Why is this tagged as i965/fs, when everything seems to happen in the glsl-optimizer?
On Thu, Oct 24, 2013 at 5:53 PM, Eric Anholt <e...@anholt.net> wrote: > I noticed this in a shader in Unigine Heaven that was spilling. While it > doesn't really reduce register pressure, it shaves a few instructions > anyway (7955 -> 7882). > --- > src/glsl/opt_algebraic.cpp | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp > index 37b2f02..ff06cfc 100644 > --- a/src/glsl/opt_algebraic.cpp > +++ b/src/glsl/opt_algebraic.cpp > @@ -387,6 +387,14 @@ ir_algebraic_visitor::handle_expression(ir_expression > *ir) > } > break; > > + case ir_binop_rshift: > + case ir_binop_lshift: > + if (is_vec_zero(op_const[0])) > + return ir->operands[1]; > + else if (is_vec_zero(op_const[1])) > + return ir->operands[0]; > + break; > + Maybe update progress inside the conditionals also? But wait a minute. x shifted by 0 is x, so the latter part looks correct. But the first conditional seems to assume that 0 sifted by x is x, but it's really 0, no? Shouldn't both cases return ir->operands[0]? What am I missing? _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev