GCC/Clang Optimizations for Embedded Linux

on YouTube ↗54m

" summary

Describes practical compiler levers for embedded Linux with exact flags and tradeoffs including -Os vs -O3 for size versus speed and the reason -O3 inflates code (loop unrolling) and auto vectorization needs SIMD targets. Shows how to use fstack-usage, -fconserve-stack, function/data sectioning plus linker GC to shrink images, and how LTO and PGO work including instrumented PGO versus sampling Auto SDO. Advises profiling hotspots, using -march/-mtune/-mcpu carefully, and avoiding nonportable GCC extensions that clang rejects.

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" chapters (17)

1. 0:00Introduction
2. 1:06Clang
3. 2:32GCC
4. 4:40Optimization Flags
5. 10:13Optimization Flags Output
6. 12:24Strictaliasing
7. 15:27Inlining
8. 19:04Stack Optimization
9. 22:19Size Optimization
10. 26:38Profile Guided Optimization
11. 27:50Profile Generate
12. 32:14LTO
13. 37:20AutoVectorization
14. 42:23CPU Optimizations
15. 46:32Builtin Functions
16. 47:53Unsupported Extensions
17. 51:13Summary

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