The example you provided doesn't match what I'm finding with my 64-bit Microsoft Platform SDK for Windows Server 2003 R2 compiler on Vista 64. This compiler has 32-bit longs and ints - yet those high order bits are, I think, being lost to the "big bit bucket in the sky": 
use warnings;
use Inline C => Config =>
    BUILD_NOISY => 1;

use Inline C => <<'EOC';

void foo() {
     unsigned long x = 0xffffffff;
     printf("long: %d\nint: %d\n", sizeof(long), sizeof(int));
     printf("%x\n", x);
     x  <<= 2;
     printf("%x\n", x);
     x >>= 2;
     printf("%x\n", x);
}


EOC

foo();

__END__
Outputs:
long: 4
int: 4
ffffffff
fffffffc
3fffffff

[download]
Maybe this behaviour is not reliable across the full range of compilers/systems/architectures. (I honestly wouldn't know.)

Unfortunately you can't use sizeof in a preprocessor directive to do the setup one way on a 32 bit machine and another way on a 64 bit one

Yes - I was finding that out for myself (probably as you were writing your reply :-)

However, you can have the Makefile.PL query $Config{intsize} and $Config{longsize}. And the Makefile.PL can then define symbols (based on those config values) that the pre-processor can make use of.

Cheers,
Rob

In reply to Re^3: Perl XS portable uint32_t by syphilis
in thread Perl XS portable uint32_t by tachyon-II

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