[RFC PATCH 2/7] lmb: Simplify lmb_addrs_overlap()

[Ilias Apalodimas]

Hi Heinrich

On Sun, 8 Dec 2024 at 13:31, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> Am 8. Dezember 2024 11:52:05 MEZ schrieb Ilias Apalodimas <ilias.apalodimas at linaro.org>:
> >There's no point subtracting -1 from the calculated addresses and then
> >check for a <= b. Just remove the -1 and check for a < b.
>
> I once thought that, too. But it makes a difference for end= U(L)LONG_MAX.

If those addresses overflow then we have to add more checks -- e.g
if (base2_end < base2)
{
     Do something wrong
}

In which case, I prefer modifying the function and add those checks

Thoughts?
/Ilias

>
> Best regards
>
> Heinrich
>
> >
> >Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> >---
> > lib/lmb.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> >diff --git a/lib/lmb.c b/lib/lmb.c
> >index a7ecbb58831f..c7bf5120696f 100644
> >--- a/lib/lmb.c
> >+++ b/lib/lmb.c
> >@@ -36,10 +36,10 @@ DECLARE_GLOBAL_DATA_PTR;
> > static long lmb_addrs_overlap(phys_addr_t base1, phys_size_t size1,
> >                             phys_addr_t base2, phys_size_t size2)
> > {
> >-      const phys_addr_t base1_end = base1 + size1 - 1;
> >-      const phys_addr_t base2_end = base2 + size2 - 1;
> >+      const phys_addr_t base1_end = base1 + size1;
> >+      const phys_addr_t base2_end = base2 + size2;
> >
> >-      return ((base1 <= base2_end) && (base2 <= base1_end));
> >+      return ((base1 < base2_end) && (base2 < base1_end));
> > }
> >
> > static long lmb_addrs_adjacent(phys_addr_t base1, phys_size_t size1,
>