From a406f7e0c9ab1ff36ae2d9fe377415bf41bace5a Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Tue, 20 Mar 2018 11:11:25 -0700 Subject: [PATCH] nir: Add a deref path helper struct This commit introduces a new nir_deref.h header for helpers that are less common and really only needed by a few heavy-duty passes. In this header is a new struct for representing a full deref path which can be walked in either direction. v2 (Jason Ekstrand): - Assert that deref != NULL (Caio) - Fill _short_path with 0xdeadbeef in debug builds when not used (Caio) - Make nir_deref_path a typedef (Rob) 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/Makefile.sources | 1 + src/compiler/nir/meson.build | 1 + src/compiler/nir/nir_deref.c | 57 +++++++++++++++++++++++++++++++++++ src/compiler/nir/nir_deref.h | 55 +++++++++++++++++++++++++++++++++ 4 files changed, 114 insertions(+) create mode 100644 src/compiler/nir/nir_deref.h diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources index 4206fb93b64..b59886afb92 100644 --- a/src/compiler/Makefile.sources +++ b/src/compiler/Makefile.sources @@ -208,6 +208,7 @@ NIR_FILES = \ nir/nir_control_flow.h \ nir/nir_control_flow_private.h \ nir/nir_deref.c \ + nir/nir_deref.h \ nir/nir_dominance.c \ nir/nir_format_convert.h \ nir/nir_from_ssa.c \ diff --git a/src/compiler/nir/meson.build b/src/compiler/nir/meson.build index 089a3787b8d..9d50782513e 100644 --- a/src/compiler/nir/meson.build +++ b/src/compiler/nir/meson.build @@ -93,6 +93,7 @@ files_libnir = files( 'nir_control_flow.h', 'nir_control_flow_private.h', 'nir_deref.c', + 'nir_deref.h', 'nir_dominance.c', 'nir_format_convert.h', 'nir_from_ssa.c', diff --git a/src/compiler/nir/nir_deref.c b/src/compiler/nir/nir_deref.c index 762b21833cf..4e48f2b2da8 100644 --- a/src/compiler/nir/nir_deref.c +++ b/src/compiler/nir/nir_deref.c @@ -23,6 +23,63 @@ #include "nir.h" #include "nir_builder.h" +#include "nir_deref.h" + +void +nir_deref_path_init(nir_deref_path *path, + nir_deref_instr *deref, void *mem_ctx) +{ + assert(deref != NULL); + + /* The length of the short path is at most ARRAY_SIZE - 1 because we need + * room for the NULL terminator. + */ + static const int max_short_path_len = ARRAY_SIZE(path->_short_path) - 1; + + int count = 0; + + nir_deref_instr **tail = &path->_short_path[max_short_path_len]; + nir_deref_instr **head = tail; + + *tail = NULL; + for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) { + count++; + if (count <= max_short_path_len) + *(--head) = d; + } + + if (count <= max_short_path_len) { + /* If we're under max_short_path_len, just use the short path. */ + path->path = head; + goto done; + } + +#ifndef NDEBUG + /* Just in case someone uses short_path by accident */ + for (unsigned i = 0; i < ARRAY_SIZE(path->_short_path); i++) + path->_short_path[i] = (void *)0xdeadbeef; +#endif + + path->path = ralloc_array(mem_ctx, nir_deref_instr *, count + 1); + head = tail = path->path + count; + *tail = NULL; + for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) + *(--head) = d; + +done: + assert(head == path->path); + assert(tail == head + count); + assert((*head)->deref_type == nir_deref_type_var); + assert(*tail == NULL); +} + +void +nir_deref_path_finish(nir_deref_path *path) +{ + if (path->path < &path->_short_path[0] || + path->path > &path->_short_path[ARRAY_SIZE(path->_short_path) - 1]) + ralloc_free(path->path); +} /** * Recursively removes unused deref instructions diff --git a/src/compiler/nir/nir_deref.h b/src/compiler/nir/nir_deref.h new file mode 100644 index 00000000000..0980bae7215 --- /dev/null +++ b/src/compiler/nir/nir_deref.h @@ -0,0 +1,55 @@ +/* + * Copyright © 2018 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#ifndef NIR_DEREF_H +#define NIR_DEREF_H + +#include "nir.h" +#include "nir_builder.h" + +#ifdef __cplusplus +extern "C" { +#endif + +typedef struct { + /** Short path so we can keep it on the stack most of the time. */ + nir_deref_instr *_short_path[7]; + + /** A null-terminated array view of a deref chain + * + * The first element of this array will be the variable dereference + * followed by every deref_instr on the path to the final one. The last + * element in the array is a NULL pointer which acts as a terminator. + */ + nir_deref_instr **path; +} nir_deref_path; + +void nir_deref_path_init(nir_deref_path *path, + nir_deref_instr *deref, void *mem_ctx); +void nir_deref_path_finish(nir_deref_path *path); + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif /* NIR_DEREF_H */ -- 2.30.2