On 23/07/18 18:02, Timothy Arceri wrote:
Since we know what side of the branch we ended up on we can just replace the use with a constant.All the spill changes in shader-db are from Dolphin uber shaders, despite some small regressions the change is clearly positive. shader-db results IVB: total instructions in shared programs: 9999201 -> 9993483 (-0.06%) instructions in affected programs: 163235 -> 157517 (-3.50%) helped: 132 HURT: 2 total cycles in shared programs: 231670754 -> 219476091 (-5.26%) cycles in affected programs: 143424120 -> 131229457 (-8.50%) helped: 115 HURT: 24 total spills in shared programs: 4383 -> 4370 (-0.30%) spills in affected programs: 1656 -> 1643 (-0.79%) helped: 9 HURT: 18 total fills in shared programs: 4610 -> 4581 (-0.63%) fills in affected programs: 374 -> 345 (-7.75%) helped: 6 HURT: 0 --- src/compiler/nir/nir_opt_if.c | 124 ++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) diff --git a/src/compiler/nir/nir_opt_if.c b/src/compiler/nir/nir_opt_if.c index b3d0bf1decb..b3d5046a76e 100644 --- a/src/compiler/nir/nir_opt_if.c +++ b/src/compiler/nir/nir_opt_if.c @@ -369,6 +369,87 @@ opt_if_loop_terminator(nir_if *nif) return true; }+static void+replace_if_condition_use_with_const(nir_src *use, unsigned nir_boolean, + void *mem_ctx, bool if_condition) +{ + /* Create const */ + nir_load_const_instr *load = nir_load_const_instr_create(mem_ctx, 1, 32); + load->value.u32[0] = nir_boolean; + + if (if_condition) { + nir_instr_insert_before_cf(&use->parent_if->cf_node, &load->instr); + } else if (use->parent_instr->type == nir_instr_type_phi) { + nir_phi_instr *cond_phi = nir_instr_as_phi(use->parent_instr); + + bool UNUSED found = false; + nir_foreach_phi_src(phi_src, cond_phi) { + if (phi_src->src.ssa == use->ssa) { + nir_instr_insert_before_block(phi_src->pred, &load->instr);
I've just noticed this needs to be nir_instr_insert_after_block() otherwise we can end up inserting the const before so other phi which trips up validation.
I've fixed this locally. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
