NiccoloN
21 lines
1.0 KiB
Markdown
21 lines
1.0 KiB
Markdown
# Parallelism and Runtime Invariant
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Compile-time optimization must not trade away execution parallelism or worsen
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theoretical runtime behavior. The absence of a precise runtime measurement does
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not make such a trade acceptable.
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In particular, a compile-time optimization must not:
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- serialize work that can execute independently;
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- coarsen lane, core, batch, or scheduling granularity in a way that reduces
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available execution parallelism;
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- increase the theoretical runtime critical path, instruction count, memory
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traffic, synchronization, or required copies merely to reduce compiler work;
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- merge independently scheduled work when doing so may reduce concurrency.
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Compiler representations may share analysis, planning, or code-generation
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work only when the emitted execution retains the same independent work,
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schedule semantics, and available parallelism. If runtime impact cannot be
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measured precisely, it must be established from the transformation's semantics;
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uncertainty is not permission to accept a possible runtime regression.
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