2014-04-03 17:51 GMT+02:00 karl ramberg <karlramberg@gmail.com>:
I can confirm this bug on windows Cog.
Cheers, Karl
On Thu, Apr 3, 2014 at 10:11 AM, Nicolai Hess <nicolaihess@web.de> wrote:
There is still something wrong with byte/word swap in windows ioShowDisplay code attached are two screenshots squeak 4.5 image with cogvm from http://files.pharo.org/vm/cogmt/win/ pharo 30793 image with latest vm from http://files.pharo.org/vm/pharo/win/ showing this bug after setting the Display depth to 16 (Display newDepth:16)
sqwin32window.c has three variants for doing the byte_swap/word_swap on bitdepths with big endian to convert to lsb
This one is active and causes this error. # if __GNUC__ >= 3 # define BYTE_SWAP(w) __asm__("bswap %0" : "=r" (w) : "r" (w)) # define WORD_SWAP(w) __asm__("roll $16, %0" : "=r" (w) : "r" (w))
This one would work # else # define BYTE_SWAP(w) __asm__("bswap %%eax" : "=eax" (w) : "eax" (w)) # define WORD_SWAP(w) __asm__("roll $16, %%eax" : "=eax" (w) : "eax" (w))
This one, of course, works too # else # define BYTE_SWAP(w) w = (w << 24) | ((w & 0xFF00) << 8) | ((w >> 8) & 0xFF00) | (w >> 24) # define WORD_SWAP(w) w = (( (unsigned)(w) << 16) | ((unsigned) (w) >> 16))
This one is not there but would work (at least with gcc > 4.5 # define BYTE_SWAP_MY(w) __asm__("bswap %0" : "+r" (w)) # define WORD_SWAP_MY(w) __asm__("roll $16, %0" : "+r" (w))
But actually I don't know assembler and/or the gcc inline code syntax, so I don't know what is wrong with the first version :)
Nicolai
btw, you can not test this bug with the current squeak 4.5 all in on image, as it uses a rather old vm.
Third screenshot: using the latest stable pharo-vm, it looks much more wrong, as there was another(?) bug that is fixed already(?) - i don't know :)
Someone else can reproduce this? (eliot?, nicolas? ) It is easily fixable, I think. But I am not good at inline assembler. I'll open a mantis and fogbugz report. regards Nicolai