Re: [PATCH] powerpc: fix xmon disassembler for little-endian

On Wed, 2013-12-04 at 14:45 +0100, Philippe Bergheaud wrote:

quoted

quoted

+#ifdef __LITTLE_ENDIAN__
+#define GETWORD(v)	(((v)[3] << 24) + ((v)[2] << 16) + ((v)[1] << 8) + (v)[0])
+#else
#define GETWORD(v)	(((v)[0] << 24) + ((v)[1] << 16) + ((v)[2] << 8) + (v)[3])
+#endif

#define isxdigit(c)	(('0' <= (c) && (c) <= '9') \
			 || ('a' <= (c) && (c) <= 'f') \

Philippe:  Wouldn't it be better to just do a 32-bit load and let the endianness be worked out
by the hardware?  i.e.

#define GETWORD(v) (*(u32 *)v)

Yes, your alternative is better.
Wouldn't it narrow the scope of the macro to aligned words on POWER7?
I think that all references to GETWORD operate on aligned words anyway.

Well, xmon has to be robust ... as long as you are *certain* that even
with crap entry state it won't try to access unaligned boundaries then
go for it but we aren't looking at performance here.

Cheers,
Ben.