[PATCH] D25020: [ARM] Fix 26% performance regression on Cortex-A9 caused by not using VMLA/VMLS

[Evgeny Astigeevich via llvm-commits]

eastig added a comment.

I ran the LNT testsuite on Cortex-A9.

The results are:

**Performance Regressions - Execution Time**

| SingleSource/Benchmarks/Misc/himenobmtxpa  | 3.23% | VMLx. No obvious reason what caused this. |
| MultiSource/Benchmarks/McCat/09-vor/vor    | 3.08% | Don't see any VMLx related things         |
| SingleSource/Benchmarks/Misc-C++/Large/ray | 1.54% | VMLx                                      |
| SingleSource/Benchmarks/Misc/mandel        | 1.53% | Possibly VMLx                             |
| MultiSource/Benchmarks/Olden/em3d/em3d     | 1.31% | Don't see any VMLx related things         |

**Performance Improvements - Execution Time**

| SingleSource/Benchmarks/Misc/matmul_f64_4x4                               | -28.57% | VMLx |
| MultiSource/Benchmarks/ASC_Sequoia/IRSmk/IRSmk                            | -22.43% | VMLx |
| SingleSource/Benchmarks/Misc/ffbench                                      | -16.02% | VMLx |
| MultiSource/Benchmarks/TSVC/LoopRerolling-flt/LoopRerolling-flt           | -6.25%  | VMLx |
| MultiSource/Benchmarks/MiBench/consumer-lame/consumer-lame                | -6.15%  | VMLx |
| SingleSource/Benchmarks/Misc/oourafft                                     | -5.84%  | VMLx |
| SingleSource/Benchmarks/Misc/pi                                           | -5.39%  | VMLx |
| MultiSource/Benchmarks/TSVC/LoopRerolling-dbl/LoopRerolling-dbl           | -4.85%  | VMLx |
| SingleSource/Benchmarks/Misc-C++/mandel-text                              | -3.41%  | VMLx |
| MultiSource/Benchmarks/Bullet/bullet                                      | -2.68%  | VMLx |
| MultiSource/Benchmarks/FreeBench/pifft/pifft                              | -2.30%  | VMLx |
| MultiSource/Benchmarks/TSVC/CrossingThresholds-dbl/CrossingThresholds-dbl | -2.07%  | VMLx |
| SingleSource/Benchmarks/CoyoteBench/fftbench                              | -2.06%  | VMLx |
| MultiSource/Benchmarks/FreeBench/distray/distray                          | -1.94%  | VMLx |
| MultiSource/Benchmarks/SciMark2-C/scimark2                                | -1.90%  | VMLx |
| SingleSource/Benchmarks/Misc-C++/oopack_v1p8                              | -1.70%  | VMLx |
| MultiSource/Benchmarks/Olden/tsp/tsp                                      | -1.41%  | VMLx |
| MultiSource/Benchmarks/ASCI_Purple/SMG2000/smg2000                        | -1.34%  | VMLx |


https://reviews.llvm.org/D25020