Segher Boessenkool <seg...@kernel.crashing.org> writes:
> PowerPC's "cmp" instruction has four operands. Normally people write
> "cmpw" or "cmpd" for the second cmp operand 0 or 1. But, frequently
> people forget, and write "cmp" with just three operands.
>
> With older binutils this is silently accepted as if this was "cmpw",
> while often "cmpd" is wanted. With newer binutils GAS will complain
> about this for 64-bit code. For 32-bit code it still silently assumes
> "cmpw" is what is meant.
Thanks.
Anton already sent a fix for the two vdso ones, which were real bugs,
and that's now in Linus' tree.
> diff --git a/arch/powerpc/include/asm/cpuidle.h
> b/arch/powerpc/include/asm/cpuidle.h
> index 01b8a13..3919332 100644
> --- a/arch/powerpc/include/asm/cpuidle.h
> +++ b/arch/powerpc/include/asm/cpuidle.h
> @@ -26,7 +26,7 @@ extern u64 pnv_first_deep_stop_state;
#define IDLE_STATE_ENTER_SEQ(IDLE_INST) \
/* Magic NAP/SLEEP/WINKLE mode enter sequence */ \
> std r0,0(r1); \
> ptesync; \
> ld r0,0(r1); \
> -1: cmp cr0,r0,r0; \
> +1: cmpd cr0,r0,r0; \
> bne 1b; \
> IDLE_INST; \
> b .
What's this one doing, is it a bug? I can't really tell without knowing
what the magic sequence is meant to do.
Mahesh, Vaidy?
cheers
