This repository contains several low-level optimizations of the Gaussian Elimination algorithm.
Made as a part of Code Optimizations on Different Architectures course at the AGH University of Science and Technology.
Optimizations are located in the src directory and named ge#.c, where # - optimization number.
Basic Gaussian Elimination implementation.
Counters are moved to registers.
Multiplier, i.e.
multiplier = A[i][k] / A[k][k]is moved to register and extracted from the most inner loop.
The third loop is unrolled by 8.
Matrix representation was changed to 1D array.
SSE instructions are used.
AVX-256 instructions are used.
AVX-512 instructions are used.
The project requires PAPI to be installed (tested with PAPI 7.0.1.0). PAPI provides a programmer interface to monitor the performance of running programs.
On Fedora, PAPI can be installed by executing the following command:
sudo dnf install papi-develImportant
In order to run the prepared benchmarks, your CPU must at least support the following counters:
| Counter | Description |
|---|---|
PAPI_FP_OPS |
Floating point operations |
PAPI_TOT_INS |
Instructions completed |
PAPI_TOT_CYC |
Total cycles |
PAPI_BR_TKN |
Conditional branch instructions taken |
PAPI_BR_MSP |
Conditional branch instructions mispredicted |
Supported counters can be checked by executing
papi_avail | grep YesMoreover, in order to run ge6, ge7 and ge8 optimizations,
your CPU must support SSE, AVX-256 and AVX-512 accordingly.
It can be checked by executing lscpu command.
- Materiały do laboratorium 2 – dr hab. inż. Maciej Woźniak
- Materiały do laboratorium 3 – dr hab. inż. Maciej Woźniak
- Materiały do laboratorium 4 – dr hab. inż. Maciej Woźniak
- How To Optimize Gemm – flame: https://github.com/flame/how-to-optimize-gemm