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sav08:bitwidth_analysis [2008/05/20 18:56] vkuncak |
sav08:bitwidth_analysis [2008/05/20 23:59] vkuncak |
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| Given a language with signed 64 bit integers, determine as small as possible set of bits needed to store values of variables. | Given a language with signed 64 bit integers, determine as small as possible set of bits needed to store values of variables. | ||
| * e.g. if analysis derives that a subset of $\{0,1,2,\ldots,7\}$ is sufficient, then we can use //byte// type to store the value | * e.g. if analysis derives that a subset of $\{0,1,2,\ldots,7\}$ is sufficient, then we can use //byte// type to store the value | ||
| - | * the analysis becomes even more important if we generate hardware from C code (saving wires) | + | * instead of having multiple integer types, we can have analysis infer the right 'subtypes' (ranges) |
| + | * the analysis becomes even more important if we generate hardware from C code: analysis would enable us to save circuits and power | ||
| Let B = {-32,-31,...,-1,0,1,...,31} be a set of bits. | Let B = {-32,-31,...,-1,0,1,...,31} be a set of bits. | ||
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| \] | \] | ||
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| + | Is this the most precise rule possible? ++|No, consider adding only even numbers.++ | ||
| ===== References ===== | ===== References ===== | ||