On Mon, Apr 06, 2020 at 12:25:27PM +0200, Christophe Leroy wrote:

quoted

if (ppc_inst_prefixed(x) != ppc_inst_prefixed(y))
	return false;
else if (ppc_inst_prefixed(x))
	return !memcmp(&x, &y, sizeof(struct ppc_inst));

Are we sure memcmp() is a good candidate for the comparison ? Can we do 
simpler ? Especially, I understood a prefixed instruction is a 64 bits 
properly aligned instruction, can we do a simple u64 compare ? Or is GCC 
intelligent enough to do that without calling memcmp() function which is 
heavy ?

A prefixed insn is *not* 8-byte aligned, it is 4-byte aligned, fwiw.

memcmp() isn't as heavy as you fear, not with a non-ancient GCC at least.
But this could be written in a nicer way, sure :-)


Segher