On Mon, Sep 13, 2021 at 10:58 AM Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:
On Mon, Sep 13, 2021 at 09:52:33PM +0530, Naresh Kamboju wrote:
[PATCH 00/10] raise minimum GCC version to 5.1 https://lore.kernel.org/lkml/20210910234047.1019925-1-ndesaulniers@google.co...
Has anyone submitted a fix for this upstream yet? I can't seem to find one :(
That lore link has a series to address this, though that's maybe something we don't want to backport to stable.
I thought about this all weekend; I think I might be able to work around the one concern I had with my other approach, using __builtin_choose_expr().
There's an issue with my alternative approach (https://gist.github.com/nickdesaulniers/2479818f4983bbf2d688cebbab435863) with declaring the local variable z in div_64() since either operand could be 64b, which result in an unwanted truncation if the dividend is 32b (or less, and divisor is 64b). I think (what I realized this weekend) is that we might be able to replace the `if` with `__builtin_choose_expr`, then have that whole expression be the final statement and thus the "return value" of the statement expression.
I need to play with that idea more; maybe that could be a more manageable patch for stable. But I also need to eat lunch, and I've been in the Rust for Linux conference, and trying to organize 3 other conferences for the next two weeks...