Add test cases to ptrauth-isel.mir & minor comment improvements

Author: atrosinenko

llvm/lib/Target/AArch64/AArch64ISelLowering.h

@@ -183,7 +183,7 @@ class AArch64TargetLowering : public TargetLowering {
                                         MachineBasicBlock *BB) const;
 
   /// Replace (0, vreg) discriminator components with the operands of blend
-  /// or with (immediate, XZR) when possible.
+  /// or with (immediate, NoRegister) when possible.
   void fixupPtrauthDiscriminator(MachineInstr &MI, MachineBasicBlock *BB,
                                  MachineOperand &IntDiscOp,
                                  MachineOperand &AddrDiscOp,

llvm/lib/Target/AArch64/AArch64InstrInfo.td

@@ -2168,6 +2168,7 @@ let Predicates = [HasPAuth] in {
     let usesCustomInserter = 1;
   }
 
+  // A standalone pattern is used, so that literal 0 can be passed as $Disc.
   def : Pat<(int_ptrauth_sign GPR64:$Val, timm:$Key, GPR64noip:$AddrDisc),
             (PAC GPR64:$Val, $Key, 0, GPR64noip:$AddrDisc)>;
 

llvm/test/CodeGen/AArch64/ptrauth-isel.mir

@@ -25,10 +25,25 @@
     ret i64 0
   }
 
+  define i64 @movi64imm_immediate_operand(i64 %a) {
+  entry:
+    ret i64 0
+  }
+
   define i64 @movi64imm_non_immediate_operand(i64 %a) {
   entry:
     ret i64 0
   }
+
+  define i64 @movi32imm_immediate_operand(i64 %a) {
+  entry:
+    ret i64 0
+  }
+
+  define i64 @movi32imm_non_immediate_operand(i64 %a) {
+  entry:
+    ret i64 0
+  }
 ...
 ---
 name:            movk_correct_blend
@@ -101,6 +116,27 @@ body:             |
     RET_ReallyLR implicit $x0
 ...
 ---
+name:            movi64imm_immediate_operand
+tracksRegLiveness: true
+body:             |
+  bb.0.entry:
+    liveins: $x0, $x1
+
+    ; CHECK-LABEL: name: movi64imm_immediate_operand
+    ; CHECK: liveins: $x0, $x1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+    ; CHECK-NEXT: [[MOVi64imm:%[0-9]+]]:gpr64noip = MOVi64imm 42
+    ; CHECK-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 42, killed $noreg, implicit-def dead $x17
+    ; CHECK-NEXT: $x0 = COPY [[PAC]]
+    ; CHECK-NEXT: RET_ReallyLR implicit $x0
+    %0:gpr64 = COPY $x0
+    %1:gpr64noip = MOVi64imm 42
+    %2:gpr64 = PAC %0, 2, 0, killed %1, implicit-def dead $x17
+    $x0 = COPY %2
+    RET_ReallyLR implicit $x0
+...
+---
 name:            movi64imm_non_immediate_operand
 tracksRegLiveness: true
 body:             |
@@ -121,3 +157,49 @@ body:             |
     $x0 = COPY %2
     RET_ReallyLR implicit $x0
 ...
+---
+name:            movi32imm_immediate_operand
+tracksRegLiveness: true
+body:             |
+  bb.0.entry:
+    liveins: $x0, $x1
+
+    ; CHECK-LABEL: name: movi32imm_immediate_operand
+    ; CHECK: liveins: $x0, $x1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+    ; CHECK-NEXT: [[MOVi32imm:%[0-9]+]]:gpr32 = MOVi32imm 42
+    ; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gpr64noip = SUBREG_TO_REG 0, killed [[MOVi32imm]], %subreg.sub_32
+    ; CHECK-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 42, killed $noreg, implicit-def dead $x17
+    ; CHECK-NEXT: $x0 = COPY [[PAC]]
+    ; CHECK-NEXT: RET_ReallyLR implicit $x0
+    %0:gpr64 = COPY $x0
+    %1:gpr32 = MOVi32imm 42
+    %2:gpr64noip = SUBREG_TO_REG 0, killed %1, %subreg.sub_32
+    %3:gpr64 = PAC %0, 2, 0, killed %2, implicit-def dead $x17
+    $x0 = COPY %3
+    RET_ReallyLR implicit $x0
+...
+---
+name:            movi32imm_non_immediate_operand
+tracksRegLiveness: true
+body:             |
+  bb.0.entry:
+    liveins: $x0, $x1
+
+    ; CHECK-LABEL: name: movi32imm_non_immediate_operand
+    ; CHECK: liveins: $x0, $x1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:gpr64 = COPY $x0
+    ; CHECK-NEXT: [[MOVi32imm:%[0-9]+]]:gpr32 = MOVi32imm target-flags(aarch64-pageoff, aarch64-nc) @globalvar
+    ; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gpr64noip = SUBREG_TO_REG 0, killed [[MOVi32imm]], %subreg.sub_32
+    ; CHECK-NEXT: [[PAC:%[0-9]+]]:gpr64 = PAC [[COPY]], 2, 0, killed [[SUBREG_TO_REG]], implicit-def dead $x17
+    ; CHECK-NEXT: $x0 = COPY [[PAC]]
+    ; CHECK-NEXT: RET_ReallyLR implicit $x0
+    %0:gpr64 = COPY $x0
+    %1:gpr32 = MOVi32imm target-flags(aarch64-pageoff, aarch64-nc) @globalvar
+    %2:gpr64noip = SUBREG_TO_REG 0, killed %1, %subreg.sub_32
+    %3:gpr64 = PAC %0, 2, 0, killed %2, implicit-def dead $x17
+    $x0 = COPY %3
+    RET_ReallyLR implicit $x0
+...