Optimize fsst_compress_offsets_overflow_i32 by 2X locally

[AdamGS]

Summary

Optimize the infamous fsst_compress_offsets_overflow_i32 test by dropping the symbol table - instead compressing with an empty symbol table to get constant escapes.

Locally this change drops the test's runtime from 136s to 57s (in normal test profile), which should have a real impact on our CI runtimes.

This change is provided by the new fable-5 model.

[codspeed-hq]

Merging this PR will improve performance by 21.56%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚡ 3 improved benchmarks
✅ 1523 untouched benchmarks

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	bitwise_not_vortex_buffer_mut[128]	275.3 ns	216.9 ns	+26.89%
⚡	Simulation	bitwise_not_vortex_buffer_mut[1024]	336.9 ns	278.6 ns	+20.94%
⚡	Simulation	bitwise_not_vortex_buffer_mut[2048]	400.6 ns	342.2 ns	+17.05%

Tip

Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing adamg/optimize-test-fsst-overflow (c00b58c) with develop (4b6c382)}

[joseph-isaacs]

We could run this in release with debug assert too?

[0ax1]

Thaaaank you

[AdamGS]

@joseph-isaacs we can, last time I looked running tests in release was much slower and specializing one test is brittle, I think this already makes it much better.