[all-commits] [llvm/llvm-project] 257251: [SROA] Try harder to find a vector promotion viabl...

[vangthao95 via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 257251247a267c3fa30fdeef17ffa4987d8a52e5
      https://github.com/llvm/llvm-project/commit/257251247a267c3fa30fdeef17ffa4987d8a52e5
  Author: Vang Thao <Vang.Thao at amd.com>
  Date:   2022-08-08 (Mon, 08 Aug 2022)

  Changed paths:
    M llvm/lib/Transforms/Scalar/SROA.cpp
    A llvm/test/Transforms/SROA/sroa-common-type-fail-promotion.ll

  Log Message:
  -----------
  [SROA] Try harder to find a vector promotion viable type when rewriting

We are seeing significant performance loss when an alloca fails to get promoted
to register. I have observed that this is due to the common type found when
attempting to rewrite partition users being unviable for promotion. While if we
would have continue looking for a type, we would have found a subtype in the
original allocated type that would have enabled promotion. Thus first check if
the initial common type found is promotion viable and if not then continue
looking instead of stopping with the initial common type found.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D128073