Re: [PATCH 3/3] qemu-timer: reuse MIN macro in qemu_timeout_ns_to_ms

[Eric Blake]

On 10/23/19 9:45 AM, Laurent Vivier wrote:

> > The C rules for ternary type promotion guarantee that the MIN macro
> > produces the correct type without the cast ('cond ? int64_t : int32_t'
> > produces int64_t).
>
> gdb seems to disagree with that:
>
> (gdb) whatis l
> type = long long
> (gdb) whatis i
> type = int
> (gdb) whatis 1 ? l : i
> type = long long
> (gdb) whatis 0 ? l : i
> type = int

It looks like you've found a gdb bug.

C99 6.5.15 p5 states:
"If both the second and third operands have arithmetic type, the result 
type that would be determined by the usual arithmetic conversions, were 
they applied to those two operands, is the type of the result."

and the usual arithmetic conversion of 'long long OP int' is 'long 
long', per 6.3.1.8.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org