[all-commits] [llvm/llvm-project] a3d0dc: [ARM][TTI] Prevents constants in a min(max) or max...

[Meera Nakrani via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: a3d0dce2608bb399f2bf0122d8c6a4c7b4d6c1fa
      https://github.com/llvm/llvm-project/commit/a3d0dce2608bb399f2bf0122d8c6a4c7b4d6c1fa
  Author: Meera Nakrani <meera.nakrani at arm.com>
  Date:   2020-09-22 (Tue, 22 Sep 2020)

  Changed paths:
    M llvm/include/llvm/Analysis/TargetTransformInfo.h
    M llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
    M llvm/lib/Analysis/TargetTransformInfo.cpp
    M llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
    M llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
    M llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
    M llvm/lib/Target/ARM/ARMTargetTransformInfo.h
    M llvm/lib/Target/Lanai/LanaiTargetTransformInfo.h
    M llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
    M llvm/lib/Target/PowerPC/PPCTargetTransformInfo.h
    M llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
    M llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h
    M llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp
    M llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h
    M llvm/lib/Target/X86/X86TargetTransformInfo.cpp
    M llvm/lib/Target/X86/X86TargetTransformInfo.h
    M llvm/lib/Transforms/Scalar/ConstantHoisting.cpp
    M llvm/test/CodeGen/Thumb2/mve-satmul-loops.ll

  Log Message:
  -----------
  [ARM][TTI] Prevents constants in a min(max) or max(min) pattern from being hoisted when in a loop

Changes TTI function getIntImmCostInst to take an additional Instruction parameter,
which enables us to be able to check it is part of a min(max())/max(min()) pattern that will match SSAT.
We can then mark the constant used as free to prevent it being hoisted so SSAT can still be generated.
Required minor changes in some non-ARM backends to allow for the optional parameter to be included.

Differential Revision: https://reviews.llvm.org/D87457