> %ext, <8 x i64>* %zptr
+  ret void
+}