From 4a4e1757381c65653fd6a81cf4e969ddff926ed5 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Fri, 16 Mar 2018 00:20:57 -0700 Subject: [PATCH] nir: Support deref instructions in lower_var_copies Reviewed-by: Caio Marcelo de Oliveira Filho Acked-by: Rob Clark Acked-by: Bas Nieuwenhuizen Acked-by: Dave Airlie Reviewed-by: Kenneth Graunke --- src/compiler/nir/nir.h | 3 + src/compiler/nir/nir_builder.h | 48 ++++++++++++ src/compiler/nir/nir_lower_var_copies.c | 97 +++++++++++++++++++++++-- 3 files changed, 143 insertions(+), 5 deletions(-) diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 3ba2ddfeb02..99ec43c1778 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -78,6 +78,7 @@ name(const in_type *parent) \ struct nir_function; struct nir_shader; struct nir_instr; +struct nir_builder; /** @@ -2699,6 +2700,8 @@ bool nir_lower_deref_instrs(nir_shader *shader, enum nir_lower_deref_flags flags); void nir_lower_var_copy_instr(nir_intrinsic_instr *copy, nir_shader *shader); +void nir_lower_deref_copy_instr(struct nir_builder *b, + nir_intrinsic_instr *copy); bool nir_lower_var_copies(nir_shader *shader); void nir_fixup_deref_modes(nir_shader *shader); diff --git a/src/compiler/nir/nir_builder.h b/src/compiler/nir/nir_builder.h index 42fe285506e..da7a501fa85 100644 --- a/src/compiler/nir/nir_builder.h +++ b/src/compiler/nir/nir_builder.h @@ -667,6 +667,54 @@ nir_build_deref_for_chain(nir_builder *b, nir_deref_var *deref_var) return tail; } +/** Returns a deref that follows another but starting from the given parent + * + * The new deref will be the same type and take the same array or struct index + * as the leader deref but it may have a different parent. This is very + * useful for walking deref paths. + */ +static inline nir_deref_instr * +nir_build_deref_follower(nir_builder *b, nir_deref_instr *parent, + nir_deref_instr *leader) +{ + /* If the derefs would have the same parent, don't make a new one */ + assert(leader->parent.is_ssa); + if (leader->parent.ssa == &parent->dest.ssa) + return leader; + + UNUSED nir_deref_instr *leader_parent = nir_src_as_deref(leader->parent); + + switch (leader->deref_type) { + case nir_deref_type_var: + unreachable("A var dereference cannot have a parent"); + break; + + case nir_deref_type_array: + case nir_deref_type_array_wildcard: + assert(glsl_type_is_matrix(parent->type) || + glsl_type_is_array(parent->type)); + assert(glsl_get_length(parent->type) == + glsl_get_length(leader_parent->type)); + + if (leader->deref_type == nir_deref_type_array) { + assert(leader->arr.index.is_ssa); + return nir_build_deref_array(b, parent, leader->arr.index.ssa); + } else { + return nir_build_deref_array_wildcard(b, parent); + } + + case nir_deref_type_struct: + assert(glsl_type_is_struct(parent->type)); + assert(glsl_get_length(parent->type) == + glsl_get_length(leader_parent->type)); + + return nir_build_deref_struct(b, parent, leader->strct.index); + + default: + unreachable("Invalid deref instruction type"); + } +} + static inline nir_ssa_def * nir_load_reg(nir_builder *build, nir_register *reg) { diff --git a/src/compiler/nir/nir_lower_var_copies.c b/src/compiler/nir/nir_lower_var_copies.c index e7b2bd5a236..227d46747f1 100644 --- a/src/compiler/nir/nir_lower_var_copies.c +++ b/src/compiler/nir/nir_lower_var_copies.c @@ -26,6 +26,8 @@ */ #include "nir.h" +#include "nir_builder.h" +#include "nir_deref.h" #include "compiler/nir_types.h" /* @@ -154,24 +156,111 @@ nir_lower_var_copy_instr(nir_intrinsic_instr *copy, nir_shader *shader) ©->variables[1]->deref, shader); } +static nir_deref_instr * +build_deref_to_next_wildcard(nir_builder *b, + nir_deref_instr *parent, + nir_deref_instr ***deref_arr) +{ + for (; **deref_arr; (*deref_arr)++) { + if ((**deref_arr)->deref_type == nir_deref_type_array_wildcard) + return parent; + + parent = nir_build_deref_follower(b, parent, **deref_arr); + } + + assert(**deref_arr == NULL); + *deref_arr = NULL; + return parent; +} + +static void +emit_deref_copy_load_store(nir_builder *b, + nir_deref_instr *dst_deref, + nir_deref_instr **dst_deref_arr, + nir_deref_instr *src_deref, + nir_deref_instr **src_deref_arr) +{ + if (dst_deref_arr || src_deref_arr) { + assert(dst_deref_arr && src_deref_arr); + dst_deref = build_deref_to_next_wildcard(b, dst_deref, &dst_deref_arr); + src_deref = build_deref_to_next_wildcard(b, src_deref, &src_deref_arr); + } + + if (dst_deref_arr || src_deref_arr) { + assert(dst_deref_arr && src_deref_arr); + assert((*dst_deref_arr)->deref_type == nir_deref_type_array_wildcard); + assert((*src_deref_arr)->deref_type == nir_deref_type_array_wildcard); + + unsigned length = glsl_get_length(src_deref->type); + /* The wildcards should represent the same number of elements */ + assert(length == glsl_get_length(dst_deref->type)); + assert(length > 0); + + for (unsigned i = 0; i < length; i++) { + nir_ssa_def *index = nir_imm_int(b, i); + emit_deref_copy_load_store(b, + nir_build_deref_array(b, dst_deref, index), + dst_deref_arr + 1, + nir_build_deref_array(b, src_deref, index), + src_deref_arr + 1); + } + } else { + assert(dst_deref->type == src_deref->type); + assert(glsl_type_is_vector_or_scalar(dst_deref->type)); + + nir_store_deref(b, dst_deref, nir_load_deref(b, src_deref), ~0); + } +} + +void +nir_lower_deref_copy_instr(nir_builder *b, nir_intrinsic_instr *copy) +{ + /* Unfortunately, there's just no good way to handle wildcards except to + * flip the chain around and walk the list from variable to final pointer. + */ + assert(copy->src[0].is_ssa && copy->src[1].is_ssa); + nir_deref_instr *dst = nir_instr_as_deref(copy->src[0].ssa->parent_instr); + nir_deref_instr *src = nir_instr_as_deref(copy->src[1].ssa->parent_instr); + + nir_deref_path dst_path, src_path; + nir_deref_path_init(&dst_path, dst, NULL); + nir_deref_path_init(&src_path, src, NULL); + + b->cursor = nir_before_instr(©->instr); + emit_deref_copy_load_store(b, dst_path.path[0], &dst_path.path[1], + src_path.path[0], &src_path.path[1]); + + nir_deref_path_finish(&dst_path); + nir_deref_path_finish(&src_path); +} + static bool lower_var_copies_impl(nir_function_impl *impl) { nir_shader *shader = impl->function->shader; bool progress = false; + nir_builder b; + nir_builder_init(&b, impl); + nir_foreach_block(block, impl) { nir_foreach_instr_safe(instr, block) { if (instr->type != nir_instr_type_intrinsic) continue; nir_intrinsic_instr *copy = nir_instr_as_intrinsic(instr); - if (copy->intrinsic != nir_intrinsic_copy_var) + if (copy->intrinsic == nir_intrinsic_copy_var) + nir_lower_var_copy_instr(copy, shader); + else if (copy->intrinsic == nir_intrinsic_copy_deref) + nir_lower_deref_copy_instr(&b, copy); + else continue; - nir_lower_var_copy_instr(copy, shader); - nir_instr_remove(©->instr); + if (copy->intrinsic == nir_intrinsic_copy_deref) { + nir_deref_instr_remove_if_unused(nir_src_as_deref(copy->src[0])); + nir_deref_instr_remove_if_unused(nir_src_as_deref(copy->src[1])); + } progress = true; ralloc_free(copy); } @@ -192,8 +281,6 @@ nir_lower_var_copies(nir_shader *shader) { bool progress = false; - nir_assert_lowered_derefs(shader, nir_lower_load_store_derefs); - nir_foreach_function(function, shader) { if (function->impl) progress |= lower_var_copies_impl(function->impl); -- 2.30.2