diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index 7049858355d..f585b476630 100644
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -1855,20 +1855,20 @@ def : InstAlias<"outl $port", (OUT32ir i8imm:$port)>;
 // errors, since its encoding is the most compact.
 def : InstAlias<"sldt $mem", (SLDT16m i16mem:$mem)>;
 
-// shld/shrd op,op -> shld op, op, 1
-def : InstAlias<"shldw $r1, $r2", (SHLD16rri8 GR16:$r1, GR16:$r2, 1)>;
-def : InstAlias<"shldl $r1, $r2", (SHLD32rri8 GR32:$r1, GR32:$r2, 1)>;
-def : InstAlias<"shldq $r1, $r2", (SHLD64rri8 GR64:$r1, GR64:$r2, 1)>;
-def : InstAlias<"shrdw $r1, $r2", (SHRD16rri8 GR16:$r1, GR16:$r2, 1)>;
-def : InstAlias<"shrdl $r1, $r2", (SHRD32rri8 GR32:$r1, GR32:$r2, 1)>;
-def : InstAlias<"shrdq $r1, $r2", (SHRD64rri8 GR64:$r1, GR64:$r2, 1)>;
+// shld/shrd op,op -> shld op, op, CL
+def : InstAlias<"shldw $r1, $r2", (SHLD16rrCL GR16:$r1, GR16:$r2)>;
+def : InstAlias<"shldl $r1, $r2", (SHLD32rrCL GR32:$r1, GR32:$r2)>;
+def : InstAlias<"shldq $r1, $r2", (SHLD64rrCL GR64:$r1, GR64:$r2)>;
+def : InstAlias<"shrdw $r1, $r2", (SHRD16rrCL GR16:$r1, GR16:$r2)>;
+def : InstAlias<"shrdl $r1, $r2", (SHRD32rrCL GR32:$r1, GR32:$r2)>;
+def : InstAlias<"shrdq $r1, $r2", (SHRD64rrCL GR64:$r1, GR64:$r2)>;
 
-def : InstAlias<"shldw $mem, $reg", (SHLD16mri8 i16mem:$mem, GR16:$reg, 1)>;
-def : InstAlias<"shldl $mem, $reg", (SHLD32mri8 i32mem:$mem, GR32:$reg, 1)>;
-def : InstAlias<"shldq $mem, $reg", (SHLD64mri8 i64mem:$mem, GR64:$reg, 1)>;
-def : InstAlias<"shrdw $mem, $reg", (SHRD16mri8 i16mem:$mem, GR16:$reg, 1)>;
-def : InstAlias<"shrdl $mem, $reg", (SHRD32mri8 i32mem:$mem, GR32:$reg, 1)>;
-def : InstAlias<"shrdq $mem, $reg", (SHRD64mri8 i64mem:$mem, GR64:$reg, 1)>;
+def : InstAlias<"shldw $mem, $reg", (SHLD16mrCL i16mem:$mem, GR16:$reg)>;
+def : InstAlias<"shldl $mem, $reg", (SHLD32mrCL i32mem:$mem, GR32:$reg)>;
+def : InstAlias<"shldq $mem, $reg", (SHLD64mrCL i64mem:$mem, GR64:$reg)>;
+def : InstAlias<"shrdw $mem, $reg", (SHRD16mrCL i16mem:$mem, GR16:$reg)>;
+def : InstAlias<"shrdl $mem, $reg", (SHRD32mrCL i32mem:$mem, GR32:$reg)>;
+def : InstAlias<"shrdq $mem, $reg", (SHRD64mrCL i64mem:$mem, GR64:$reg)>;
 
 /*  FIXME: This is disabled because the asm matcher is currently incapable of
  *  matching a fixed immediate like $1.
diff --git a/test/MC/X86/x86-64.s b/test/MC/X86/x86-64.s
index 4ec579a7a1f..d5e1b9c20b1 100644
--- a/test/MC/X86/x86-64.s
+++ b/test/MC/X86/x86-64.s
@@ -339,15 +339,20 @@ rclb	$1, %bl   // CHECK: rclb %bl     # encoding: [0xd0,0xd3]
 rclb	$2, %bl   // CHECK: rclb $2, %bl # encoding: [0xc0,0xd3,0x02]
 
 // rdar://8418316
+// PR12173
+// CHECK: shldw	%cl, %bx, %bx
+// CHECK: shldw	%cl, %bx, %bx
 // CHECK: shldw	$1, %bx, %bx
-// CHECK: shldw	$1, %bx, %bx
-// CHECK: shrdw	$1, %bx, %bx
+// CHECK: shrdw	%cl, %bx, %bx
+// CHECK: shrdw	%cl, %bx, %bx
 // CHECK: shrdw	$1, %bx, %bx
 
-shld	%bx,%bx
-shld	$1, %bx,%bx
-shrd	%bx,%bx
-shrd	$1, %bx,%bx
+shld  %bx, %bx
+shld  %cl, %bx, %bx
+shld  $1, %bx, %bx
+shrd  %bx, %bx
+shrd  %cl, %bx, %bx
+shrd  $1, %bx, %bx
 
 // CHECK: sldtl	%ecx
 // CHECK: encoding: [0x0f,0x00,0xc1]