Module: Mesa Branch: main Commit: 7e986e5f045a0e9da3ee64970a89d89907d0fcb4 URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=7e986e5f045a0e9da3ee64970a89d89907d0fcb4
Author: Emma Anholt <[email protected]> Date: Tue Sep 6 17:09:06 2022 -0700 nir/lower_mediump_vars: Don't lower mediump shared vars with atomic access. I don't know of any GPUs doing 16-bit atomic accesses, nor do I know of anybody wanting that in shaders. But deqp has GLES CTS cases that set mediump on shared variables, so just skip lowering for those vars. Reviewed-by: Matt Turner <[email protected]> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18452> --- src/compiler/nir/nir_lower_mediump.c | 50 +++++++++++++++++++++++++++++++++--- 1 file changed, 47 insertions(+), 3 deletions(-) diff --git a/src/compiler/nir/nir_lower_mediump.c b/src/compiler/nir/nir_lower_mediump.c index 2e8572c345b..7f870a6b3b1 100644 --- a/src/compiler/nir/nir_lower_mediump.c +++ b/src/compiler/nir/nir_lower_mediump.c @@ -387,11 +387,14 @@ is_mediump_or_lowp(unsigned precision) } static bool -try_lower_mediump_var(nir_variable *var, nir_variable_mode modes) +try_lower_mediump_var(nir_variable *var, nir_variable_mode modes, struct set *set) { if (!(var->data.mode & modes) || !is_mediump_or_lowp(var->data.precision)) return false; + if (set && _mesa_set_search(set, var)) + return false; + const struct glsl_type *new_type = glsl_type_to_16bit(var->type); if (var->type == new_type) return false; @@ -408,7 +411,7 @@ nir_lower_mediump_vars_impl(nir_function_impl *impl, nir_variable_mode modes, if (modes & nir_var_function_temp) { nir_foreach_function_temp_variable(var, impl) { - any_lowered = try_lower_mediump_var(var, modes) || any_lowered; + any_lowered = try_lower_mediump_var(var, modes, NULL) || any_lowered; } } if (!any_lowered) @@ -550,9 +553,50 @@ nir_lower_mediump_vars(nir_shader *shader, nir_variable_mode modes) bool progress = false; if (modes & ~nir_var_function_temp) { + /* Don't lower GLES mediump atomic ops to 16-bit -- no hardware is expecting that. */ + struct set *no_lower_set = _mesa_pointer_set_create(NULL); + nir_foreach_block(block, nir_shader_get_entrypoint(shader)) { + nir_foreach_instr(instr, block) { + if (instr->type != nir_instr_type_intrinsic) + continue; + nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); + switch (intr->intrinsic) { + case nir_intrinsic_deref_atomic_add: + case nir_intrinsic_deref_atomic_imin: + case nir_intrinsic_deref_atomic_umin: + case nir_intrinsic_deref_atomic_imax: + case nir_intrinsic_deref_atomic_umax: + case nir_intrinsic_deref_atomic_and: + case nir_intrinsic_deref_atomic_or: + case nir_intrinsic_deref_atomic_xor: + case nir_intrinsic_deref_atomic_exchange: + case nir_intrinsic_deref_atomic_fadd: + case nir_intrinsic_deref_atomic_fmin: + case nir_intrinsic_deref_atomic_fmax: + case nir_intrinsic_deref_atomic_comp_swap: + case nir_intrinsic_deref_atomic_fcomp_swap: { + nir_deref_instr *deref = nir_src_as_deref(intr->src[0]); + nir_variable *var = nir_deref_instr_get_variable(deref); + + /* If we have atomic derefs that we can't track, then don't lower any mediump. */ + if (!var) + return false; + + _mesa_set_add(no_lower_set, var); + break; + } + + default: + break; + } + } + } + nir_foreach_variable_in_shader(var, shader) { - progress = try_lower_mediump_var(var, modes) || progress; + progress = try_lower_mediump_var(var, modes, no_lower_set) || progress; } + + ralloc_free(no_lower_set); } nir_foreach_function(function, shader) {
