Re: [RFC] "single step" atomic instruction sequences as a whole on PPC

Ulrich Weigand
2007-05-09T14:33:30Z

Luis Machado wrote:

Actually, I think there's still a problem with the patch. Sorry for
not noticing earlier. You call:

> +#define BC_INSTRUCTION 0x40000000
> + const int opcode = BC_INSTRUCTION; /* Branch instruction's OPcode. */
> + branch_bp = branch_dest (opcode, insn, pc, breaks[0]);

branch_dest with 0x40000000 as opcode -- however, it appears the
routine expects to be called with just the opcode bits, i.e. 16
in the case of a conditional branch.

See the call in rs6000_software_single_step:
> opcode = insn >> 26;
> breaks[1] = branch_dest (opcode, insn, loc, breaks[0]);

Could you implement and test a patch to fix this, please?

Thanks,
Ulrich

--
Dr. Ulrich Weigand
GNU Toolchain for Linux on System z and Cell BE
Ulrich.Weigand@de.ibm.com