nir: allow propagation of if evaluation for bcsel

Shader-db results Skylake:

total instructions in shared programs: 13109035 -> 13109024 (<.01%)
instructions in affected programs: 4777 -> 4766 (-0.23%)
helped: 11
HURT: 0

total cycles in shared programs: 332090418 -> 332090443 (<.01%)
cycles in affected programs: 19474 -> 19499 (0.13%)
helped: 6
HURT: 4

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
This commit is contained in:
Timothy Arceri 2018-11-02 08:53:16 +11:00 committed by Timothy Arceri
parent 677b496b6b
commit c7bdda8aa5

View file

@ -448,7 +448,7 @@ propagate_condition_eval(nir_builder *b, nir_if *nif, nir_src *use_src,
if (!evaluate_if_condition(nif, b->cursor, &bool_value)) if (!evaluate_if_condition(nif, b->cursor, &bool_value))
return false; return false;
nir_ssa_def *def[2] = {0}; nir_ssa_def *def[4] = {0};
for (unsigned i = 0; i < nir_op_infos[alu->op].num_inputs; i++) { for (unsigned i = 0; i < nir_op_infos[alu->op].num_inputs; i++) {
if (alu->src[i].src.ssa == use_src->ssa) { if (alu->src[i].src.ssa == use_src->ssa) {
def[i] = nir_imm_bool(b, bool_value); def[i] = nir_imm_bool(b, bool_value);
@ -456,7 +456,7 @@ propagate_condition_eval(nir_builder *b, nir_if *nif, nir_src *use_src,
def[i] = alu->src[i].src.ssa; def[i] = alu->src[i].src.ssa;
} }
} }
nir_ssa_def *nalu = nir_build_alu(b, alu->op, def[0], def[1], NULL, NULL); nir_ssa_def *nalu = nir_build_alu(b, alu->op, def[0], def[1], def[2], def[3]);
/* Rewrite use to use new alu instruction */ /* Rewrite use to use new alu instruction */
nir_src new_src = nir_src_for_ssa(nalu); nir_src new_src = nir_src_for_ssa(nalu);
@ -472,14 +472,21 @@ propagate_condition_eval(nir_builder *b, nir_if *nif, nir_src *use_src,
static bool static bool
can_propagate_through_alu(nir_src *src) can_propagate_through_alu(nir_src *src)
{ {
if (src->parent_instr->type == nir_instr_type_alu && if (src->parent_instr->type != nir_instr_type_alu)
(nir_instr_as_alu(src->parent_instr)->op == nir_op_ior || return false;
nir_instr_as_alu(src->parent_instr)->op == nir_op_iand ||
nir_instr_as_alu(src->parent_instr)->op == nir_op_inot ||
nir_instr_as_alu(src->parent_instr)->op == nir_op_b2i))
return true;
return false; nir_alu_instr *alu = nir_instr_as_alu(src->parent_instr);
switch (alu->op) {
case nir_op_ior:
case nir_op_iand:
case nir_op_inot:
case nir_op_b2i:
return true;
case nir_op_bcsel:
return src == &alu->src[0].src;
default:
return false;
}
} }
static bool static bool