[all-commits] [llvm/llvm-project] 2556f5: [FuncSpec] Don't specialize function which are eas...

[Chuanqi Xu via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2556f58148836f0af3ad2c73fe54bbdf49f0295a
      https://github.com/llvm/llvm-project/commit/2556f58148836f0af3ad2c73fe54bbdf49f0295a
  Author: Chuanqi Xu <yedeng.yd at linux.alibaba.com>
  Date:   2021-08-23 (Mon, 23 Aug 2021)

  Changed paths:
    M llvm/lib/Transforms/IPO/FunctionSpecialization.cpp
    A llvm/test/Transforms/FunctionSpecialization/function-specialization-always-inline.ll
    M llvm/test/Transforms/FunctionSpecialization/function-specialization-constant-integers.ll
    M llvm/test/Transforms/FunctionSpecialization/function-specialization-loop.ll
    M llvm/test/Transforms/FunctionSpecialization/function-specialization-stats.ll
    M llvm/test/Transforms/FunctionSpecialization/function-specialization2.ll

  Log Message:
  -----------
  [FuncSpec] Don't specialize function which are easy to inline

It would waste time to specialize a function which would inline finally.
This patch did two things:

- Don't specialize functions which are always-inline.
- Don't spescialize functions whose lines of code are less than threshold
(100 by default).

For spec2017int, this patch could reduce the number of specialized
functions by 33%. Then the compile time didn't increase for every
benchmark.

Reviewed By: SjoerdMeijer, xbolva00, snehasish

Differential Revision: https://reviews.llvm.org/D107897