Add runtime overflow checker #463
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The interface is `would_value_overflow<Op>(x)`, where `x` is a value of type `OpInput<Op>`. This interface is already good enough to replace both the implicit-rep and explicit-rep versions of the runtime overflow checkers! Except that we can't just yet, because we're not _actually using an operation_ to implement our conversions. Along the way, we add (and test) some other helpful utilities, some of which are useful in other places. For example, we'll make use of `CanOverflowAbove` in our implicit conversion policy. `MinValueChecker` and `MaxValueChecker` are designed to produce functions that unconditionally return `false` for their `is_too_XX()` members. This should make it very easy for the compiler to produce very efficient assembly for `would_value_overflow()`. Helps #349: at this point, the `:overflow_boundary` target should be complete and ready for production!
hoffbrinkle
approved these changes
Jul 18, 2025
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The interface is
would_value_overflow<Op>(x), wherexis a value oftype
OpInput<Op>. This interface is already good enough to replaceboth the implicit-rep and explicit-rep versions of the runtime overflow
checkers! Except that we can't just yet, because we're not actually
using an operation to implement our conversions.
Along the way, we add (and test) some other helpful utilities, some of
which are useful in other places. For example, we'll make use of
CanOverflowAbovein our implicit conversion policy.MinValueCheckerandMaxValueCheckerare designed to producefunctions that unconditionally return
falsefor theiris_too_XX()members. This should make it very easy for the compiler to produce very
efficient assembly for
would_value_overflow().Helps #349: at this point, the
:overflow_boundarytarget should becomplete and ready for production!