[AArch64] Add PMOV aliases with implicit portion index (#76056)

In the latest ISA update the syntax of the PMOV instructions was updated
to allow the portion index to be optional, default to zero.

https://developer.arm.com/documentation/ddi0602/2023-09/SVE-Instructions/PMOV--to-predicate---Move-predicate-from-vector-?lang=en

https://developer.arm.com/documentation/ddi0602/2023-09/SVE-Instructions/PMOV--to-vector---Move-predicate-to-vector-?lang=en

Author: momchil-velikov

llvm/lib/Target/AArch64/SVEInstrFormats.td

@@ -10082,6 +10082,12 @@ multiclass sve2p1_vector_to_pred<string mnemonic, SDPatternOperator Op_lane, SDP
 
   def : InstAlias<mnemonic # "\t$Pd, $Zn",
                  (!cast<Instruction>(NAME # _B) PPR8:$Pd, ZPRAny:$Zn, 0), 1>;
+  def : InstAlias<mnemonic # "\t$Pd, $Zn",
+                 (!cast<Instruction>(NAME # _H) PPR16:$Pd, ZPRAny:$Zn, 0), 0>;
+  def : InstAlias<mnemonic # "\t$Pd, $Zn",
+                 (!cast<Instruction>(NAME # _S) PPR32:$Pd, ZPRAny:$Zn, 0), 0>;
+  def : InstAlias<mnemonic # "\t$Pd, $Zn",
+                 (!cast<Instruction>(NAME # _D) PPR64:$Pd, ZPRAny:$Zn, 0), 0>;
 
   // any_lane
   def : Pat<(nxv16i1 (Op_lane (nxv16i8 ZPRAny:$Zn), (i32 timm32_0_0:$Idx))),
@@ -10143,6 +10149,12 @@ multiclass sve2p1_pred_to_vector<string mnemonic, SDPatternOperator MergeOp,
 
   def : InstAlias<mnemonic # "\t$Zd, $Pn",
                  (!cast<Instruction>(NAME # _B) ZPRAny:$Zd, 0, PPR8:$Pn), 1>;
+  def : InstAlias<mnemonic # "\t$Zd, $Pn",
+                 (!cast<Instruction>(NAME # _H) ZPRAny:$Zd, 0, PPR16:$Pn), 0>;
+  def : InstAlias<mnemonic # "\t$Zd, $Pn",
+                 (!cast<Instruction>(NAME # _S) ZPRAny:$Zd, 0, PPR32:$Pn), 0>;
+  def : InstAlias<mnemonic # "\t$Zd, $Pn",
+                 (!cast<Instruction>(NAME # _D) ZPRAny:$Zd, 0, PPR64:$Pn), 0>;
 
   // Merge
   def : Pat<(nxv8i16 (MergeOp (nxv8i16 ZPRAny:$Zd), (nxv8i1 PPR16:$Pn), (i32 timm32_1_1:$Idx))),

llvm/test/MC/AArch64/SVE2p1/pmov.s

@@ -20,6 +20,12 @@ pmov    p0.h, z0[0]  // 00000101-00101100-00111000-00000000
 // CHECK-ERROR: instruction requires: sme2p1 or sve2p1
 // CHECK-UNKNOWN: 052c3800 <unknown>
 
+pmov    p0.h, z0  // 00000101-00101100-00111000-00000000
+// CHECK-INST: pmov    p0.h, z0[0]
+// CHECK-ENCODING: [0x00,0x38,0x2c,0x05]
+// CHECK-ERROR: instruction requires: sme2p1 or sve2p1
+// CHECK-UNKNOWN: 052c3800 <unknown>
+
 pmov    p5.h, z10[0]  // 00000101-00101100-00111001-01000101
 // CHECK-INST: pmov    p5.h, z10[0]
 // CHECK-ENCODING: [0x45,0x39,0x2c,0x05]
@@ -44,6 +50,12 @@ pmov    p0.s, z0[0]  // 00000101-01101000-00111000-00000000
 // CHECK-ERROR: instruction requires: sme2p1 or sve2p1
 // CHECK-UNKNOWN: 05683800 <unknown>
 
+pmov    p0.s, z0  // 00000101-01101000-00111000-00000000
+// CHECK-INST: pmov    p0.s, z0[0]
+// CHECK-ENCODING: [0x00,0x38,0x68,0x05]
+// CHECK-ERROR: instruction requires: sme2p1 or sve2p1
+// CHECK-UNKNOWN: 05683800 <unknown>
+
 pmov    p5.s, z10[2]  // 00000101-01101100-00111001-01000101
 // CHECK-INST: pmov    p5.s, z10[2]
 // CHECK-ENCODING: [0x45,0x39,0x6c,0x05]
@@ -68,6 +80,12 @@ pmov    p0.d, z0[0]  // 00000101-10101000-00111000-00000000
 // CHECK-ERROR: instruction requires: sme2p1 or sve2p1
 // CHECK-UNKNOWN: 05a83800 <unknown>
 
+pmov    p0.d, z0  // 00000101-10101000-00111000-00000000
+// CHECK-INST: pmov    p0.d, z0[0]
+// CHECK-ENCODING: [0x00,0x38,0xa8,0x05]
+// CHECK-ERROR: instruction requires: sme2p1 or sve2p1
+// CHECK-UNKNOWN: 05a83800 <unknown>
+
 pmov    p5.d, z10[6]  // 00000101-11101100-00111001-01000101
 // CHECK-INST: pmov    p5.d, z10[6]
 // CHECK-ENCODING: [0x45,0x39,0xec,0x05]
@@ -122,6 +140,12 @@ pmov    z0[0], p0.h  // 00000101-00101101-00111000-00000000
 // CHECK-ERROR: instruction requires: sme2p1 or sve2p1
 // CHECK-UNKNOWN: 052d3800 <unknown>
 
+pmov    z0, p0.h  // 00000101-00101101-00111000-00000000
+// CHECK-INST: pmov    z0[0], p0.h
+// CHECK-ENCODING: [0x00,0x38,0x2d,0x05]
+// CHECK-ERROR: instruction requires: sme2p1 or sve2p1
+// CHECK-UNKNOWN: 052d3800 <unknown>
+
 pmov    z21[0], p10.h  // 00000101-00101101-00111001-01010101
 // CHECK-INST: pmov    z21[0], p10.h
 // CHECK-ENCODING: [0x55,0x39,0x2d,0x05]
@@ -147,6 +171,12 @@ pmov    z0[0], p0.s  // 00000101-01101001-00111000-00000000
 // CHECK-ERROR: instruction requires: sme2p1 or sve2p1
 // CHECK-UNKNOWN: 05693800 <unknown>
 
+pmov    z0, p0.s  // 00000101-01101001-00111000-00000000
+// CHECK-INST: pmov    z0[0], p0.s
+// CHECK-ENCODING: [0x00,0x38,0x69,0x05]
+// CHECK-ERROR: instruction requires: sme2p1 or sve2p1
+// CHECK-UNKNOWN: 05693800 <unknown>
+
 pmov    z21[2], p10.s  // 00000101-01101101-00111001-01010101
 // CHECK-INST: pmov    z21[2], p10.s
 // CHECK-ENCODING: [0x55,0x39,0x6d,0x05]
@@ -171,6 +201,12 @@ pmov    z0[0], p0.d  // 00000101-10101001-00111000-00000000
 // CHECK-ERROR: instruction requires: sme2p1 or sve2p1
 // CHECK-UNKNOWN: 05a93800 <unknown>
 
+pmov    z0, p0.d  // 00000101-10101001-00111000-00000000
+// CHECK-INST: pmov    z0[0], p0.d
+// CHECK-ENCODING: [0x00,0x38,0xa9,0x05]
+// CHECK-ERROR: instruction requires: sme2p1 or sve2p1
+// CHECK-UNKNOWN: 05a93800 <unknown>
+
 pmov    z21[6], p10.d  // 00000101-11101101-00111001-01010101
 // CHECK-INST: pmov    z21[6], p10.d
 // CHECK-ENCODING: [0x55,0x39,0xed,0x05]