On Fri, Mar 13, 2015 at 10:35 AM, Matt Turner <matts...@gmail.com> wrote: > On Fri, Mar 13, 2015 at 6:20 AM, Tapani Pälli <tapani.pa...@intel.com> wrote: >> Commit bb33a31 introduced MAD->MUL optimization which did not >> take account case where one of the remaining sources is immediate >> and did not report progress. Patch changes last one of the sources >> to be immediate and adds progress reporting. If both are, this is >> taken care of by the same opt_algebraic pass on later run. >> >> Signed-off-by: Tapani Pälli <tapani.pa...@intel.com> >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89569 >> --- >> src/mesa/drivers/dri/i965/brw_fs.cpp | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp >> b/src/mesa/drivers/dri/i965/brw_fs.cpp >> index 8702ea8..710a7e6 100644 >> --- a/src/mesa/drivers/dri/i965/brw_fs.cpp >> +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp >> @@ -2490,7 +2490,14 @@ fs_visitor::opt_algebraic() >> } else if (inst->src[0].is_zero()) { >> inst->opcode = BRW_OPCODE_MUL; >> inst->src[0] = inst->src[2]; >> + /* Last one needs to be immediate. */ >> + if (inst->src[0].file == IMM) { >> + inst->src[2] = inst->src[1]; >> + inst->src[1] = inst->src[0]; >> + inst->src[0] = inst->src[2]; >> + } > > To confirm, we had a MAD dst, 0.0, x, y, and we transform it here into > MUL dst, x, y. But x is actually an immediate and since we didn't > report progress (and nothing else did in the optimization loop), we > attempt to make an illegal instruction. > > Nice find! > > I might add something like this to the commit message. > > Doesn't this problem exist for other cases too? The next two, checking > for 1.0 multiplicand arguments, seem to have the same problem. > > Could you fix those at the same time? > > Thanks Tapani & Curro!
Ken was telling me today that he independently ran into this and had some different idea about fixing it. Adding him to Cc. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
