[GlobalOptimization]fixed constexpr to avoid hoisting dequant operations #22416
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Signed-off-by: VimalWill <[email protected]>
VimalWill
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Groverkss
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Oct 26, 2025
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| // Check 4: Does hoisting this value significantly increase the size of the | ||
| // module? | ||
| if (doesHoistingIncreaseSizeSignificantly( | ||
| info, constExprMaxSizeIncreaseThreshold)) { | ||
| return decision->disableHoist(); |
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Wouldn't this already be handled by this?
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In some cases, the size-based heuristic may fail to detect dequantization hoisting (e.g., for tensors like tensor<3x3x3x32xi8>), resulting in inflated global constants. Introducing the semantic-based condition ensures such bit-extend (i8→f32) operations are excluded from hoisting, preventing unnecessary runtime memory overhead and preserving quantized model compactness.
PS: I found it's hosting dequantization (3x3x3x32xI8 -> 3x3x3x32xf32)
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@Groverkss, what's your idea on this ?
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The PR includes a fix to prevent hoisting of the bit extension (i.e., the dequantization operation), which was previously missing in ConstExpr.cpp. The absence of this logic caused the dequantization operation to be incorrectly hoisted in HoistIntoGlobalsPass.cpp.
Regards,
Vimal William