Re: in ccio_io_pdir_entry(),BUG_ON() seems to break gcc-4.2 optimization?

["Joel Soete" <soete.joel@scarlet.be>]

Just for remind:

Joel Soete wrote:
 >
 >
[snip]
 >>> But this time, it seems not consider assembly:
 >>>         asm volatile ("lci %%r0(%%sr1, %1), %0" : "=r" (ci) : "r"
 >>> (vba));
 >>>         asm volatile ("extru %1,19,12,%0" : "+r" (ci) : "r" (ci));
 >>>         asm volatile ("depw  %1,15,12,%0" : "+r" (pa) : "r" (ci));
 >>>
 >>> as a 'volatile' block and insert line 1c:

This seems to make better what I want:
        __asm__ __volatile__ (
        "lci    %%r0(%%sr1, %2), %0\n"
        "\textru        %0,19,12,%0\n"
        "\tdepw         %0,15,12,%1\n"
        : "+r" (ci), "+r" (pa)
        : "r" (vba)
        : "memory"
        );


in <ccio_map_sg>
  200:	06 80 53 13 	lci r0(sr1,r20),r19		      |	 200:	08 1a 02 54 	copy r26,r20
  204:	d2 73 1a 74 	extrw,u r19,19,12,r19		      |	 204:	06 a0 53 14 	lci
r0(sr1,r21),r20
  208:	08 1a 02 5c 	copy r26,ret0			      |	 208:	d2 94 1a 74 	extrw,u
r20,19,12,r20
  20c:	d7 93 0e 14 	depw r19,15,12,ret0		      |	 20c:	d7 94 0e 14 	depw
r20,15,12,ret0
  210:	0e dc 12 80 	stw ret0,0(r22)				 210:	0e dc 12 80 	stw ret0,0(r22)
  214:	06 c0 12 80 	fdc r0(r22)				 214:	06 c0 12 80 	fdc r0(r22)
  218:	00 00 04 00 	sync					 218:	00 00 04 00 	sync

J.

PS: I don't yet understand why kernel panicing when I try to get rid to
reserve 'ci' variable and use in place a gr as r19 (even if clobbered), the
produced object seems ok but resulting kernel panicing (even after a full
rebuild after a make distclean???)