Re: Creating tasks and the l4_task_map function

Hi all,

On Donnerstag, 29. September 2022 23:54:04 CEST Paul Boddie wrote:
> On Thursday, 29 September 2022 22:15:06 CEST Paul Boddie wrote:
> > So this kind of explains some of my earlier confusion about what should
> > happen on a 32-bit system. In fact, IA32 (x86) seems to be a special case,
> > although I cannot immediately find the documentation that explains why the
> > structure member alignment should be different from the rules applying to
> > other architectures.
> 
> Here is something that might be relevant:
> 
> "System V Application Binary Interface Intel386 Architecture Processor
> Supplement Version 1.0"
> 
> https://uclibc.org/docs/psABI-i386.pdf
> 
> Specifically, table 2.1 on page 8 shows that the long long types are 64-bit
> types with 32-bit alignment.

True, and gcc confirms that:

  $ cat foo.cc
  #include <cstdio>
  int main() { printf("%zd\n", alignof(long long)); return 0; }

  $ uname -m
  x86_64

  $ g++ -Wall -Wextra -o foo foo.cc && ./foo
  8

  $ g++ -m32 -Wall -Wextra -o foo foo.cc && ./foo
  4

Kind regards,

Frank
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