[all-commits] [llvm/llvm-project] 19cdd1: [AArch64][GlobalISel] Add heuristics for localizin...

[Amara Emerson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 19cdd1908b173a0a4bdf29a18c689729fc3497ac
      https://github.com/llvm/llvm-project/commit/19cdd1908b173a0a4bdf29a18c689729fc3497ac
  Author: Amara Emerson <amara at apple.com>
  Date:   2022-07-27 (Wed, 27 Jul 2022)

  Changed paths:
    M llvm/include/llvm/CodeGen/MachineRegisterInfo.h
    M llvm/lib/CodeGen/MachineRegisterInfo.cpp
    M llvm/lib/CodeGen/TargetLoweringBase.cpp
    M llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    M llvm/test/CodeGen/AArch64/GlobalISel/localizer-arm64-tti.ll

  Log Message:
  -----------
  [AArch64][GlobalISel] Add heuristics for localizing G_CONSTANT.

This adds similar heuristics to G_GLOBAL_VALUE, querying the cost of
materializing a specific constant in code size. Doing so prevents us from
sinking constants which require multiple instructions to generate into
use blocks.

Code size savings on CTMark -Os:
Program                                       size.__text
                                              before         after           diff
ClamAV/clamscan                               381940.00      382052.00       0.0%
lencod/lencod                                 428408.00      428428.00       0.0%
SPASS/SPASS                                   411868.00      411876.00       0.0%
kimwitu++/kc                                  449944.00      449944.00       0.0%
Bullet/bullet                                 463588.00      463556.00      -0.0%
sqlite3/sqlite3                               284696.00      284668.00      -0.0%
consumer-typeset/consumer-typeset             414492.00      414424.00      -0.0%
7zip/7zip-benchmark                           595244.00      594972.00      -0.0%
mafft/pairlocalalign                          247512.00      247368.00      -0.1%
tramp3d-v4/tramp3d-v4                         372884.00      372044.00      -0.2%
                           Geomean difference                               -0.0%

Differential Revision: https://reviews.llvm.org/D130554