[ARM] Remove some spurious MVE reduction instructions.

[simon_tatham]

Summary

The family of 'dual-accumulating' vector multiply-add instructions
(VMLADAV, VMLALDAV and VRMLALDAVH) can all operate on both signed and
unsigned integer types, and they all have an 'exchange' variant (with
an X in the name) that modifies which pairs of vector lanes in the two
inputs are multiplied together. But there's a clause in the spec that
says that the X variants don't operate on unsigned integer types,
only signed. You can have X, or unsigned, or neither, but not both.

We didn't notice that clause when we implemented the MC support for
these instructions, so LLVM believes that things like VMLADAVX.U8 do
exist, contradicting the spec. Here I fix that by conditioning them
out in Tablegen.

In order to do that, I've reversed the nesting order of the Tablegen
multiclasses for those instructions. Previously, the innermost
multiclass generated the X and not-X variants, and the one outside
that generated the A and not-A variants. Now X is done by the outer
multiclass, which allows me to bypass that one when I only want the
two not-X variants.

Changing the multiclass nesting order also changes the names of the
instruction ids unless I make a special effort not to. I decided that
while I was changing them anyway I'd make them look nicer; so now the
instructions have names like MVE_VMLADAVs32 or MVE_VMLADAVaxs32,
instead of cumbersome _noacc_noexch suffixes.

The corresponding multiply-subtract instructions are unaffected. Those
don't accept unsigned types at all, either in the spec or in LLVM.

[dmgreen]

Change looks sensible to me, but how difficult would this be to do without the, umm, creative use of foreach?

[ostannard]

LGTM

[simon_tatham]

Reworked the patch to reverse the multiclass nesting order, avoiding the need to fake a Tablegen if using foreach.

[dmgreen]

Nice one. LGTM.

llvm/trunk/lib/Target/ARM/ARMInstrMVE.td

class MVE_VMLAMLSDAV<string iname, string suffix, dag iops, string cstr,
   let Inst{12} = X;
   let Inst{8} = bit_8;
   let Inst{7-6} = 0b00;
   let Inst{5} = A;
   let Inst{3-1} = Qm{2-0};
   let Inst{0} = bit_0;
 }
 
-multiclass MVE_VMLAMLSDAV_X<string iname, string suffix, dag iops, string cstr,
-                          bit sz, bit bit_28, bit A, bit bit_8, bit bit_0,
+multiclass MVE_VMLAMLSDAV_A<string iname, string x, string suffix,
+                            bit sz, bit bit_28, bit X, bit bit_8, bit bit_0,
                             list<dag> pattern=[]> {
-  def _noexch : MVE_VMLAMLSDAV<iname, suffix, iops, cstr, sz,
-                            bit_28, A, 0b0, bit_8, bit_0, pattern>;
-  def _exch   : MVE_VMLAMLSDAV<iname # "x", suffix, iops, cstr, sz,
-                            bit_28, A, 0b1, bit_8, bit_0, pattern>;
+  def ""#x#suffix : MVE_VMLAMLSDAV<iname # x, suffix,
+                                   (ins MQPR:$Qn, MQPR:$Qm), "",
+                                   sz, bit_28, 0b0, X, bit_8, bit_0, pattern>;
+  def "a"#x#suffix : MVE_VMLAMLSDAV<iname # "a" # x, suffix,
+                                    (ins tGPREven:$RdaSrc, MQPR:$Qn, MQPR:$Qm),
+                                    "$RdaDest = $RdaSrc",
+                                    sz, bit_28, 0b1, X, bit_8, bit_0, pattern>;
 }
 
-multiclass MVE_VMLAMLSDAV_XA<string iname, string suffix, bit sz, bit bit_28,
+multiclass MVE_VMLAMLSDAV_AX<string iname, string suffix, bit sz, bit bit_28,
                              bit bit_8, bit bit_0, list<dag> pattern=[]> {
-  defm _noacc : MVE_VMLAMLSDAV_X<iname, suffix, (ins MQPR:$Qn, MQPR:$Qm), "",
-                              sz, bit_28, 0b0, bit_8, bit_0, pattern>;
-  defm _acc   : MVE_VMLAMLSDAV_X<iname # "a", suffix,
-                             (ins tGPREven:$RdaSrc, MQPR:$Qn, MQPR:$Qm),
-                             "$RdaDest = $RdaSrc",
-                              sz, bit_28, 0b1, bit_8, bit_0, pattern>;
+  defm "" : MVE_VMLAMLSDAV_A<iname, "", suffix, sz, bit_28,
+                             0b0, bit_8, bit_0, pattern>;
+  defm "" : MVE_VMLAMLSDAV_A<iname, "x", suffix, sz, bit_28,
+                             0b1, bit_8, bit_0, pattern>;
+}
+
+multiclass MVE_VMLADAV_multi<string suffix, bit sz, bit bit_8,
+                             list<dag> pattern=[]> {
+  defm "" : MVE_VMLAMLSDAV_AX<"vmladav", "s"#suffix,
+                              sz, 0b0, bit_8, 0b0, pattern>;
+  defm "" : MVE_VMLAMLSDAV_A<"vmladav", "", "u"#suffix,
+                             sz, 0b1, 0b0, bit_8, 0b0, pattern>;
 }
 
-multiclass MVE_VMLADAV_multi<string suffix, bit sz, bit U, bit bit_8,
+multiclass MVE_VMLSDAV_multi<string suffix, bit sz, bit bit_28,
                              list<dag> pattern=[]> {
-  defm "" : MVE_VMLAMLSDAV_XA<"vmladav", suffix, sz, U, bit_8, 0b0, pattern>;
+  defm "" : MVE_VMLAMLSDAV_AX<"vmlsdav", "s"#suffix,
+                              sz, bit_28, 0b0, 0b1, pattern>;
 }
 
-defm MVE_VMLADAVs16 : MVE_VMLADAV_multi<"s16", 0b0, 0b0, 0b0>;
-defm MVE_VMLADAVs32 : MVE_VMLADAV_multi<"s32", 0b1, 0b0, 0b0>;
-defm MVE_VMLADAVu16 : MVE_VMLADAV_multi<"u16", 0b0, 0b1, 0b0>;
-defm MVE_VMLADAVu32 : MVE_VMLADAV_multi<"u32", 0b1, 0b1, 0b0>;
+defm MVE_VMLADAV : MVE_VMLADAV_multi< "8", 0b0, 0b1>;
+defm MVE_VMLADAV : MVE_VMLADAV_multi<"16", 0b0, 0b0>;
+defm MVE_VMLADAV : MVE_VMLADAV_multi<"32", 0b1, 0b0>;
 
-defm MVE_VMLADAVs8 : MVE_VMLADAV_multi<"s8", 0b0, 0b0, 0b1>;
-defm MVE_VMLADAVu8 : MVE_VMLADAV_multi<"u8", 0b0, 0b1, 0b1>;
+defm MVE_VMLSDAV : MVE_VMLSDAV_multi< "8", 0b0, 0b1>;
+defm MVE_VMLSDAV : MVE_VMLSDAV_multi<"16", 0b0, 0b0>;
+defm MVE_VMLSDAV : MVE_VMLSDAV_multi<"32", 0b1, 0b0>;
 
 // vmlav aliases vmladav
-foreach acc = ["_acc", "_noacc"] in {
+foreach acc = ["", "a"] in {
   foreach suffix = ["s8", "s16", "s32", "u8", "u16", "u32"] in {
-    def : MVEInstAlias<!strconcat("vmlav", !if(!eq(acc, "_acc"), "a", ""),
-                       "${vp}.", suffix, "\t$RdaDest, $Qn, $Qm"),
-                       (!cast<Instruction>("MVE_VMLADAV"#suffix#acc#"_noexch")
+    def : MVEInstAlias<"vmlav"#acc#"${vp}."#suffix#"\t$RdaDest, $Qn, $Qm",
+                       (!cast<Instruction>("MVE_VMLADAV"#acc#suffix)
                         tGPREven:$RdaDest, MQPR:$Qn, MQPR:$Qm, vpred_n:$vp)>;
   }
 }
 
-multiclass MVE_VMLSDAV_multi<string suffix, bit sz, bit bit_28,
-                           list<dag> pattern=[]> {
-  defm "" : MVE_VMLAMLSDAV_XA<"vmlsdav", suffix, sz, bit_28, 0b0, 0b1, pattern>;
-}
-
-defm MVE_VMLSDAVs8  : MVE_VMLSDAV_multi<"s8", 0, 0b1>;
-defm MVE_VMLSDAVs16 : MVE_VMLSDAV_multi<"s16", 0, 0b0>;
-defm MVE_VMLSDAVs32 : MVE_VMLSDAV_multi<"s32", 1, 0b0>;
-
 // Base class for VMLALDAV and VMLSLDAV, VRMLALDAVH, VRMLSLDAVH
 class MVE_VMLALDAVBase<string iname, string suffix, dag iops, string cstr,
                        bit sz, bit bit_28, bit A, bit X, bit bit_8, bit bit_0,
                        list<dag> pattern=[]>
   : MVE_rDest<(outs tGPREven:$RdaLoDest, tGPROdd:$RdaHiDest), iops, NoItinerary,
               iname, suffix, "$RdaLoDest, $RdaHiDest, $Qn, $Qm", cstr, pattern> {
   bits<4> RdaLoDest;
   bits<4> RdaHiDest;
   bits<3> Qm;
   bits<3> Qn;
 
   let Inst{28} = bit_28;
   let Inst{22-20} = RdaHiDest{3-1};
   let Inst{19-17} = Qn{2-0};
   let Inst{16} = sz;
   let Inst{15-13} = RdaLoDest{3-1};
   let Inst{12} = X;
   let Inst{8} = bit_8;
   let Inst{7-6} = 0b00;
   let Inst{5} = A;
   let Inst{3-1} = Qm{2-0};
   let Inst{0} = bit_0;
 }
 
-multiclass MVE_VMLALDAVBase_X<string iname, string suffix, dag iops,
-                              string cstr, bit sz, bit bit_28, bit A,
-                              bit bit_8, bit bit_0, list<dag> pattern=[]> {
-  def _noexch : MVE_VMLALDAVBase<iname, suffix, iops, cstr, sz,
-                               bit_28, A, 0b0, bit_8, bit_0, pattern>;
-  def _exch   : MVE_VMLALDAVBase<iname # "x", suffix, iops, cstr, sz,
-                               bit_28, A, 0b1, bit_8, bit_0, pattern>;
+multiclass MVE_VMLALDAVBase_A<string iname, string x, string suffix,
+                               bit sz, bit bit_28, bit X, bit bit_8, bit bit_0,
+                               list<dag> pattern=[]> {
+  def ""#x#suffix : MVE_VMLALDAVBase<
+     iname # x, suffix, (ins MQPR:$Qn, MQPR:$Qm), "",
+     sz, bit_28, 0b0, X, bit_8, bit_0, pattern>;
+  def "a"#x#suffix : MVE_VMLALDAVBase<
+     iname # "a" # x, suffix,
+     (ins tGPREven:$RdaLoSrc, tGPROdd:$RdaHiSrc, MQPR:$Qn, MQPR:$Qm),
+     "$RdaLoDest = $RdaLoSrc,$RdaHiDest = $RdaHiSrc",
+     sz, bit_28, 0b1, X, bit_8, bit_0, pattern>;
 }
 
-multiclass MVE_VMLALDAVBase_XA<string iname, string suffix, bit sz, bit bit_28,
+
+multiclass MVE_VMLALDAVBase_AX<string iname, string suffix, bit sz, bit bit_28,
                                bit bit_8, bit bit_0, list<dag> pattern=[]> {
-  defm _noacc : MVE_VMLALDAVBase_X<
-     iname, suffix, (ins MQPR:$Qn, MQPR:$Qm), "",
-     sz, bit_28, 0b0, bit_8, bit_0, pattern>;
-  defm _acc   : MVE_VMLALDAVBase_X<
-     iname # "a", suffix, (ins tGPREven:$RdaLoSrc, tGPROdd:$RdaHiSrc,
-                               MQPR:$Qn, MQPR:$Qm),
-     "$RdaLoDest = $RdaLoSrc,$RdaHiDest = $RdaHiSrc",
-     sz, bit_28, 0b1, bit_8, bit_0, pattern>;
+  defm "" : MVE_VMLALDAVBase_A<iname, "", suffix, sz,
+                               bit_28, 0b0, bit_8, bit_0, pattern>;
+  defm "" : MVE_VMLALDAVBase_A<iname, "x", suffix, sz,
+                               bit_28, 0b1, bit_8, bit_0, pattern>;
 }
 
-multiclass MVE_VRMLALDAVH_multi<string suffix, bit U, list<dag> pattern=[]> {
-  defm "" : MVE_VMLALDAVBase_XA<
-     "vrmlaldavh", suffix, 0b0, U, 0b1, 0b0, pattern>;
+multiclass MVE_VRMLALDAVH_multi<string suffix, list<dag> pattern=[]> {
+  defm "" : MVE_VMLALDAVBase_AX<"vrmlaldavh", "s"#suffix,
+                                0b0, 0b0, 0b1, 0b0, pattern>;
+  defm "" : MVE_VMLALDAVBase_A<"vrmlaldavh", "", "u"#suffix,
+                               0b0, 0b1, 0b0, 0b1, 0b0, pattern>;
 }
 
-defm MVE_VRMLALDAVHs32 : MVE_VRMLALDAVH_multi<"s32", 0>;
-defm MVE_VRMLALDAVHu32 : MVE_VRMLALDAVH_multi<"u32", 1>;
+defm MVE_VRMLALDAVH : MVE_VRMLALDAVH_multi<"32">;
 
 // vrmlalvh aliases for vrmlaldavh
 def : MVEInstAlias<"vrmlalvh${vp}.s32\t$RdaLo, $RdaHi, $Qn, $Qm",
-                  (MVE_VRMLALDAVHs32_noacc_noexch
+                  (MVE_VRMLALDAVHs32
                    tGPREven:$RdaLo, tGPROdd:$RdaHi,
                    MQPR:$Qn, MQPR:$Qm, vpred_n:$vp)>;
 def : MVEInstAlias<"vrmlalvha${vp}.s32\t$RdaLo, $RdaHi, $Qn, $Qm",
-                  (MVE_VRMLALDAVHs32_acc_noexch
+                  (MVE_VRMLALDAVHas32
                    tGPREven:$RdaLo, tGPROdd:$RdaHi,
                    MQPR:$Qn, MQPR:$Qm, vpred_n:$vp)>;
 def : MVEInstAlias<"vrmlalvh${vp}.u32\t$RdaLo, $RdaHi, $Qn, $Qm",
-                  (MVE_VRMLALDAVHu32_noacc_noexch
+                  (MVE_VRMLALDAVHu32
                    tGPREven:$RdaLo, tGPROdd:$RdaHi,
                    MQPR:$Qn, MQPR:$Qm, vpred_n:$vp)>;
 def : MVEInstAlias<"vrmlalvha${vp}.u32\t$RdaLo, $RdaHi, $Qn, $Qm",
-                  (MVE_VRMLALDAVHu32_acc_noexch
+                  (MVE_VRMLALDAVHau32
                    tGPREven:$RdaLo, tGPROdd:$RdaHi,
                    MQPR:$Qn, MQPR:$Qm, vpred_n:$vp)>;
 
-multiclass MVE_VMLALDAV_multi<string suffix, bit sz, bit U,
-                              list<dag> pattern=[]> {
-  defm "" : MVE_VMLALDAVBase_XA<"vmlaldav", suffix, sz, U, 0b0, 0b0, pattern>;
+multiclass MVE_VMLALDAV_multi<string suffix, bit sz, list<dag> pattern=[]> {
+  defm "" : MVE_VMLALDAVBase_AX<"vmlaldav", "s"#suffix, sz, 0b0, 0b0, 0b0, pattern>;
+  defm "" : MVE_VMLALDAVBase_A<"vmlaldav", "", "u"#suffix,
+                               sz, 0b1, 0b0, 0b0, 0b0, pattern>;
 }
 
-defm MVE_VMLALDAVs16 : MVE_VMLALDAV_multi<"s16", 0b0, 0b0>;
-defm MVE_VMLALDAVs32 : MVE_VMLALDAV_multi<"s32", 0b1, 0b0>;
-defm MVE_VMLALDAVu16 : MVE_VMLALDAV_multi<"u16", 0b0, 0b1>;
-defm MVE_VMLALDAVu32 : MVE_VMLALDAV_multi<"u32", 0b1, 0b1>;
+defm MVE_VMLALDAV : MVE_VMLALDAV_multi<"16", 0b0>;
+defm MVE_VMLALDAV : MVE_VMLALDAV_multi<"32", 0b1>;
 
 // vmlalv aliases vmlaldav
-foreach acc = ["_acc", "_noacc"] in {
+foreach acc = ["", "a"] in {
   foreach suffix = ["s16", "s32", "u16", "u32"] in {
-    def : MVEInstAlias<!strconcat("vmlalv", !if(!eq(acc, "_acc"), "a", ""),
-                       "${vp}.", suffix, "\t$RdaLoDest, $RdaHiDest, $Qn, $Qm"),
-                       (!cast<Instruction>("MVE_VMLALDAV"#suffix#acc#"_noexch")
+    def : MVEInstAlias<"vmlalv" # acc # "${vp}." # suffix #
+                          "\t$RdaLoDest, $RdaHiDest, $Qn, $Qm",
+                       (!cast<Instruction>("MVE_VMLALDAV"#acc#suffix)
                        tGPREven:$RdaLoDest, tGPROdd:$RdaHiDest,
                        MQPR:$Qn, MQPR:$Qm, vpred_n:$vp)>;
   }
 }
 
 multiclass MVE_VMLSLDAV_multi<string iname, string suffix, bit sz,
                               bit bit_28, list<dag> pattern=[]> {
-  defm "" : MVE_VMLALDAVBase_XA<iname, suffix, sz, bit_28, 0b0, 0b1, pattern>;
+  defm "" : MVE_VMLALDAVBase_AX<iname, suffix, sz, bit_28, 0b0, 0b1, pattern>;
 }
 
-defm MVE_VMLSLDAVs16   : MVE_VMLSLDAV_multi<"vmlsldav", "s16", 0b0, 0b0>;
-defm MVE_VMLSLDAVs32   : MVE_VMLSLDAV_multi<"vmlsldav", "s32", 0b1, 0b0>;
-defm MVE_VRMLSLDAVHs32 : MVE_VMLSLDAV_multi<"vrmlsldavh", "s32", 0b0, 0b1>;
+defm MVE_VMLSLDAV   : MVE_VMLSLDAV_multi<"vmlsldav", "s16", 0b0, 0b0>;
+defm MVE_VMLSLDAV   : MVE_VMLSLDAV_multi<"vmlsldav", "s32", 0b1, 0b0>;
+defm MVE_VRMLSLDAVH : MVE_VMLSLDAV_multi<"vrmlsldavh", "s32", 0b0, 0b1>;
 
 // end of mve_rDest instructions
 
 // start of mve_comp instructions
 
 class MVE_comp<InstrItinClass itin, string iname, string suffix,
                string cstr, list<dag> pattern=[]>
   : MVE_p<(outs MQPR:$Qd), (ins MQPR:$Qn, MQPR:$Qm), itin, iname, suffix,

llvm/trunk/test/MC/ARM/mve-reductions.s

 vmladava.s16 lr, q0, q4
 
 # CHECK: vmladavx.s16 r0, q0, q7  @ encoding: [0xf0,0xee,0x0e,0x1e]
 vmladavx.s16 r0, q0, q7
 
 # CHECK: vmladavax.s16 lr, q0, q7  @ encoding: [0xf0,0xee,0x2e,0xfe]
 vmladavax.s16 lr, q0, q7
 
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vmladavax.u16 r0, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vmladavx.u16 r0, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vmladavax.u32 r0, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vmladavx.u32 r0, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vmladavax.u8 r0, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vmladavx.u8 r0, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vmlaldavax.u16 r2, r3, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vmlaldavx.u16 r2, r3, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vmlaldavax.u32 r2, r3, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vmlaldavx.u32 r2, r3, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vrmlaldavhax.u32 r2, r3, q4, q5
+
+# ERROR: [[@LINE+1]]:{{[0-9]+}}: {{error|note}}: invalid operand for instruction
+vrmlaldavhx.u32 r2, r3, q4, q5
+
 # CHECK: vmlav.s8 lr, q3, q0  @ encoding: [0xf6,0xee,0x00,0xef]
 vmladav.s8 lr, q3, q0
 
 # CHECK: vmlav.u8 lr, q1, q7  @ encoding: [0xf2,0xfe,0x0e,0xef]
 vmladav.u8 lr, q1, q7
 
 # CHECK: vrmlalvh.s32 lr, r1, q6, q2  @ encoding: [0x8c,0xee,0x04,0xef]
 vrmlaldavh.s32 lr, r1, q6, q2

llvm/trunk/test/MC/Disassembler/ARM/mve-reductions.txt

-# RUN: llvm-mc -disassemble -triple=thumbv8.1m.main-none-eabi -mattr=+mve.fp,+fp64 -show-encoding %s | FileCheck %s
+# RUN: not llvm-mc -disassemble -triple=thumbv8.1m.main-none-eabi -mattr=+mve.fp,+fp64 -show-encoding %s 2> %t | FileCheck %s
+# RUN: FileCheck --check-prefix=ERROR < %t %s
 # RUN: not llvm-mc -disassemble -triple=thumbv8.1m.main-none-eabi -show-encoding %s &> %t
 # RUN: FileCheck --check-prefix=CHECK-NOMVE < %t %s
 
 [0x82 0xee 0x07 0x0f]
 # CHECK: vabav.s8  r0, q1, q3
 # CHECK-NOMVE: [[@LINE-2]]:2: warning: invalid instruction encoding
 
 [0x92 0xee 0x07 0x0f]

 # CHECK: vmladavx.s16 r0, q0, q7  @ encoding: [0xf0,0xee,0x0e,0x1e]
 # CHECK-NOMVE: [[@LINE+1]]:2: warning: invalid instruction encoding
 [0xf0,0xee,0x0e,0x1e]
 
 # CHECK: vmladavax.s16 lr, q0, q7  @ encoding: [0xf0,0xee,0x2e,0xfe]
 # CHECK-NOMVE: [[@LINE+1]]:2: warning: invalid instruction encoding
 [0xf0,0xee,0x2e,0xfe]
 
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0xf8,0xfe,0x2a,0x1e]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0xf8,0xfe,0x0a,0x1e]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0xf9,0xfe,0x2a,0x1e]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0xf9,0xfe,0x0a,0x1e]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0xf8,0xfe,0x2a,0x1f]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0xf8,0xfe,0x0a,0x1f]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0x98,0xfe,0x2a,0x3e]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0x98,0xfe,0x0a,0x3e]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0x99,0xfe,0x2a,0x3e]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0x99,0xfe,0x0a,0x3e]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0x98,0xfe,0x2a,0x3f]
+
+# ERROR: [[@LINE+1]]:2: warning: invalid instruction encoding
+[0x98,0xfe,0x0a,0x3f]
+
 # CHECK: vmlav.s8 lr, q3, q0  @ encoding: [0xf6,0xee,0x00,0xef]
 # CHECK-NOMVE: [[@LINE+1]]:2: warning: invalid instruction encoding
 [0xf6,0xee,0x00,0xef]
 
 # CHECK: vmlav.u8 lr, q1, q7  @ encoding: [0xf2,0xfe,0x0e,0xef]
 # CHECK-NOMVE: [[@LINE+1]]:2: warning: invalid instruction encoding
 [0xf2,0xfe,0x0e,0xef]