[PATCH] D153320: [XRay][AArch64] Suppport __xray_customevent/__xray_typedevent

[Fangrui Song via Phabricator via llvm-commits]

MaskRay created this revision.
MaskRay added reviewers: danielkiss, dmgreen, efriedma, dberris, peter.smith.
Herald added subscribers: Enna1, hiraditya, kristof.beyls.
Herald added a project: All.
MaskRay requested review of this revision.
Herald added projects: Sanitizers, LLVM.
Herald added subscribers: llvm-commits, Sanitizers.

`__xray_customevent` and `__xray_typedevent` are built-in functions in Clang.
With -fxray-instrument, they are lowered to intrinsics llvm.xray.customevent and
llvm.xray.typedevent, respectively. These intrinsics are then lowered to
TargetOpcode::{PATCHABLE_EVENT_CALL,PATCHABLE_TYPED_EVENT_CALL}. The target is
responsible for generating a code sequence that calls either
`__xray_CustomEvent` (with 2 arguments) or `__xray_TypedEvent` (with 3
arguments).

Before patching, the code sequence is prefixed by a branch instruction that
skips the rest of the code sequence. After patching
(compiler-rt/lib/xray/xray_AArch64.cpp), the branch instruction becomes a NOP
and the function call will take effects.

This patch implements the lowering process for
{PATCHABLE_EVENT_CALL,PATCHABLE_TYPED_EVENT_CALL} and implements the runtime.

  // Lowering of PATCHABLE_EVENT_CALL
  .Lxray_sled_N:
    b  #24
    stp x0, x1, [sp, #-16]!
    x0 = reg of op0
    x1 = reg of op1
    bl __xray_CustomEvent
    ldrp x0, x1, [sp], #16

As a result, two updated tests in compiler-rt/test/xray/TestCases/Posix/ now
pass on AArch64.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D153320

Files:
  compiler-rt/lib/xray/xray_AArch64.cpp
  compiler-rt/lib/xray/xray_trampoline_AArch64.S
  compiler-rt/test/xray/TestCases/Posix/custom-event-logging.cpp
  compiler-rt/test/xray/TestCases/Posix/typed-event-logging.cpp
  llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
  llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
  llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
  llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
  llvm/test/CodeGen/AArch64/xray-custom-log.ll

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