diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -10090,13 +10090,11 @@
   case MVT::i1: {
     // The only legal i1 vectors are SVE vectors, so we can use SVE-specific
     // lowering code.
-    if (auto *ConstVal = dyn_cast<ConstantSDNode>(SplatVal)) {
-      // We can hande the zero case during isel.
-      if (ConstVal->isZero())
-        return Op;
-      if (ConstVal->isOne())
-        return getPTrue(DAG, dl, VT, AArch64SVEPredPattern::all);
-    }
+
+    // We can handle the constant cases during isel.
+    if (isa<ConstantSDNode>(SplatVal))
+      return Op;
+
     // The general case of i1.  There isn't any natural way to do this,
     // so we use some trickery with whilelo.
     SplatVal = DAG.getAnyExtOrTrunc(SplatVal, dl, MVT::i64);
@@ -15361,6 +15359,9 @@
       return false;
   }
 
+  if (ISD::isConstantSplatVectorAllOnes(N.getNode()))
+    return true;
+
   // "ptrue p.<ty>, all" can be considered all active when <ty> is the same size
   // or smaller than the implicit element type represented by N.
   // NOTE: A larger element count implies a smaller element type.
diff --git a/llvm/lib/Target/AArch64/SVEInstrFormats.td b/llvm/lib/Target/AArch64/SVEInstrFormats.td
--- a/llvm/lib/Target/AArch64/SVEInstrFormats.td
+++ b/llvm/lib/Target/AArch64/SVEInstrFormats.td
@@ -338,6 +338,11 @@
 let Predicates = [HasSVEorStreamingSVE] in {
   defm PTRUE  : sve_int_ptrue<0b000, "ptrue", AArch64ptrue>;
   defm PTRUES : sve_int_ptrue<0b001, "ptrues", null_frag>;
+
+  def : Pat<(nxv16i1 immAllOnesV), (PTRUE_B 31)>;
+  def : Pat<(nxv8i1 immAllOnesV), (PTRUE_H 31)>;
+  def : Pat<(nxv4i1 immAllOnesV), (PTRUE_S 31)>;
+  def : Pat<(nxv2i1 immAllOnesV), (PTRUE_D 31)>;
 }
 
 //===----------------------------------------------------------------------===//
@@ -638,10 +643,10 @@
 multiclass sve_int_pfalse<bits<6> opc, string asm> {
   def NAME : sve_int_pfalse<opc, asm>;
 
-  def : Pat<(nxv16i1 (splat_vector (i32 0))), (!cast<Instruction>(NAME))>;
-  def : Pat<(nxv8i1 (splat_vector (i32 0))), (!cast<Instruction>(NAME))>;
-  def : Pat<(nxv4i1 (splat_vector (i32 0))), (!cast<Instruction>(NAME))>;
-  def : Pat<(nxv2i1 (splat_vector (i32 0))), (!cast<Instruction>(NAME))>;
+  def : Pat<(nxv16i1 immAllZerosV), (!cast<Instruction>(NAME))>;
+  def : Pat<(nxv8i1 immAllZerosV), (!cast<Instruction>(NAME))>;
+  def : Pat<(nxv4i1 immAllZerosV), (!cast<Instruction>(NAME))>;
+  def : Pat<(nxv2i1 immAllZerosV), (!cast<Instruction>(NAME))>;
 }
 
 class sve_int_ptest<bits<6> opc, string asm>