[ARM][MVE] Enable *SHRN* for tail predication

These instructions don't swap lanes so make them valid.

Differential Revision: https://reviews.llvm.org/D75667

Author: sparker-arm

llvm/lib/Target/ARM/ARMInstrMVE.td

@@ -2649,6 +2649,7 @@ class MVE_VxSHRN<string iname, string suffix, bit bit_12, bit bit_28,
   let Inst{11-6} = 0b111111;
   let Inst{4} = 0b0;
   let Inst{0} = 0b1;
+  let validForTailPredication = 1;
 }
 
 def MVE_VRSHRNi16bh : MVE_VxSHRN<"vrshrnb", "i16", 0b0, 0b1, shr_imm8> {
@@ -2690,6 +2691,7 @@ class MVE_VxQRSHRUN<string iname, string suffix, bit bit_28, bit bit_12,
   let Inst{11-6} = 0b111111;
   let Inst{4} = 0b0;
   let Inst{0} = 0b0;
+  let validForTailPredication = 1;
 }
 
 def MVE_VQRSHRUNs16bh : MVE_VxQRSHRUN<
@@ -2738,6 +2740,7 @@ class MVE_VxQRSHRN<string iname, string suffix, bit bit_0, bit bit_12,
   let Inst{11-6} = 0b111101;
   let Inst{4} = 0b0;
   let Inst{0} = bit_0;
+  let validForTailPredication = 1;
 }
 
 multiclass MVE_VxQRSHRN_types<string iname, bit bit_0, bit bit_12> {

llvm/unittests/Target/ARM/MachineInstrTest.cpp

@@ -354,6 +354,30 @@ TEST(MachineInstrValidTailPredication, IsCorrect) {
     case MVE_VQSHL_qru16:
     case MVE_VQSHL_qru32:
     case MVE_VQSHL_qru8:
+    case MVE_VQRSHRNbhs16:
+    case MVE_VQRSHRNbhs32:
+    case MVE_VQRSHRNbhu16:
+    case MVE_VQRSHRNbhu32:
+    case MVE_VQRSHRNths16:
+    case MVE_VQRSHRNths32:
+    case MVE_VQRSHRNthu16:
+    case MVE_VQRSHRNthu32:
+    case MVE_VQRSHRUNs16bh:
+    case MVE_VQRSHRUNs16th:
+    case MVE_VQRSHRUNs32bh:
+    case MVE_VQRSHRUNs32th:
+    case MVE_VQSHRNbhs16:
+    case MVE_VQSHRNbhs32:
+    case MVE_VQSHRNbhu16:
+    case MVE_VQSHRNbhu32:
+    case MVE_VQSHRNths16:
+    case MVE_VQSHRNths32:
+    case MVE_VQSHRNthu16:
+    case MVE_VQSHRNthu32:
+    case MVE_VQSHRUNs16bh:
+    case MVE_VQSHRUNs16th:
+    case MVE_VQSHRUNs32bh:
+    case MVE_VQSHRUNs32th:
     case MVE_VQSUB_qr_s16:
     case MVE_VQSUB_qr_s32:
     case MVE_VQSUB_qr_s8:
@@ -402,6 +426,10 @@ TEST(MachineInstrValidTailPredication, IsCorrect) {
     case MVE_VRSHR_immu16:
     case MVE_VRSHR_immu32:
     case MVE_VRSHR_immu8:
+    case MVE_VRSHRNi16bh:
+    case MVE_VRSHRNi16th:
+    case MVE_VRSHRNi32bh:
+    case MVE_VRSHRNi32th:
     case MVE_VSHL_by_vecs16:
     case MVE_VSHL_by_vecs32:
     case MVE_VSHL_by_vecs8:
@@ -423,6 +451,10 @@ TEST(MachineInstrValidTailPredication, IsCorrect) {
     case MVE_VSHR_immu16:
     case MVE_VSHR_immu32:
     case MVE_VSHR_immu8:
+    case MVE_VSHRNi16bh:
+    case MVE_VSHRNi16th:
+    case MVE_VSHRNi32bh:
+    case MVE_VSHRNi32th:
     case MVE_VSLIimm16:
     case MVE_VSLIimm32:
     case MVE_VSLIimm8: