ide_delay_50ms() freezing on PPC?

Michel Lanners mlan at
Thu Jun 29 16:02:17 EST 2000

Hi all,

On  27 Jun, this message from Benjamin Herrenschmidt echoed through cyberspace:
> Can you check the generated code for the loop ? Does it actually re-dead
> jiffies from memory or not ? (Did the compiler wrongly tried to optimise
> it ?).

Here is the code as it appears in vmlinux:

c00ba91c <ide_delay_50ms>:
c00ba91c:       3d 20 c0 21     lis     r9,-16351
c00ba920:       81 69 c1 ec     lwz     r11,-15892(r9)
c00ba924:       39 6b 00 06     addi    r11,r11,6
c00ba928:       80 09 c1 ec     lwz     r0,-15892(r9)
c00ba92c:       7d 40 58 51     subf.   r10,r0,r11
c00ba930:       41 81 ff f8     bgt     c00ba928 <ide_delay_50ms+0xc>
c00ba934:       4e 80 00 20     blr

I suppose r9 points to a symbol table somewhere, and the lwz loads a
specific symbol in there, which in this case should be the value of
jiffies. AFAICS, the jiffies value is thus correctly reloaded at
c00ba928. Looks OK to me, no?


Michel Lanners                 |  " Read Philosophy.  Study Art.
23, Rue Paul Henkes            |    Ask Questions.  Make Mistakes.
L-1710 Luxembourg              |
email   mlan at            |        |                     Learn Always. "

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