Disable jump threading of float equality #826
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Veykril
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Jump threading stores values as `u128` (`ScalarInt`) and does its comparisons for equality as integer comparisons. This works great for integers. Sadly, not everything is an integer. Floats famously have wonky equality semantcs, with `NaN!=NaN` and `0.0 == -0.0`. This does not match our beautiful integer bitpattern equality and therefore causes things to go horribly wrong. While jump threading could be extended to support floats by remembering that they're floats in the value state and handling them properly, it's signficantly easier to just disable it for now. Ferrocene-backport-of: #128271
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Jump threading stores values as
u128(ScalarInt) and does its comparisons for equality as integer comparisons.This works great for integers. Sadly, not everything is an integer.
Floats famously have wonky equality semantcs, with
NaN!=NaNand0.0 == -0.0. This does not match our beautiful integer bitpattern equality and therefore causes things to go horribly wrong.While jump threading could be extended to support floats by remembering that they're floats in the value state and handling them properly, it's signficantly easier to just disable it for now.
Ferrocene-backport-of: rust-lang/rust#128271