[PATCH] D52829: [AArch64] Fix verifier error when outlining indirect calls

[Oliver Stannard via Phabricator via llvm-commits]

olista01 created this revision.
olista01 added a reviewer: jpaquette.
Herald added a reviewer: javed.absar.
Herald added a subscriber: kristof.beyls.

The MachineOutliner for AArch64 transforms indirect calls into indirect
tail calls, replacing the call with the TCRETURNri pseudo-instruction.
This pseudo lowers to a BR, but has the isCall and isReturn flags set.

The problem is that TCRETURNri takes a tcGPR64 as the register argument,
to prevent indiret tail-calls from using caller-saved registers. The
indirect calls transformed by the outliner could use caller-saved
registers.  This is fine, because the outliner ensures that the register
is available at all call sites. However, this causes a verifier failure
when the register is not in tcGPR64. The fix is to add a new
pseudo-instruction like TCRETURNri, but which accepts any GPR.


Repository:
  rL LLVM

https://reviews.llvm.org/D52829

Files:
  lib/Target/AArch64/AArch64AsmPrinter.cpp
  lib/Target/AArch64/AArch64InstrInfo.cpp
  lib/Target/AArch64/AArch64InstrInfo.td
  test/CodeGen/AArch64/machine-outliner-thunk.ll

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