diff options
Diffstat (limited to 'src/compiler/nir/nir_opt_undef.c')
| -rw-r--r-- | src/compiler/nir/nir_opt_undef.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/src/compiler/nir/nir_opt_undef.c b/src/compiler/nir/nir_opt_undef.c index 14459ff62af..ce18c2df043 100644 --- a/src/compiler/nir/nir_opt_undef.c +++ b/src/compiler/nir/nir_opt_undef.c @@ -25,18 +25,17 @@ /** @file nir_opt_undef.c * - * Handles optimization of operations involving ssa_undef. For now, we just - * make sure that csels between undef and some other value just give the other - * value (on the assumption that the condition's going to be choosing the - * defined value). This reduces work after if flattening when each side of - * the if is defining a variable. - * - * Some day, we may find some use for making other operations consuming an - * undef arg output undef, but I don't know of any cases currently. + * Handles optimization of operations involving ssa_undef. */ +/** + * Turn conditional selects between an undef and some other value into a move + * of that other value (on the assumption that the condition's going to be + * choosing the defined value). This reduces work after if flattening when + * each side of the if is defining a variable. + */ static bool -opt_undef_alu(nir_alu_instr *instr) +opt_undef_csel(nir_alu_instr *instr) { if (instr->op != nir_op_bcsel && instr->op != nir_op_fcsel) return false; @@ -80,9 +79,11 @@ nir_opt_undef(nir_shader *shader) if (function->impl) { nir_foreach_block(block, function->impl) { nir_foreach_instr_safe(instr, block) { - if (instr->type == nir_instr_type_alu) - if (opt_undef_alu(nir_instr_as_alu(instr))) - progress = true; + if (instr->type == nir_instr_type_alu) { + nir_alu_instr *alu = nir_instr_as_alu(instr); + + progress = opt_undef_csel(alu) || progress; + } } } |