<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body text="#000000" bgcolor="#FFFFFF"> <div class="moz-cite-prefix">On 4/23/19 5:16 PM, Jason Ekstrand wrote: </div> <blockquote type="cite" cite="mid:CAOFGe94RBM09CMhhYpe0cgTpdQdRDN3y2VmGwFExpXpWhuvW8w@mail.gmail.com"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <div dir="ltr"> <div class="gmail_quote"> <div dir="ltr" class="gmail_attr">On Tue, Apr 23, 2019 at 7:46 AM Samuel Pitoiset <<a href="mailto:samuel.pitoiset@gmail.com" moz-do-not-send="true">samuel.pitoiset@gmail.com</a>> wrote: </div> <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> On 4/23/19 10:45 AM, Bas Nieuwenhuizen wrote: > On Tue, Apr 23, 2019 at 9:35 AM Samuel Pitoiset > <<a href="mailto:samuel.pitoiset@gmail.com" target="_blank" moz-do-not-send="true">samuel.pitoiset@gmail.com</a>> wrote: >> Signed-off-by: Samuel Pitoiset <<a href="mailto:samuel.pitoiset@gmail.com" target="_blank" moz-do-not-send="true">samuel.pitoiset@gmail.com</a>> >> --- >> src/amd/vulkan/radv_shader.c | 2 +- >> src/compiler/nir/nir.h | 3 ++- >> src/compiler/nir/nir_opt_if.c | 17 ++++++++++------- >> src/freedreno/ir3/ir3_nir.c | 2 +- >> src/gallium/auxiliary/nir/tgsi_to_nir.c | 2 +- >> src/gallium/drivers/freedreno/a2xx/ir2_nir.c | 2 +- >> src/gallium/drivers/radeonsi/si_shader_nir.c | 2 +- >> src/intel/compiler/brw_nir.c | 2 +- >> src/mesa/state_tracker/st_glsl_to_nir.cpp | 2 +- >> 9 files changed, 19 insertions(+), 15 deletions(-) >> >> diff --git a/src/amd/vulkan/radv_shader.c b/src/amd/vulkan/radv_shader.c >> index 13f1f9aa9dc..54a4e732230 100644 >> --- a/src/amd/vulkan/radv_shader.c >> +++ b/src/amd/vulkan/radv_shader.c >> @@ -158,7 +158,7 @@ radv_optimize_nir(struct nir_shader *shader, bool optimize_conservatively, >> NIR_PASS(progress, shader, nir_opt_remove_phis); >> NIR_PASS(progress, shader, nir_opt_dce); >> } >> - NIR_PASS(progress, shader, nir_opt_if, true); >> + NIR_PASS(progress, shader, nir_opt_if, true, false); >> NIR_PASS(progress, shader, nir_opt_dead_cf); >> NIR_PASS(progress, shader, nir_opt_cse); >> NIR_PASS(progress, shader, nir_opt_peephole_select, 8, true, true); >> diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h >> index 7d2062d3691..d7506d6ddd1 100644 >> --- a/src/compiler/nir/nir.h >> +++ b/src/compiler/nir/nir.h >> @@ -3474,7 +3474,8 @@ bool nir_opt_gcm(nir_shader *shader, bool value_number); >> >> bool nir_opt_idiv_const(nir_shader *shader, unsigned min_bit_size); >> >> -bool nir_opt_if(nir_shader *shader, bool aggressive_last_continue); >> +bool nir_opt_if(nir_shader *shader, bool aggressive_last_continue, >> + bool skip_alu_of_phi); > Can we have a flag for this instead (e.g. something like > nir_opt_if_skip_alu_of_phi)? I think have a function with a bunch of > bools is less than ideal as you can't see at the calling site what is > for what arg. Yes, that seems better to me. </blockquote> <div> </div> <div>This is the worst kind of hack all around. We're making NIR more complicated and adding a flag to disable a useful and correct piece of an optimization, not because it causes a perf regression but because the back-end compiler is broken and this is easier than fixing it properly. Seriously? Can't we just fix the LLVM back-end? Or, if this optimization is actually doing something wrong, fix it? Or maybe actually figure out what pattern is causing LLVM to fall over and have a hack in your NIR -> LLVM pass? On the list of "good ways to fix this problem", this seems to be pretty far down if it hasn't fallen off the bottom. </div> </div> </div> </blockquote> Best hack of the month? :-) As discussed over IRC, this is definitely not the best solution, I don't like it either as I said. I will work on a different solution maybe in our NIR->LLVM pass. The aggressive_last_continue option should also be removed (make it default?). <blockquote type="cite" cite="mid:CAOFGe94RBM09CMhhYpe0cgTpdQdRDN3y2VmGwFExpXpWhuvW8w@mail.gmail.com"> <div dir="ltr"> <div class="gmail_quote"> <div> </div> <div>--Jason </div> <div> </div> <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> >> bool nir_opt_intrinsics(nir_shader *shader); >> >> diff --git a/src/compiler/nir/nir_opt_if.c b/src/compiler/nir/nir_opt_if.c >> index f674185f1e2..149b3bd1659 100644 >> --- a/src/compiler/nir/nir_opt_if.c >> +++ b/src/compiler/nir/nir_opt_if.c >> @@ -1385,7 +1385,8 @@ opt_if_cf_list(nir_builder *b, struct exec_list *cf_list, >> * not do anything to cause the metadata to become invalid. >> */ >> static bool >> -opt_if_safe_cf_list(nir_builder *b, struct exec_list *cf_list) >> +opt_if_safe_cf_list(nir_builder *b, struct exec_list *cf_list, >> + bool skip_alu_of_phi) >> { >> bool progress = false; >> foreach_list_typed(nir_cf_node, cf_node, node, cf_list) { >> @@ -1395,16 +1396,17 @@ opt_if_safe_cf_list(nir_builder *b, struct exec_list *cf_list) >> >> case nir_cf_node_if: { >> nir_if *nif = nir_cf_node_as_if(cf_node); >> - progress |= opt_if_safe_cf_list(b, &nif->then_list); >> - progress |= opt_if_safe_cf_list(b, &nif->else_list); >> + progress |= opt_if_safe_cf_list(b, &nif->then_list, skip_alu_of_phi); >> + progress |= opt_if_safe_cf_list(b, &nif->else_list, skip_alu_of_phi); >> progress |= opt_if_evaluate_condition_use(b, nif); >> break; >> } >> >> case nir_cf_node_loop: { >> nir_loop *loop = nir_cf_node_as_loop(cf_node); >> - progress |= opt_if_safe_cf_list(b, &loop->body); >> - progress |= opt_split_alu_of_phi(b, loop); >> + progress |= opt_if_safe_cf_list(b, &loop->body, skip_alu_of_phi); >> + if (!skip_alu_of_phi) >> + progress |= opt_split_alu_of_phi(b, loop); >> break; >> } >> >> @@ -1417,7 +1419,8 @@ opt_if_safe_cf_list(nir_builder *b, struct exec_list *cf_list) >> } >> >> bool >> -nir_opt_if(nir_shader *shader, bool aggressive_last_continue) >> +nir_opt_if(nir_shader *shader, bool aggressive_last_continue, >> + bool skip_alu_of_phi) >> { >> bool progress = false; >> >> @@ -1430,7 +1433,7 @@ nir_opt_if(nir_shader *shader, bool aggressive_last_continue) >> >> nir_metadata_require(function->impl, nir_metadata_block_index | >> nir_metadata_dominance); >> - progress = opt_if_safe_cf_list(&b, &function->impl->body); >> + progress = opt_if_safe_cf_list(&b, &function->impl->body, skip_alu_of_phi); >> nir_metadata_preserve(function->impl, nir_metadata_block_index | >> nir_metadata_dominance); >> >> diff --git a/src/freedreno/ir3/ir3_nir.c b/src/freedreno/ir3/ir3_nir.c >> index 76230e3be50..1bec3c030a9 100644 >> --- a/src/freedreno/ir3/ir3_nir.c >> +++ b/src/freedreno/ir3/ir3_nir.c >> @@ -147,7 +147,7 @@ ir3_optimize_loop(nir_shader *s) >> OPT(s, nir_copy_prop); >> OPT(s, nir_opt_dce); >> } >> - progress |= OPT(s, nir_opt_if, false); >> + progress |= OPT(s, nir_opt_if, false, false); >> progress |= OPT(s, nir_opt_remove_phis); >> progress |= OPT(s, nir_opt_undef); >> >> diff --git a/src/gallium/auxiliary/nir/tgsi_to_nir.c b/src/gallium/auxiliary/nir/tgsi_to_nir.c >> index c55e8b84a41..6b40bff1f73 100644 >> --- a/src/gallium/auxiliary/nir/tgsi_to_nir.c >> +++ b/src/gallium/auxiliary/nir/tgsi_to_nir.c >> @@ -2066,7 +2066,7 @@ ttn_optimize_nir(nir_shader *nir, bool scalar) >> NIR_PASS(progress, nir, nir_opt_dce); >> } >> >> - NIR_PASS(progress, nir, nir_opt_if, false); >> + NIR_PASS(progress, nir, nir_opt_if, false, false); >> NIR_PASS(progress, nir, nir_opt_dead_cf); >> NIR_PASS(progress, nir, nir_opt_cse); >> NIR_PASS(progress, nir, nir_opt_peephole_select, 8, true, true); >> diff --git a/src/gallium/drivers/freedreno/a2xx/ir2_nir.c b/src/gallium/drivers/freedreno/a2xx/ir2_nir.c >> index ee348ca6a93..3522971e435 100644 >> --- a/src/gallium/drivers/freedreno/a2xx/ir2_nir.c >> +++ b/src/gallium/drivers/freedreno/a2xx/ir2_nir.c >> @@ -94,7 +94,7 @@ ir2_optimize_loop(nir_shader *s) >> OPT(s, nir_opt_dce); >> } >> progress |= OPT(s, nir_opt_loop_unroll, nir_var_all); >> - progress |= OPT(s, nir_opt_if, false); >> + progress |= OPT(s, nir_opt_if, false, false); >> progress |= OPT(s, nir_opt_remove_phis); >> progress |= OPT(s, nir_opt_undef); >> >> diff --git a/src/gallium/drivers/radeonsi/si_shader_nir.c b/src/gallium/drivers/radeonsi/si_shader_nir.c >> index 5a925f19e09..7f1fe4ba2e9 100644 >> --- a/src/gallium/drivers/radeonsi/si_shader_nir.c >> +++ b/src/gallium/drivers/radeonsi/si_shader_nir.c >> @@ -879,7 +879,7 @@ si_lower_nir(struct si_shader_selector* sel) >> NIR_PASS(progress, sel->nir, nir_copy_prop); >> NIR_PASS(progress, sel->nir, nir_opt_dce); >> } >> - NIR_PASS(progress, sel->nir, nir_opt_if, true); >> + NIR_PASS(progress, sel->nir, nir_opt_if, true, false); >> 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, true, true); >> diff --git a/src/intel/compiler/brw_nir.c b/src/intel/compiler/brw_nir.c >> index e0a393fc298..ba911049ce3 100644 >> --- a/src/intel/compiler/brw_nir.c >> +++ b/src/intel/compiler/brw_nir.c >> @@ -607,7 +607,7 @@ brw_nir_optimize(nir_shader *nir, const struct brw_compiler *compiler, >> OPT(nir_copy_prop); >> OPT(nir_opt_dce); >> } >> - OPT(nir_opt_if, false); >> + OPT(nir_opt_if, false, false); >> if (nir->options->max_unroll_iterations != 0) { >> OPT(nir_opt_loop_unroll, indirect_mask); >> } >> diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp b/src/mesa/state_tracker/st_glsl_to_nir.cpp >> index 97b2831b880..3f1f78e875b 100644 >> --- a/src/mesa/state_tracker/st_glsl_to_nir.cpp >> +++ b/src/mesa/state_tracker/st_glsl_to_nir.cpp >> @@ -324,7 +324,7 @@ st_nir_opts(nir_shader *nir, bool scalar) >> NIR_PASS(progress, nir, nir_copy_prop); >> NIR_PASS(progress, nir, nir_opt_dce); >> } >> - NIR_PASS(progress, nir, nir_opt_if, false); >> + NIR_PASS(progress, nir, nir_opt_if, false, false); >> NIR_PASS(progress, nir, nir_opt_dead_cf); >> NIR_PASS(progress, nir, nir_opt_cse); >> NIR_PASS(progress, nir, nir_opt_peephole_select, 8, true, true); >> -- >> 2.21.0 >> >> _______________________________________________ >> mesa-dev mailing list >> <a href="mailto:mesa-dev@lists.freedesktop.org" target="_blank" moz-do-not-send="true">mesa-dev@lists.freedesktop.org</a> >> <a href="https://lists.freedesktop.org/mailman/listinfo/mesa-dev" rel="noreferrer" target="_blank" moz-do-not-send="true">https://lists.freedesktop.org/mailman/listinfo/mesa-dev</a> _______________________________________________ mesa-dev mailing list <a href="mailto:mesa-dev@lists.freedesktop.org" target="_blank" moz-do-not-send="true">mesa-dev@lists.freedesktop.org</a> <a href="https://lists.freedesktop.org/mailman/listinfo/mesa-dev" rel="noreferrer" target="_blank" moz-do-not-send="true">https://lists.freedesktop.org/mailman/listinfo/mesa-dev</a></blockquote> </div> </div> </blockquote> </body> </html>