[all-commits] [llvm/llvm-project] 861241: [DebugInfo][InstrRef] Don't break up ret-sequences...

[Jeremy Morse via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8612417e5a54cfef941ab45de55e48b4a0c4e8b4
      https://github.com/llvm/llvm-project/commit/8612417e5a54cfef941ab45de55e48b4a0c4e8b4
  Author: Jeremy Morse <jeremy.morse at sony.com>
  Date:   2021-07-28 (Wed, 28 Jul 2021)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
    A llvm/test/DebugInfo/ARM/instr-ref-tcreturn.ll

  Log Message:
  -----------
  [DebugInfo][InstrRef] Don't break up ret-sequences on debug-info instrs

When we have a terminator sequence (i.e. a tailcall or return),
MIIsInTerminatorSequence is used to work out where the preceding ABI-setup
instructions end, i.e. the parts that were glued to the terminator
instruction. This allows LLVM to split blocks safely without having to
worry about ABI stuff.

The function only ignores DBG_VALUE instructions, meaning that the two
debug instructions I recently added can end terminator sequences early,
causing various MachineVerifier errors. This patch promotes the test for
debug instructions from "isDebugValue" to "isDebugInstr", thus avoiding any
debug-info interfering with this function.

Differential Revision: https://reviews.llvm.org/D106660