Re: [PATCH] libstdc++: optimize bit iterators assuming normalization [PR110807]

2023-11-08 Thread Jonathan Wakely
On 08/11/23 13:10 -0300, Alexandre Oliva wrote: The representation of bit iterators, using a pointer into an array of words, and an unsigned bit offset into that word, makes for some optimization challenges: because the compiler doesn't know that the offset is always in a certain narrow range, be

[PATCH] libstdc++: optimize bit iterators assuming normalization [PR110807]

2023-11-08 Thread Alexandre Oliva
The representation of bit iterators, using a pointer into an array of words, and an unsigned bit offset into that word, makes for some optimization challenges: because the compiler doesn't know that the offset is always in a certain narrow range, beginning at zero and ending before the word bitwi