[PATCH 1/5] powerpc/lib/sstep: Add cmpb instruction emulation
segher at kernel.crashing.org
Thu Jul 13 17:10:46 AEST 2017
On Thu, Jul 13, 2017 at 01:43:53AM -0500, Segher Boessenkool wrote:
> On Thu, Jul 13, 2017 at 01:51:30PM +1000, Andrew Donnellan wrote:
> > On 13/07/17 13:25, Matt Brown wrote:
> > >@@ -1049,6 +1066,13 @@ int analyse_instr(struct instruction_op *op, struct
> > >pt_regs *regs,
> > > do_cmp_unsigned(regs, val, val2, rd >> 2);
> > > goto instr_done;
> > >
> > >+ case 19173952: /* cmpb */
> > This looks wrong and should never trigger, given that the switch
> > statement is comparing against ((instr >> 1) & 0x3ff).
> > How did you get this value?
> The correct number is 508, and 19173952 = 37744*508. How to get
> 37744 is a mystery though :-)
Ah. Take the binary representation of 508, and interpret that as if
it were octal :-) Those pesky meddling leading zeroes!
More information about the Linuxppc-dev