[all-commits] [llvm/llvm-project] 4756a2: [X86] Insert FMUL for estimated non reciprocal SQR...

[Phoebe Wang via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4756a2f1575cd78197f00ffdaa1491f9ec78c576
      https://github.com/llvm/llvm-project/commit/4756a2f1575cd78197f00ffdaa1491f9ec78c576
  Author: Phoebe Wang <phoebe.wang at intel.com>
  Date:   2021-12-02 (Thu, 02 Dec 2021)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/sqrt-fastmath.ll

  Log Message:
  -----------
  [X86] Insert FMUL for estimated non reciprocal SQRT when `RefinementSteps` = 0

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D114843


  Commit: f13b43d5702bed381bb1717e2336f7f23ae722b4
      https://github.com/llvm/llvm-project/commit/f13b43d5702bed381bb1717e2336f7f23ae722b4
  Author: Phoebe Wang <phoebe.wang at intel.com>
  Date:   2021-12-02 (Thu, 02 Dec 2021)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/avx512fp16-intrinsics.ll
    M llvm/test/CodeGen/X86/avx512fp16vl-intrinsics.ll

  Log Message:
  -----------
  [X86][FP16] Only generate approximate rsqrt when Reciprocal is true for half type

We have reasonable fast sqrt and accurate rsqrt for half type due to the
limited fractions. So neither do we need multi steps refinement for
rsqrt nor replace sqrt by rsqrt.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D114844


Compare: https://github.com/llvm/llvm-project/compare/fcd2d85cc943...f13b43d5702b