X86InstrInfo.td

def : InstAlias<"shldl $reg, $mem", (SHLD32mrCL i32mem:$mem, GR32:$reg)>;
def : InstAlias<"shldq $reg, $mem", (SHLD64mrCL i64mem:$mem, GR64:$reg)>;
def : InstAlias<"shrdw $reg, $mem", (SHRD16mrCL i16mem:$mem, GR16:$reg)>;
def : InstAlias<"shrdl $reg, $mem", (SHRD32mrCL i32mem:$mem, GR32:$reg)>;
def : InstAlias<"shrdq $reg, $mem", (SHRD64mrCL i64mem:$mem, GR64:$reg)>;

/*  FIXME: This is disabled because the asm matcher is currently incapable of
 *  matching a fixed immediate like $1.
// "shl X, $1" is an alias for "shl X".
multiclass ShiftRotateByOneAlias<string Mnemonic, string Opc> {
 def : InstAlias<!strconcat(Mnemonic, "b $op, $$1"),
                 (!cast<Instruction>(!strconcat(Opc, "8r1")) GR8:$op)>;
 def : InstAlias<!strconcat(Mnemonic, "w $op, $$1"),
                 (!cast<Instruction>(!strconcat(Opc, "16r1")) GR16:$op)>;
 def : InstAlias<!strconcat(Mnemonic, "l $op, $$1"),
                 (!cast<Instruction>(!strconcat(Opc, "32r1")) GR32:$op)>;
 def : InstAlias<!strconcat(Mnemonic, "q $op, $$1"),
                 (!cast<Instruction>(!strconcat(Opc, "64r1")) GR64:$op)>;
 def : InstAlias<!strconcat(Mnemonic, "b $op, $$1"),
                 (!cast<Instruction>(!strconcat(Opc, "8m1")) i8mem:$op)>;
 def : InstAlias<!strconcat(Mnemonic, "w $op, $$1"),
                 (!cast<Instruction>(!strconcat(Opc, "16m1")) i16mem:$op)>;
 def : InstAlias<!strconcat(Mnemonic, "l $op, $$1"),
                 (!cast<Instruction>(!strconcat(Opc, "32m1")) i32mem:$op)>;
 def : InstAlias<!strconcat(Mnemonic, "q $op, $$1"),
                 (!cast<Instruction>(!strconcat(Opc, "64m1")) i64mem:$op)>;
}

defm : ShiftRotateByOneAlias<"rcl", "RCL">;
defm : ShiftRotateByOneAlias<"rcr", "RCR">;
defm : ShiftRotateByOneAlias<"rol", "ROL">;
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)>;

// 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)>;

// 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)>;