nir/opt_peephole_select: Don't try to remove flow control around indirect loads
That flow control may be trying to avoid invalid loads. On at least some platforms, those loads can also be expensive. No shader-db changes on any Intel platform (even with the later patch "intel/compiler: More peephole select"). v2: Add a 'indirect_load_ok' flag to nir_opt_peephole_select. Suggested by Rob. See also the big comment in src/intel/compiler/brw_nir.c. v3: Use nir_deref_instr_has_indirect instead of deref_has_indirect (from nir_lower_io_arrays_to_elements.c). v4: Fix inverted condition in brw_nir.c. Noticed by Lionel. Signed-off-by: Ian Romanick <ian.d.romanick@intel.com> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
This commit is contained in:
@@ -159,7 +159,7 @@ radv_optimize_nir(struct nir_shader *shader, bool optimize_conservatively,
|
||||
NIR_PASS(progress, shader, nir_opt_if);
|
||||
NIR_PASS(progress, shader, nir_opt_dead_cf);
|
||||
NIR_PASS(progress, shader, nir_opt_cse);
|
||||
NIR_PASS(progress, shader, nir_opt_peephole_select, 8);
|
||||
NIR_PASS(progress, shader, nir_opt_peephole_select, 8, true);
|
||||
NIR_PASS(progress, shader, nir_opt_algebraic);
|
||||
NIR_PASS(progress, shader, nir_opt_constant_folding);
|
||||
NIR_PASS(progress, shader, nir_opt_undef);
|
||||
|
@@ -1241,7 +1241,7 @@ v3d_optimize_nir(struct nir_shader *s)
|
||||
NIR_PASS(progress, s, nir_opt_dce);
|
||||
NIR_PASS(progress, s, nir_opt_dead_cf);
|
||||
NIR_PASS(progress, s, nir_opt_cse);
|
||||
NIR_PASS(progress, s, nir_opt_peephole_select, 8);
|
||||
NIR_PASS(progress, s, nir_opt_peephole_select, 8, true);
|
||||
NIR_PASS(progress, s, nir_opt_algebraic);
|
||||
NIR_PASS(progress, s, nir_opt_constant_folding);
|
||||
NIR_PASS(progress, s, nir_opt_undef);
|
||||
|
@@ -3197,7 +3197,8 @@ bool nir_opt_move_comparisons(nir_shader *shader);
|
||||
|
||||
bool nir_opt_move_load_ubo(nir_shader *shader);
|
||||
|
||||
bool nir_opt_peephole_select(nir_shader *shader, unsigned limit);
|
||||
bool nir_opt_peephole_select(nir_shader *shader, unsigned limit,
|
||||
bool indirect_load_ok);
|
||||
|
||||
bool nir_opt_remove_phis_impl(nir_function_impl *impl);
|
||||
bool nir_opt_remove_phis(nir_shader *shader);
|
||||
|
@@ -58,7 +58,8 @@
|
||||
*/
|
||||
|
||||
static bool
|
||||
block_check_for_allowed_instrs(nir_block *block, unsigned *count, bool alu_ok)
|
||||
block_check_for_allowed_instrs(nir_block *block, unsigned *count,
|
||||
bool alu_ok, bool indirect_load_ok)
|
||||
{
|
||||
nir_foreach_instr(instr, block) {
|
||||
switch (instr->type) {
|
||||
@@ -66,16 +67,26 @@ block_check_for_allowed_instrs(nir_block *block, unsigned *count, bool alu_ok)
|
||||
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
|
||||
|
||||
switch (intrin->intrinsic) {
|
||||
case nir_intrinsic_load_deref:
|
||||
switch (nir_src_as_deref(intrin->src[0])->mode) {
|
||||
case nir_intrinsic_load_deref: {
|
||||
nir_deref_instr *const deref = nir_src_as_deref(intrin->src[0]);
|
||||
|
||||
switch (deref->mode) {
|
||||
case nir_var_shader_in:
|
||||
case nir_var_uniform:
|
||||
/* Don't try to remove flow control around an indirect load
|
||||
* because that flow control may be trying to avoid invalid
|
||||
* loads.
|
||||
*/
|
||||
if (!indirect_load_ok && nir_deref_instr_has_indirect(deref))
|
||||
return false;
|
||||
|
||||
break;
|
||||
|
||||
default:
|
||||
return false;
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
case nir_intrinsic_load_uniform:
|
||||
if (!alu_ok)
|
||||
@@ -149,7 +160,7 @@ block_check_for_allowed_instrs(nir_block *block, unsigned *count, bool alu_ok)
|
||||
|
||||
static bool
|
||||
nir_opt_peephole_select_block(nir_block *block, nir_shader *shader,
|
||||
unsigned limit)
|
||||
unsigned limit, bool indirect_load_ok)
|
||||
{
|
||||
if (nir_cf_node_is_first(&block->cf_node))
|
||||
return false;
|
||||
@@ -169,8 +180,10 @@ nir_opt_peephole_select_block(nir_block *block, nir_shader *shader,
|
||||
|
||||
/* ... and those blocks must only contain "allowed" instructions. */
|
||||
unsigned count = 0;
|
||||
if (!block_check_for_allowed_instrs(then_block, &count, limit != 0) ||
|
||||
!block_check_for_allowed_instrs(else_block, &count, limit != 0))
|
||||
if (!block_check_for_allowed_instrs(then_block, &count, limit != 0,
|
||||
indirect_load_ok) ||
|
||||
!block_check_for_allowed_instrs(else_block, &count, limit != 0,
|
||||
indirect_load_ok))
|
||||
return false;
|
||||
|
||||
if (count > limit)
|
||||
@@ -236,13 +249,15 @@ nir_opt_peephole_select_block(nir_block *block, nir_shader *shader,
|
||||
}
|
||||
|
||||
static bool
|
||||
nir_opt_peephole_select_impl(nir_function_impl *impl, unsigned limit)
|
||||
nir_opt_peephole_select_impl(nir_function_impl *impl, unsigned limit,
|
||||
bool indirect_load_ok)
|
||||
{
|
||||
nir_shader *shader = impl->function->shader;
|
||||
bool progress = false;
|
||||
|
||||
nir_foreach_block_safe(block, impl) {
|
||||
progress |= nir_opt_peephole_select_block(block, shader, limit);
|
||||
progress |= nir_opt_peephole_select_block(block, shader, limit,
|
||||
indirect_load_ok);
|
||||
}
|
||||
|
||||
if (progress)
|
||||
@@ -252,13 +267,15 @@ nir_opt_peephole_select_impl(nir_function_impl *impl, unsigned limit)
|
||||
}
|
||||
|
||||
bool
|
||||
nir_opt_peephole_select(nir_shader *shader, unsigned limit)
|
||||
nir_opt_peephole_select(nir_shader *shader, unsigned limit,
|
||||
bool indirect_load_ok)
|
||||
{
|
||||
bool progress = false;
|
||||
|
||||
nir_foreach_function(function, shader) {
|
||||
if (function->impl)
|
||||
progress |= nir_opt_peephole_select_impl(function->impl, limit);
|
||||
progress |= nir_opt_peephole_select_impl(function->impl, limit,
|
||||
indirect_load_ok);
|
||||
}
|
||||
|
||||
return progress;
|
||||
|
@@ -97,7 +97,7 @@ ir3_optimize_loop(nir_shader *s)
|
||||
progress |= OPT(s, nir_opt_gcm, true);
|
||||
else if (gcm == 2)
|
||||
progress |= OPT(s, nir_opt_gcm, false);
|
||||
progress |= OPT(s, nir_opt_peephole_select, 16);
|
||||
progress |= OPT(s, nir_opt_peephole_select, 16, true);
|
||||
progress |= OPT(s, nir_opt_intrinsics);
|
||||
progress |= OPT(s, nir_opt_algebraic);
|
||||
progress |= OPT(s, nir_opt_constant_folding);
|
||||
|
@@ -841,7 +841,7 @@ si_lower_nir(struct si_shader_selector* sel)
|
||||
NIR_PASS(progress, sel->nir, nir_opt_if);
|
||||
NIR_PASS(progress, sel->nir, nir_opt_dead_cf);
|
||||
NIR_PASS(progress, sel->nir, nir_opt_cse);
|
||||
NIR_PASS(progress, sel->nir, nir_opt_peephole_select, 8);
|
||||
NIR_PASS(progress, sel->nir, nir_opt_peephole_select, 8, true);
|
||||
|
||||
/* Needed for algebraic lowering */
|
||||
NIR_PASS(progress, sel->nir, nir_opt_algebraic);
|
||||
|
@@ -1591,7 +1591,7 @@ vc4_optimize_nir(struct nir_shader *s)
|
||||
NIR_PASS(progress, s, nir_opt_dce);
|
||||
NIR_PASS(progress, s, nir_opt_dead_cf);
|
||||
NIR_PASS(progress, s, nir_opt_cse);
|
||||
NIR_PASS(progress, s, nir_opt_peephole_select, 8);
|
||||
NIR_PASS(progress, s, nir_opt_peephole_select, 8, true);
|
||||
NIR_PASS(progress, s, nir_opt_algebraic);
|
||||
NIR_PASS(progress, s, nir_opt_constant_folding);
|
||||
NIR_PASS(progress, s, nir_opt_undef);
|
||||
|
@@ -568,7 +568,18 @@ brw_nir_optimize(nir_shader *nir, const struct brw_compiler *compiler,
|
||||
OPT(nir_copy_prop);
|
||||
OPT(nir_opt_dce);
|
||||
OPT(nir_opt_cse);
|
||||
OPT(nir_opt_peephole_select, 0);
|
||||
|
||||
/* For indirect loads of uniforms (push constants), we assume that array
|
||||
* indices will nearly always be in bounds and the cost of the load is
|
||||
* low. Therefore there shouldn't be a performance benefit to avoid it.
|
||||
* However, in vec4 tessellation shaders, these loads operate by
|
||||
* actually pulling from memory.
|
||||
*/
|
||||
const bool is_vec4_tessellation = !is_scalar &&
|
||||
(nir->info.stage == MESA_SHADER_TESS_CTRL ||
|
||||
nir->info.stage == MESA_SHADER_TESS_EVAL);
|
||||
OPT(nir_opt_peephole_select, 0, !is_vec4_tessellation);
|
||||
|
||||
OPT(nir_opt_intrinsics);
|
||||
OPT(nir_opt_idiv_const, 32);
|
||||
OPT(nir_opt_algebraic);
|
||||
|
@@ -328,7 +328,7 @@ st_nir_opts(nir_shader *nir, bool scalar)
|
||||
NIR_PASS(progress, nir, nir_opt_if);
|
||||
NIR_PASS(progress, nir, nir_opt_dead_cf);
|
||||
NIR_PASS(progress, nir, nir_opt_cse);
|
||||
NIR_PASS(progress, nir, nir_opt_peephole_select, 8);
|
||||
NIR_PASS(progress, nir, nir_opt_peephole_select, 8, true);
|
||||
|
||||
NIR_PASS(progress, nir, nir_opt_algebraic);
|
||||
NIR_PASS(progress, nir, nir_opt_constant_folding);
|
||||
|
Reference in New Issue
Block a user