Eliminate hard-coded BN_N_LIMBS and BN_LIMB_WIDTH dependency.
#327
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adr1anh
reviewed
Feb 16, 2024
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| let carry_bits = (((max_word.to_f64().unwrap() * 2.0).log2() - self.params.limb_width as f64) | ||
| .ceil() | ||
| + 0.1) as usize; |
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This seems like it could lead to unexpected results in some situations due to a potential loss of precision with floats.
adr1anh
reviewed
Feb 16, 2024
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The change looks good to me, though I haven't looked into this gadget enough to understand if this is enough to support arbitrary configurations. Ideally, we should replace this with bellpepper-gadgets/emulated. |
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The change does seem reasonable to me, and can be backported to Nova too, even if we move to |
adr1anh
approved these changes
Feb 26, 2024
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In an attempt to see what would happen to the number of constraints if we changed the parameters
BN_N_LIMBSandBN_LIMB_WIDTH, I found a couple places where the arithmetic inadvertently was dependent on the values being hardcoded as 4 and 64 respectively.I believe this PR makes the necessary changes to make the codebase general enough to allow for varying these parameters. The expect tests expectedly (:drum: haha) fail when changing these two constants, but everything else passes.