[all-commits] [llvm/llvm-project] ab86ed: [AArch64] Implement __rndr, __rndrrs intrinsics

[Stelios Ioannou via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: ab86edbc88fa41e9cb9c6b43d99b69278c9c5040
      https://github.com/llvm/llvm-project/commit/ab86edbc88fa41e9cb9c6b43d99b69278c9c5040
  Author: Stelios Ioannou <stelios.ioannou at arm.com>
  Date:   2021-03-15 (Mon, 15 Mar 2021)

  Changed paths:
    M clang/include/clang/Basic/BuiltinsAArch64.def
    M clang/lib/Basic/Targets/AArch64.cpp
    M clang/lib/Basic/Targets/AArch64.h
    M clang/lib/CodeGen/CGBuiltin.cpp
    M clang/lib/Headers/arm_acle.h
    M clang/test/CodeGen/arm_acle.c
    M clang/test/CodeGen/builtins-arm64.c
    M clang/test/Preprocessor/aarch64-target-features.c
    M llvm/include/llvm/IR/IntrinsicsAArch64.td
    M llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    M llvm/lib/Target/AArch64/AArch64ISelLowering.h
    M llvm/lib/Target/AArch64/AArch64InstrFormats.td
    M llvm/lib/Target/AArch64/AArch64InstrInfo.td
    A llvm/test/CodeGen/AArch64/rand.ll
    M llvm/test/CodeGen/AArch64/stp-opt-with-renaming.mir

  Log Message:
  -----------
  [AArch64] Implement __rndr, __rndrrs intrinsics

This patch implements the __rndr and __rndrrs intrinsics to provide access to the random
number instructions introduced in Armv8.5-A. They are only defined for the AArch64
execution state and are available when __ARM_FEATURE_RNG is defined.

These intrinsics store the random number in their pointer argument and return a status
code if the generation succeeded. The difference between __rndr __rndrrs, is that the latter
intrinsic reseeds the random number generator.

The instructions write the NZCV flags indicating the success of the operation that we can
then read with a CSET.

[1] https://developer.arm.com/docs/101028/latest/data-processing-intrinsics
[2] https://bugs.llvm.org/show_bug.cgi?id=47838

Differential Revision: https://reviews.llvm.org/D98264

Change-Id: I8f92e7bf5b450e5da3e59943b53482edf0df6efc