diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index 216d0f10e7f..462acb681e7 100644
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -4359,9 +4359,11 @@ def SGDTm : I<0x01, MRM0m, (outs opaque48mem:$dst), (ins),
 def SIDTm : I<0x01, MRM1m, (outs opaque48mem:$dst), (ins),
               "sidt\t$dst", []>, TB;
 def SLDT16r : I<0x00, MRM0r, (outs GR16:$dst), (ins),
-                "sldt{w}\t$dst", []>, TB;
+                "sldt{w}\t$dst", []>, TB, OpSize;
 def SLDT16m : I<0x00, MRM0m, (outs i16mem:$dst), (ins),
                 "sldt{w}\t$dst", []>, TB;
+def SLDT32r : I<0x00, MRM0r, (outs GR32:$dst), (ins),
+                "sldt{l}\t$dst", []>, TB;
 def LGDTm : I<0x01, MRM2m, (outs), (ins opaque48mem:$src),
               "lgdt\t$src", []>, TB;
 def LIDTm : I<0x01, MRM3m, (outs), (ins opaque48mem:$src),
diff --git a/test/MC/AsmParser/X86/x86_instructions.s b/test/MC/AsmParser/X86/x86_instructions.s
index 0f0c1ed76a3..16b1aac6193 100644
--- a/test/MC/AsmParser/X86/x86_instructions.s
+++ b/test/MC/AsmParser/X86/x86_instructions.s
@@ -1,4 +1,4 @@
-// RUN: llvm-mc -triple x86_64-unknown-unknown %s > %t 2> %t.err
+// RUN: llvm-mc -triple x86_64-unknown-unknown -show-encoding %s > %t 2> %t.err
 // RUN: FileCheck < %t %s
 // RUN: FileCheck --check-prefix=CHECK-STDERR < %t.err %s
 
@@ -279,3 +279,12 @@ shld	%bx,%bx
 shld	$1, %bx,%bx
 shrd	%bx,%bx
 shrd	$1, %bx,%bx
+
+// CHECK: sldtl	%ecx
+// CHECK: encoding: [0x0f,0x00,0xc1]
+// CHECK: sldtw	%cx
+// CHECK: encoding: [0x66,0x0f,0x00,0xc1]
+
+sldt	%ecx
+sldt	%cx
+