diff --git a/llvm/lib/Target/X86/X86InstrFPStack.td b/llvm/lib/Target/X86/X86InstrFPStack.td
index 2224a08d59f4..dfff537f9074 100644
--- a/llvm/lib/Target/X86/X86InstrFPStack.td
+++ b/llvm/lib/Target/X86/X86InstrFPStack.td
@@ -578,7 +578,7 @@ def COM_FIPr : FPI<0xF0, AddRegFrm, (outs), (ins RST:$reg),
 let SchedRW = [WriteALU] in {
 let Defs = [AX], Uses = [FPSW] in
 def FNSTSW16r : I<0xE0, RawFrm,                  // AX = fp flags
-                  (outs), (ins), "fnstsw %ax",
+                  (outs), (ins), "fnstsw\t{%ax|AX}",
                   [(set AX, (X86fp_stsw FPSW))], IIC_FNSTSW>, DF;
 
 def FNSTCW16m : I<0xD9, MRM7m,                   // [mem16] = X87 control world
diff --git a/llvm/lib/Target/X86/X86InstrInfo.td b/llvm/lib/Target/X86/X86InstrInfo.td
index 34547de1bde2..3392a1a8c3a1 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.td
+++ b/llvm/lib/Target/X86/X86InstrInfo.td
@@ -2056,8 +2056,8 @@ def : InstAlias<"fdiv{|r}p\t{%st(0), $op|$op, ST(0)}", (DIVR_FPrST0 RST:$op)>;
 def : InstAlias<"fdiv{r|}p\t{%st(0), $op|$op, ST(0)}", (DIV_FPrST0 RST:$op)>;
 
 // We accept "fnstsw %eax" even though it only writes %ax.
-def : InstAlias<"fnstsw %eax", (FNSTSW16r)>;
-def : InstAlias<"fnstsw %al" , (FNSTSW16r)>;
+def : InstAlias<"fnstsw\t{%eax|EAX}", (FNSTSW16r)>;
+def : InstAlias<"fnstsw\t{%al|AL}" , (FNSTSW16r)>;
 def : InstAlias<"fnstsw"     , (FNSTSW16r)>;
 
 // lcall and ljmp aliases.  This seems to be an odd mapping in 64-bit mode, but
@@ -2186,19 +2186,19 @@ defm : ShiftRotateByOneAlias<"ror", "ROR">;
 FIXME */
 
 // test: We accept "testX <reg>, <mem>" and "testX <mem>, <reg>" as synonyms.
-def : InstAlias<"testb $val, $mem", (TEST8rm  GR8 :$val, i8mem :$mem)>;
-def : InstAlias<"testw $val, $mem", (TEST16rm GR16:$val, i16mem:$mem)>;
-def : InstAlias<"testl $val, $mem", (TEST32rm GR32:$val, i32mem:$mem)>;
-def : InstAlias<"testq $val, $mem", (TEST64rm GR64:$val, i64mem:$mem)>;
+def : InstAlias<"test{b}\t{$val, $mem|$mem, $val}", (TEST8rm  GR8 :$val, i8mem :$mem)>;
+def : InstAlias<"test{w}\t{$val, $mem|$mem, $val}", (TEST16rm GR16:$val, i16mem:$mem)>;
+def : InstAlias<"test{l}\t{$val, $mem|$mem, $val}", (TEST32rm GR32:$val, i32mem:$mem)>;
+def : InstAlias<"test{q}\t{$val, $mem|$mem, $val}", (TEST64rm GR64:$val, i64mem:$mem)>;
 
 // xchg: We accept "xchgX <reg>, <mem>" and "xchgX <mem>, <reg>" as synonyms.
-def : InstAlias<"xchgb $mem, $val", (XCHG8rm  GR8 :$val, i8mem :$mem)>;
-def : InstAlias<"xchgw $mem, $val", (XCHG16rm GR16:$val, i16mem:$mem)>;
-def : InstAlias<"xchgl $mem, $val", (XCHG32rm GR32:$val, i32mem:$mem)>;
-def : InstAlias<"xchgq $mem, $val", (XCHG64rm GR64:$val, i64mem:$mem)>;
+def : InstAlias<"xchg{b}\t{$mem, $val|$val, $mem}", (XCHG8rm  GR8 :$val, i8mem :$mem)>;
+def : InstAlias<"xchg{w}\t{$mem, $val|$val, $mem}", (XCHG16rm GR16:$val, i16mem:$mem)>;
+def : InstAlias<"xchg{l}\t{$mem, $val|$val, $mem}", (XCHG32rm GR32:$val, i32mem:$mem)>;
+def : InstAlias<"xchg{q}\t{$mem, $val|$val, $mem}", (XCHG64rm GR64:$val, i64mem:$mem)>;
 
 // xchg: We accept "xchgX <reg>, %eax" and "xchgX %eax, <reg>" as synonyms.
-def : InstAlias<"xchgw %ax, $src", (XCHG16ar GR16:$src)>;
-def : InstAlias<"xchgl %eax, $src", (XCHG32ar GR32:$src)>, Requires<[In32BitMode]>;
-def : InstAlias<"xchgl %eax, $src", (XCHG32ar64 GR32_NOAX:$src)>, Requires<[In64BitMode]>;
-def : InstAlias<"xchgq %rax, $src", (XCHG64ar GR64:$src)>;
+def : InstAlias<"xchg{w}\t{%ax, $src|$src, AX}", (XCHG16ar GR16:$src)>;
+def : InstAlias<"xchg{l}\t{%eax, $src|$src, EAX}", (XCHG32ar GR32:$src)>, Requires<[In32BitMode]>;
+def : InstAlias<"xchg{l}\t{%eax, $src|$src, EAX}", (XCHG32ar64 GR32_NOAX:$src)>, Requires<[In64BitMode]>;
+def : InstAlias<"xchg{q}\t{%rax, $src|$src, RAX}", (XCHG64ar GR64:$src)>;
diff --git a/llvm/lib/Target/X86/X86InstrSSE.td b/llvm/lib/Target/X86/X86InstrSSE.td
index 8fdcdd4ba8b6..e14cb10b744b 100644
--- a/llvm/lib/Target/X86/X86InstrSSE.td
+++ b/llvm/lib/Target/X86/X86InstrSSE.td
@@ -5477,12 +5477,12 @@ def MWAITrr   : I<0x01, MRM_C9, (outs), (ins), "mwait",
                 TB, Requires<[HasSSE3]>;
 } // SchedRW
 
-def : InstAlias<"mwait %eax, %ecx", (MWAITrr)>, Requires<[In32BitMode]>;
-def : InstAlias<"mwait %rax, %rcx", (MWAITrr)>, Requires<[In64BitMode]>;
+def : InstAlias<"mwait\t{%eax, %ecx|ECX, EAX}", (MWAITrr)>, Requires<[In32BitMode]>;
+def : InstAlias<"mwait\t{%rax, %rcx|RCX, RAX}", (MWAITrr)>, Requires<[In64BitMode]>;
 
-def : InstAlias<"monitor %eax, %ecx, %edx", (MONITORrrr)>,
+def : InstAlias<"monitor\t{%eax, %ecx, %edx|EDX, ECX, EAX}", (MONITORrrr)>,
       Requires<[In32BitMode]>;
-def : InstAlias<"monitor %rax, %rcx, %rdx", (MONITORrrr)>,
+def : InstAlias<"monitor\t{%rax, %rcx, %rdx|RDX, RCX, RAX}", (MONITORrrr)>,
       Requires<[In64BitMode]>;
 
 //===----------------------------------------------------------------------===//