[llvm-branch-commits] [llvm] [AArch64][PAC] Lower authenticated calls with ptrauth bundles. (PR #85736)

[Ahmed Bougacha via llvm-branch-commits]

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@@ -817,10 +817,44 @@ bool AArch64ExpandPseudo::expandCALL_RVMARKER(
   MachineInstr &MI = *MBBI;
   MachineOperand &RVTarget = MI.getOperand(0);
   assert(RVTarget.isGlobal() && "invalid operand for attached call");
-  MachineInstr *OriginalCall =
-      createCall(MBB, MBBI, TII, MI.getOperand(1),
-                 // Regmask starts after the RV and call targets.
-                 /*RegMaskStartIdx=*/2);
+
+  MachineInstr *OriginalCall = nullptr;
+
+  if (MI.getOpcode() == AArch64::BLRA_RVMARKER) {
+    // Pointer auth call.
+    MachineOperand &Key = MI.getOperand(2);
+    assert((Key.getImm() == 0 || Key.getImm() == 1) &&
+           "invalid key for ptrauth call");
+    MachineOperand &IntDisc = MI.getOperand(3);
+    MachineOperand &AddrDisc = MI.getOperand(4);
+
+    OriginalCall = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::BLRA))
+                       .getInstr();
+    OriginalCall->addOperand(MI.getOperand(1));
+    OriginalCall->addOperand(Key);
+    OriginalCall->addOperand(IntDisc);
+    OriginalCall->addOperand(AddrDisc);
+
+    unsigned RegMaskStartIdx = 5;
+    // Skip register arguments. Those are added during ISel, but are not
+    // needed for the concrete branch.
+    while (!MI.getOperand(RegMaskStartIdx).isRegMask()) {
+      auto MOP = MI.getOperand(RegMaskStartIdx);
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ahmedbougacha wrote:

The helper indeed shouldn't use plain auto, but we can reuse that helper with a bit of generalization.  I'm pretty sure this code predates it ;)

https://github.com/llvm/llvm-project/pull/85736