Re: [PATCH xserver] squash! sync: Convert from "CARD64" to int64_t.

Michel Dänzer writes: > Is assigning an unsigned value with the MSB set to a signed variable > well-defined in C? I have no idea. And I just spent a few hours wading through the N1570 draft of the C standard on a related issue. In particular, this is worrying: 6.3.1.3 3

Re: [PATCH xserver] squash! sync: Convert from "CARD64" to int64_t.

On 25/08/17 03:57 AM, Eric Anholt wrote: > --- > > We pass the overflow unit tests both before and after this change, but > this should be safer. > > include/misc.h | 8 ++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/include/misc.h b/include/misc.h > index

Re: [PATCH xserver] squash! sync: Convert from "CARD64" to int64_t.

Eric Anholt writes: > --- > > We pass the overflow unit tests both before and after this change, but > this should be safer. I've seen GCC do precisely the 'optimization' you are concerned about, but only when one of the operands is constant. One should use -fwrapv whenever

[PATCH xserver] squash! sync: Convert from "CARD64" to int64_t.

--- We pass the overflow unit tests both before and after this change, but this should be safer. include/misc.h | 8 ++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/include/misc.h b/include/misc.h index 0feeaebc7c1a..9d0e422e36b4 100644 --- a/include/misc.h +++

Re: [PATCH xserver 6/7 v2] sync: Convert from "CARD64" to int64_t.

2017-08-23 22:06 GMT+05:00 Eric Anholt : > diff --git a/include/misc.h b/include/misc.h > index 38af70ff9e89..0feeaebc7c1a 100644 > --- a/include/misc.h > +++ b/include/misc.h > @@ -324,6 +324,31 @@ bswap_32(uint32_t x) > ((x & 0x00FF) << 24)); > } > > +static