diff --git a/src/gallium/drivers/vc4/vc4_program.c b/src/gallium/drivers/vc4/vc4_program.c index e5f7aa31b0e..7d88444c673 100644 --- a/src/gallium/drivers/vc4/vc4_program.c +++ b/src/gallium/drivers/vc4/vc4_program.c @@ -2335,6 +2335,21 @@ vc4_shader_ntq(struct vc4_context *vc4, enum qstage stage, vc4_optimize_nir(c->s); + /* Do late algebraic optimization to turn add(a, neg(b)) back into + * subs, then the mandatory cleanup after algebraic. Note that it may + * produce fnegs, and if so then we need to keep running to squash + * fneg(fneg(a)). + */ + bool more_late_algebraic = true; + while (more_late_algebraic) { + more_late_algebraic = false; + NIR_PASS(more_late_algebraic, c->s, nir_opt_algebraic_late); + NIR_PASS_V(c->s, nir_opt_constant_folding); + NIR_PASS_V(c->s, nir_copy_prop); + NIR_PASS_V(c->s, nir_opt_dce); + NIR_PASS_V(c->s, nir_opt_cse); + } + NIR_PASS_V(c->s, nir_lower_bool_to_int32); NIR_PASS_V(c->s, nir_convert_from_ssa, true);