[all-commits] [llvm/llvm-project] 39af46: [AArch64][SVE] Replace destructive operand of vect...

[Allen via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 39af4659f24026fd3c667ce50a9e798485e1ae98
      https://github.com/llvm/llvm-project/commit/39af4659f24026fd3c667ce50a9e798485e1ae98
  Author: zhongyunde <zhongyunde at huawei.com>
  Date:   2023-02-07 (Tue, 07 Feb 2023)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp
    M llvm/lib/Target/AArch64/AArch64SVEInstrInfo.td
    M llvm/lib/Target/AArch64/SVEInstrFormats.td
    A llvm/test/CodeGen/AArch64/sve2-intrinsics-fp-int-binary-logarithm-zeroing.ll

  Log Message:
  -----------
  [AArch64][SVE] Replace destructive operand of vector zeros with a bundled MOVPRFX instruction

Replace unary instructions where the destructive operand is a vector of zeros
with a bundled MOVPRFX instruction, e.g:
       Transform:
           %X0 = DUP_ZI_S 0, 0
           %X0 = FLOGB_ZPmZ_S X0, P0, X2
        into:
            X0 = MOVPRFX P0/z, X1  // doesn't introduce any fake register dependencies compare to X0 = MOVPRFX P0/z, X0
            X0 = FLOGB_ZPmZ_S X0, P0, X2
NOTE: This patch add a @earlyclobber constraint to PredOneOpPassthruPseudo to ensure
    safe register allocation for movprfx usage.

Depends on D105889

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D138888