[PATCH] D61947: Merge of Global Constants not happening on Aarch64

[Ramakota Reddy via Phabricator via llvm-commits]

ramred01 added a comment.

In D61947#1503450 <https://reviews.llvm.org/D61947#1503450>, @efriedma wrote:

> This probably makes sense (the change basically just makes this code match 32-bit ARM), but I'd like to see codesize and performance numbers, since this will substantially change code generation in a lot of cases.


Here are the performance numbers for the LNT and SPEC Benchmarks:

`Performance Regressions - execution_time
=========================================

External/SPEC/CINT2000/164.gzip/164.gzip                   2.13%

Performance Improvements - execution_time
=========================================

MultiSource/Benchmarks/VersaBench/8b10b/8b10b         	  -8.50%
SingleSource/Benchmarks/McGill/queens                     -5.98%
SingleSource/Benchmarks/Misc/himenobmtxpa                 -3.99%
MultiSource/Applications/aha/aha                          -3.17%
SingleSource/Benchmarks/Adobe-C++/loop_unroll             -2.23% 
MultiSource/Benchmarks/TSVC/Expansion-dbl/Expansion-dbl   -2.10%
External/SPEC/CINT2000/186.crafty/186.crafty              -1.46% 
MultiSource/Benchmarks/TSVC/StatementReordering-dbl/StatementReordering-dbl   -1.21% 
SingleSource/Benchmarks/Misc/richards_benchmark           -1.10%

Performance Improvements - mem_bytes
====================================

SingleSource/Benchmarks/Misc/flops-5                     -12.00% 
SingleSource/Benchmarks/Misc/flops-8                     -11.93%
SingleSource/Benchmarks/Misc/flops                       -11.64%`

As can be seen, except for a performance degradation of 2.13% in gzip, there is 1-8.5% performance improvements in execution time and about 12% in code size for some of the benchmarks, the last one being more relevant since we are optimizing for code size.

These numbers were obtained by running the benchmarks with -Oz (and not -O3), both for the baseline run as well as with the patch.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D61947/new/

https://reviews.llvm.org/D61947