This is the third iteration of a patch to resolve a strict aliasing
problem in the exec_list structure.
At the suggestion of Francisco Jerez this is a return to the original
(v1) style of the patch, which replaces the three 'exec_node *' members
in the list with two 'struct exec_node' members.
Some performance/memory measurements (made by replaying a Dota 2 trace,
using i965 driver with INTEL_NO_HW=1). All values are averages over 5
runs. "MRSS" is maximum resident set size as reported by GNU "time" (I'm
not sure I trust its value, but I believe it's indicative of relative
memory use). "user time" is included to show the actual processor time
consumption; it is arguably a better measure of performance than the
FPS. Measurements made on x86-32.
Order going left to right:
(without patch), (with this patch), (with this patch and strict aliasing
enabled), (with V2 patch), (with V2 patch and strict aliasing).
FPS: 10.0788 9.8358 10.0511 9.9928 10.0547
User time (s): 42.142 42.904 42.286 42.416 42.206
MRSS (M): 2772 2828 2827 2814 2814
So, there is ever-so-slight performance decrease when the patch is
applied but the lost performance is mostly recovered by removing
-fno-strict-aliasing from the compiler flags. (It is difficult to
understand why V2 in particular has any performance degradation at all;
I suspect the compiler isn't doing as good a job as it could. I'm using
GCC 4.8.4 with "-O3 -fomit-frame-pointer -march=corei7").
V2 and V3 of the patch are comparable in performance. V3 (this one) uses
more memory due to the increase in size of the exec_list structure, but
is arguably cleaner code.
Original description:
There is a problem in exec_list due to it directly including a trio
of 'struct exec_node *' members to implement two overlapping sentinel
nodes. The sentinel nodes do not exist as exec_node objects and so
should not be accessed as such, according to C99 6.5 paragraph 7.
When this strict aliasing rule is violated the compiler may re-order
reads and writes in unexpected ways. The problem only manifests if
compiling without -fno-strict-aliasing, since that option allows
breaking the strict aliasing rules.
This patch addresses the issue by including explicit head and tail
sentinel nodes into the exec_list structure, which do not overlap.
This adds a single word of storage to the size of the exec_list structure.
While I'm not proposing that -fno-strict-aliasing no longer be used for
Mesa builds, this patch represents a step in that direction. With this
patch applied, a working Mesa library can be built, although bugs may
be present (and could be triggered only when using particular compiler
versions and options on particular platforms).
---
src/glsl/ast_function.cpp | 20 +++--
src/glsl/ast_to_hir.cpp | 9 +-
src/glsl/glsl_parser_extras.cpp | 6 +-
src/glsl/ir.cpp | 8 +-
src/glsl/ir_clone.cpp | 2 +-
src/glsl/ir_constant_expression.cpp | 3 +-
src/glsl/ir_function.cpp | 14 ++--
src/glsl/ir_reader.cpp | 5 +-
src/glsl/ir_validate.cpp | 5 +-
src/glsl/list.h | 130
+++++++++++++----------------
src/glsl/lower_clip_distance.cpp | 6 +-
src/glsl/lower_jumps.cpp | 2 +-
src/glsl/lower_packed_varyings.cpp | 8 +-
src/glsl/nir/nir.c | 6 +-
src/glsl/nir/nir_opt_gcm.c | 2 +-
src/glsl/opt_conditional_discard.cpp | 8 +-
src/glsl/opt_constant_variable.cpp | 3 +-
src/glsl/opt_dead_builtin_varyings.cpp | 2 +-
src/glsl/opt_flatten_nested_if_blocks.cpp | 3 +-
src/mesa/drivers/dri/i965/brw_cfg.h | 12 +--
src/mesa/drivers/dri/i965/brw_fs_builder.h | 2 +-
21 files changed, 130 insertions(+), 126 deletions(-)
diff --git a/src/glsl/ast_function.cpp b/src/glsl/ast_function.cpp
index 92e26bf..348e615 100644
--- a/src/glsl/ast_function.cpp
+++ b/src/glsl/ast_function.cpp
@@ -152,8 +152,8 @@ verify_parameter_modes(_mesa_glsl_parse_state *state,
exec_list &actual_ir_parameters,
exec_list &actual_ast_parameters)
{
- exec_node *actual_ir_node = actual_ir_parameters.head;
- exec_node *actual_ast_node = actual_ast_parameters.head;
+ exec_node *actual_ir_node = actual_ir_parameters.head_sentinel.next;
+ exec_node *actual_ast_node = actual_ast_parameters.head_sentinel.next;
foreach_in_list(const ir_variable, formal, &sig->parameters) {
/* The lists must be the same length. */
@@ -964,7 +964,7 @@ constant_record_constructor(const glsl_type
*constructor_type,
bool
single_scalar_parameter(exec_list *parameters)
{
- const ir_rvalue *const p = (ir_rvalue *) parameters->head;
+ const ir_rvalue *const p = (ir_rvalue *) parameters->head_sentinel.next;
assert(((ir_rvalue *)p)->as_rvalue() != NULL);
return (p->type->is_scalar() && p->next->is_tail_sentinel());
@@ -1008,7 +1008,7 @@ emit_inline_vector_constructor(const glsl_type *type,
*/
const unsigned lhs_components = type->components();
if (single_scalar_parameter(parameters)) {
- ir_rvalue *first_param = (ir_rvalue *)parameters->head;
+ ir_rvalue *first_param = (ir_rvalue *)parameters->head_sentinel.next;
ir_rvalue *rhs = new(ctx) ir_swizzle(first_param, 0, 0, 0, 0,
lhs_components);
ir_dereference_variable *lhs = new(ctx)
ir_dereference_variable(var);
@@ -1209,7 +1209,8 @@ emit_inline_matrix_constructor(const glsl_type *type,
* to the upper left portion of the constructed matrix, and the
remaining
* elements take values from the identity matrix.
*/
- ir_rvalue *const first_param = (ir_rvalue *) parameters->head;
+ ir_rvalue *const first_param =
+ (ir_rvalue *) parameters->head_sentinel.next;
if (single_scalar_parameter(parameters)) {
/* Assign the scalar to the X component of a vec4, and fill the
remaining
* components with zero.
@@ -1454,7 +1455,7 @@ emit_inline_record_constructor(const glsl_type *type,
instructions->push_tail(var);
- exec_node *node = parameters->head;
+ exec_node *node = parameters->head_sentinel.next;
for (unsigned i = 0; i < type->length; i++) {
assert(!node->is_tail_sentinel());
@@ -1487,7 +1488,7 @@ process_record_constructor(exec_list *instructions,
process_parameters(instructions, &actual_parameters,
parameters, state);
- exec_node *node = actual_parameters.head;
+ exec_node *node = actual_parameters.head_sentinel.next;
for (unsigned i = 0; i < constructor_type->length; i++) {
ir_rvalue *ir = (ir_rvalue *) node;
@@ -1751,8 +1752,9 @@ ast_function_expression::hir(exec_list *instructions,
if (all_parameters_are_constant) {
return new(ctx) ir_constant(constructor_type, &actual_parameters);
} else if (constructor_type->is_scalar()) {
- return dereference_component((ir_rvalue *) actual_parameters.head,
- 0);
+ return dereference_component(
+ (ir_rvalue *) actual_parameters.head_sentinel.next,
+ 0);
} else if (constructor_type->is_vector()) {
return emit_inline_vector_constructor(constructor_type,
instructions,
diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index 8cb46be..7452482 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -1761,7 +1761,7 @@ ast_expression::do_hir(exec_list *instructions,
* effect, but I don't think these cases exist in GLSL.
Either way,
* it would be a giant hassle to replicate that behavior.
*/
- if (previous_tail_pred == instructions->tail_pred) {
+ if (previous_tail_pred == instructions->tail_sentinel.prev) {
_mesa_glsl_warning(&previous_operand_loc, state,
"left-hand operand of comma expression
has "
"no effect");
@@ -1772,7 +1772,7 @@ ast_expression::do_hir(exec_list *instructions,
* return NULL when the list is empty. We don't care about that
* here, so using tail_pred directly is fine.
*/
- previous_tail_pred = instructions->tail_pred;
+ previous_tail_pred = instructions->tail_sentinel.prev;
previous_operand_loc = ast->get_location();
result = ast->hir(instructions, state);
@@ -1923,8 +1923,9 @@ process_array_type(YYLTYPE *loc, const glsl_type
*base,
}
}
- for (exec_node *node = array_specifier->array_dimensions.tail_pred;
- !node->is_head_sentinel(); node = node->prev) {
+ for (exec_node *node =
+ array_specifier->array_dimensions.tail_sentinel.prev;
+ !node->is_head_sentinel(); node = node->prev) {
unsigned array_size = process_array_size(node, state);
array_type = glsl_type::get_array_instance(array_type,
array_size);
}
diff --git a/src/glsl/glsl_parser_extras.cpp
b/src/glsl/glsl_parser_extras.cpp
index 046d5d7..91079ec 100644
--- a/src/glsl/glsl_parser_extras.cpp
+++ b/src/glsl/glsl_parser_extras.cpp
@@ -783,7 +783,7 @@ _mesa_ast_set_aggregate_type(const glsl_type *type,
* E.g., if <type> if struct S[2] we want to set each element's
type to
* struct S.
*/
- for (exec_node *expr_node = ai->expressions.head;
+ for (exec_node *expr_node = ai->expressions.head_sentinel.next;
!expr_node->is_tail_sentinel();
expr_node = expr_node->next) {
ast_expression *expr = exec_node_data(ast_expression, expr_node,
@@ -795,7 +795,7 @@ _mesa_ast_set_aggregate_type(const glsl_type *type,
/* If the aggregate is a struct, recursively set its fields' types. */
} else if (type->is_record()) {
- exec_node *expr_node = ai->expressions.head;
+ exec_node *expr_node = ai->expressions.head_sentinel.next;
/* Iterate through the struct's fields. */
for (unsigned i = 0; !expr_node->is_tail_sentinel() && i <
type->length;
@@ -809,7 +809,7 @@ _mesa_ast_set_aggregate_type(const glsl_type *type,
}
/* If the aggregate is a matrix, set its columns' types. */
} else if (type->is_matrix()) {
- for (exec_node *expr_node = ai->expressions.head;
+ for (exec_node *expr_node = ai->expressions.head_sentinel.next;
!expr_node->is_tail_sentinel();
expr_node = expr_node->next) {
ast_expression *expr = exec_node_data(ast_expression, expr_node,
diff --git a/src/glsl/ir.cpp b/src/glsl/ir.cpp
index dbd064f..7b1b396 100644
--- a/src/glsl/ir.cpp
+++ b/src/glsl/ir.cpp
@@ -786,7 +786,7 @@ ir_constant::ir_constant(const struct glsl_type
*type, exec_list *value_list)
this->value.u[i] = 0;
}
- ir_constant *value = (ir_constant *) (value_list->head);
+ ir_constant *value = (ir_constant *) (value_list->head_sentinel.next);
/* Constructors with exactly one scalar argument are special for
vectors
* and matrices. For vectors, the scalar value is replicated to
fill all
@@ -1049,7 +1049,7 @@ ir_constant::get_record_field(const char *name)
if (this->components.is_empty())
return NULL;
- exec_node *node = this->components.head;
+ exec_node *node = this->components.head_sentinel.next;
for (int i = 0; i < idx; i++) {
node = node->next;
@@ -1173,8 +1173,8 @@ ir_constant::has_value(const ir_constant *c) const
}
if (this->type->base_type == GLSL_TYPE_STRUCT) {
- const exec_node *a_node = this->components.head;
- const exec_node *b_node = c->components.head;
+ const exec_node *a_node = this->components.head_sentinel.next;
+ const exec_node *b_node = c->components.head_sentinel.next;
while (!a_node->is_tail_sentinel()) {
assert(!b_node->is_tail_sentinel());
diff --git a/src/glsl/ir_clone.cpp b/src/glsl/ir_clone.cpp
index 914e0e4..c1db237 100644
--- a/src/glsl/ir_clone.cpp
+++ b/src/glsl/ir_clone.cpp
@@ -335,7 +335,7 @@ ir_constant::clone(void *mem_ctx, struct hash_table
*ht) const
ir_constant *c = new(mem_ctx) ir_constant;
c->type = this->type;
- for (exec_node *node = this->components.head
+ for (exec_node *node = this->components.head_sentinel.next
; !node->is_tail_sentinel()
; node = node->next) {
ir_constant *const orig = (ir_constant *) node;
diff --git a/src/glsl/ir_constant_expression.cpp
b/src/glsl/ir_constant_expression.cpp
index 171b8e9..dc0c98c 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -2114,7 +2114,8 @@
ir_function_signature::constant_expression_value(exec_list
*actual_parameters, s
* have to use the variable objects from the object with the body,
* but the parameter instanciation on the current object.
*/
- const exec_node *parameter_info = origin ? origin->parameters.head :
parameters.head;
+ const exec_node *parameter_info = origin ?
+ origin->parameters.head_sentinel.next :
parameters.head_sentinel.next;
foreach_in_list(ir_rvalue, n, actual_parameters) {
ir_constant *constant =
n->constant_expression_value(variable_context);
diff --git a/src/glsl/ir_function.cpp b/src/glsl/ir_function.cpp
index 1319443..8cbd5b0 100644
--- a/src/glsl/ir_function.cpp
+++ b/src/glsl/ir_function.cpp
@@ -43,8 +43,8 @@ static parameter_list_match_t
parameter_lists_match(_mesa_glsl_parse_state *state,
const exec_list *list_a, const exec_list *list_b)
{
- const exec_node *node_a = list_a->head;
- const exec_node *node_b = list_b->head;
+ const exec_node *node_a = list_a->head_sentinel.next;
+ const exec_node *node_b = list_b->head_sentinel.next;
/* This is set to true if there is an inexact match requiring an
implicit
* conversion. */
@@ -221,9 +221,9 @@ is_best_inexact_overload(const exec_list
*actual_parameters,
if (*other == sig)
continue;
- const exec_node *node_a = sig->parameters.head;
- const exec_node *node_b = (*other)->parameters.head;
- const exec_node *node_p = actual_parameters->head;
+ const exec_node *node_a = sig->parameters.head_sentinel.next;
+ const exec_node *node_b = (*other)->parameters.head_sentinel.next;
+ const exec_node *node_p = actual_parameters->head_sentinel.next;
bool better_for_some_parameter = false;
@@ -365,8 +365,8 @@
ir_function::matching_signature(_mesa_glsl_parse_state *state,
static bool
parameter_lists_match_exact(const exec_list *list_a, const exec_list
*list_b)
{
- const exec_node *node_a = list_a->head;
- const exec_node *node_b = list_b->head;
+ const exec_node *node_a = list_a->head_sentinel.next;
+ const exec_node *node_b = list_b->head_sentinel.next;
for (/* empty */
; !node_a->is_tail_sentinel() && !node_b->is_tail_sentinel()
diff --git a/src/glsl/ir_reader.cpp b/src/glsl/ir_reader.cpp
index 4eae413..90c4b29 100644
--- a/src/glsl/ir_reader.cpp
+++ b/src/glsl/ir_reader.cpp
@@ -208,7 +208,8 @@ ir_reader::read_function(s_expression *expr, bool
skip_body)
/* Skip over "function" tag and function name (which are guaranteed
to be
* present by the above PARTIAL_MATCH call).
*/
- exec_node *node = ((s_list *) expr)->subexpressions.head->next->next;
+ exec_node *node =
+ ((s_list *) expr)->subexpressions.head_sentinel.next->next->next;
for (/* nothing */; !node->is_tail_sentinel(); node = node->next) {
s_expression *s_sig = (s_expression *) node;
read_function_sig(f, s_sig, skip_body);
@@ -251,7 +252,7 @@ ir_reader::read_function_sig(ir_function *f,
s_expression *expr, bool skip_body)
state->symbols->push_scope();
/* Skip over the "parameters" tag. */
- exec_node *node = paramlist->subexpressions.head->next;
+ exec_node *node = paramlist->subexpressions.head_sentinel.next->next;
for (/* nothing */; !node->is_tail_sentinel(); node = node->next) {
ir_variable *var = read_declaration((s_expression *) node);
if (var == NULL)
diff --git a/src/glsl/ir_validate.cpp b/src/glsl/ir_validate.cpp
index cfe0df3..f5efcc5 100644
--- a/src/glsl/ir_validate.cpp
+++ b/src/glsl/ir_validate.cpp
@@ -842,8 +842,9 @@ ir_validate::visit_enter(ir_call *ir)
abort();
}
- const exec_node *formal_param_node = callee->parameters.head;
- const exec_node *actual_param_node = ir->actual_parameters.head;
+ const exec_node *formal_param_node =
callee->parameters.head_sentinel.next;
+ const exec_node *actual_param_node =
+ ir->actual_parameters.head_sentinel.next;
while (true) {
if (formal_param_node->is_tail_sentinel()
!= actual_param_node->is_tail_sentinel()) {
diff --git a/src/glsl/list.h b/src/glsl/list.h
index 15fcd4a..ee9145e 100644
--- a/src/glsl/list.h
+++ b/src/glsl/list.h
@@ -32,24 +32,8 @@
*
* A list is empty if either the head sentinel's \c next pointer
points to the
* tail sentinel or the tail sentinel's \c prev poiner points to the head
- * sentinel.
- *
- * Instead of tracking two separate \c node structures and a \c list
structure
- * that points to them, the sentinel nodes are in a single structure.
Noting
- * that each sentinel node always has one \c NULL pointer, the \c NULL
- * pointers occupy the same memory location. In the \c list structure
- * contains a the following:
- *
- * - A \c head pointer that represents the \c next pointer of the
- * head sentinel node.
- * - A \c tail pointer that represents the \c prev pointer of the head
- * sentinel node and the \c next pointer of the tail sentinel
node. This
- * pointer is \b always \c NULL.
- * - A \c tail_prev pointer that represents the \c prev pointer of the
- * tail sentinel node.
- *
- * Therefore, if \c head->next is \c NULL or \c tail_prev->prev is \c NULL,
- * the list is empty.
+ * sentinel. The head sentinel and tail sentinel nodes are allocated within
+ * the list structure.
*
* Do note that this means that the list nodes will contain pointers
into the
* list structure itself and as a result you may not \c realloc() an \c
@@ -307,9 +291,8 @@ struct exec_node;
#endif
struct exec_list {
- struct exec_node *head;
- struct exec_node *tail;
- struct exec_node *tail_pred;
+ struct exec_node head_sentinel;
+ struct exec_node tail_sentinel;
#ifdef __cplusplus
DECLARE_RALLOC_CXX_OPERATORS(exec_list)
@@ -366,9 +349,10 @@ struct exec_list {
static inline void
exec_list_make_empty(struct exec_list *list)
{
- list->head = (struct exec_node *) & list->tail;
- list->tail = NULL;
- list->tail_pred = (struct exec_node *) & list->head;
+ list->head_sentinel.next = & list->tail_sentinel;
+ list->head_sentinel.prev = NULL;
+ list->tail_sentinel.next = NULL;
+ list->tail_sentinel.prev = & list->head_sentinel;
}
static inline bool
@@ -376,39 +360,39 @@ exec_list_is_empty(const struct exec_list *list)
{
/* There are three ways to test whether a list is empty or not.
*
- * - Check to see if the \c head points to the \c tail.
- * - Check to see if the \c tail_pred points to the \c head.
- * - Check to see if the \c head is the sentinel node by test
whether its
+ * - Check to see if the head sentinel's \c next is the tail sentinel.
+ * - Check to see if the tail sentinel's \c prev is the head sentinel.
+ * - Check to see if the head is the sentinel node by test whether its
* \c next pointer is \c NULL.
*
* The first two methods tend to generate better code on modern systems
* because they save a pointer dereference.
*/
- return list->head == (struct exec_node *) &list->tail;
+ return list->head_sentinel.next == & list->tail_sentinel;
}
static inline const struct exec_node *
exec_list_get_head_const(const struct exec_list *list)
{
- return !exec_list_is_empty(list) ? list->head : NULL;
+ return !exec_list_is_empty(list) ? list->head_sentinel.next : NULL;
}
static inline struct exec_node *
exec_list_get_head(struct exec_list *list)
{
- return !exec_list_is_empty(list) ? list->head : NULL;
+ return !exec_list_is_empty(list) ? list->head_sentinel.next : NULL;
}
static inline const struct exec_node *
exec_list_get_tail_const(const struct exec_list *list)
{
- return !exec_list_is_empty(list) ? list->tail_pred : NULL;
+ return !exec_list_is_empty(list) ? list->tail_sentinel.prev : NULL;
}
static inline struct exec_node *
exec_list_get_tail(struct exec_list *list)
{
- return !exec_list_is_empty(list) ? list->tail_pred : NULL;
+ return !exec_list_is_empty(list) ? list->tail_sentinel.prev : NULL;
}
static inline unsigned
@@ -417,7 +401,8 @@ exec_list_length(const struct exec_list *list)
unsigned size = 0;
struct exec_node *node;
- for (node = list->head; node->next != NULL; node = node->next) {
+ for (node = list->head_sentinel.next; node->next != NULL;
+ node = node->next) {
size++;
}
@@ -427,21 +412,21 @@ exec_list_length(const struct exec_list *list)
static inline void
exec_list_push_head(struct exec_list *list, struct exec_node *n)
{
- n->next = list->head;
- n->prev = (struct exec_node *) &list->head;
+ n->next = list->head_sentinel.next;
+ n->prev = &list->head_sentinel;
n->next->prev = n;
- list->head = n;
+ list->head_sentinel.next = n;
}
static inline void
exec_list_push_tail(struct exec_list *list, struct exec_node *n)
{
- n->next = (struct exec_node *) &list->tail;
- n->prev = list->tail_pred;
+ n->next = &list->tail_sentinel;
+ n->prev = list->tail_sentinel.prev;
n->prev->next = n;
- list->tail_pred = n;
+ list->tail_sentinel.prev = n;
}
static inline void
@@ -449,10 +434,10 @@ exec_list_push_degenerate_list_at_head(struct
exec_list *list, struct exec_node
{
assert(n->prev->next == n);
- n->prev->next = list->head;
- list->head->prev = n->prev;
- n->prev = (struct exec_node *) &list->head;
- list->head = n;
+ n->prev->next = list->head_sentinel.next;
+ list->head_sentinel.next->prev = n->prev;
+ n->prev = &list->head_sentinel;
+ list->head_sentinel.next = n;
}
static inline struct exec_node *
@@ -471,12 +456,13 @@ exec_list_move_nodes_to(struct exec_list *list,
struct exec_list *target)
if (exec_list_is_empty(list)) {
exec_list_make_empty(target);
} else {
- target->head = list->head;
- target->tail = NULL;
- target->tail_pred = list->tail_pred;
+ target->head_sentinel.next = list->head_sentinel.next;
+ target->head_sentinel.prev = NULL;
+ target->tail_sentinel.next = NULL;
+ target->tail_sentinel.prev = list->tail_sentinel.prev;
- target->head->prev = (struct exec_node *) &target->head;
- target->tail_pred->next = (struct exec_node *) &target->tail;
+ target->head_sentinel.next->prev = &target->head_sentinel;
+ target->tail_sentinel.prev->next = &target->tail_sentinel;
exec_list_make_empty(list);
}
@@ -490,13 +476,13 @@ exec_list_append(struct exec_list *list, struct
exec_list *source)
/* Link the first node of the source with the last node of the
target list.
*/
- list->tail_pred->next = source->head;
- source->head->prev = list->tail_pred;
+ list->tail_sentinel.prev->next = source->head_sentinel.next;
+ source->head_sentinel.next->prev = list->tail_sentinel.prev;
/* Make the tail of the source list be the tail of the target list.
*/
- list->tail_pred = source->tail_pred;
- list->tail_pred->next = (struct exec_node *) &list->tail;
+ list->tail_sentinel.prev = source->tail_sentinel.prev;
+ list->tail_sentinel.prev->next = &list->tail_sentinel;
/* Make the source list empty for good measure.
*/
@@ -516,11 +502,11 @@ exec_node_insert_list_before(struct exec_node *n,
struct exec_list *before)
if (exec_list_is_empty(before))
return;
- before->tail_pred->next = n;
- before->head->prev = n->prev;
+ before->tail_sentinel.prev->next = n;
+ before->head_sentinel.next->prev = n->prev;
- n->prev->next = before->head;
- n->prev = before->tail_pred;
+ n->prev->next = before->head_sentinel.next;
+ n->prev = before->tail_sentinel.prev;
exec_list_make_empty(before);
}
@@ -530,15 +516,17 @@ exec_list_validate(const struct exec_list *list)
{
const struct exec_node *node;
- assert(list->head->prev == (const struct exec_node *) &list->head);
- assert(list->tail == NULL);
- assert(list->tail_pred->next == (const struct exec_node *) &list->tail);
+ assert(list->head_sentinel.next->prev == &list->head_sentinel);
+ assert(list->head_sentinel.prev == NULL);
+ assert(list->tail_sentinel.next == NULL);
+ assert(list->tail_sentinel.prev->next == &list->tail_sentinel);
/* We could try to use one of the interators below for this but
they all
* either require C++ or assume the exec_node is embedded in a
structure
* which is not the case for this function.
*/
- for (node = list->head; node->next != NULL; node = node->next) {
+ for (node = list->head_sentinel.next; node->next != NULL;
+ node = node->next) {
assert(node->next->prev == node);
assert(node->prev->next == node);
}
@@ -622,12 +610,12 @@ inline void exec_node::insert_before(exec_list
*before)
#endif
#define foreach_in_list(__type, __inst, __list) \
- for (__type *(__inst) = (__type *)(__list)->head; \
+ for (__type *(__inst) = (__type *)(__list)->head_sentinel.next; \
!(__inst)->is_tail_sentinel(); \
(__inst) = (__type *)(__inst)->next)
#define foreach_in_list_reverse(__type, __inst, __list) \
- for (__type *(__inst) = (__type *)(__list)->tail_pred; \
+ for (__type *(__inst) = (__type *)(__list)->tail_sentinel.prev; \
!(__inst)->is_head_sentinel(); \
(__inst) = (__type *)(__inst)->prev)
@@ -635,20 +623,20 @@ inline void exec_node::insert_before(exec_list
*before)
* This version is safe even if the current node is removed.
*/
#define foreach_in_list_safe(__type, __node, __list) \
- for (__type *__node = (__type *)(__list)->head, \
+ for (__type *__node = (__type *)(__list)->head_sentinel.next, \
*__next = (__type *)__node->next; \
__next != NULL; \
__node = __next, __next = (__type *)__next->next)
#define foreach_in_list_reverse_safe(__type, __node, __list) \
- for (__type *__node = (__type *)(__list)->tail_pred, \
+ for (__type *__node = (__type *)(__list)->tail_sentinel.prev, \
*__prev = (__type *)__node->prev; \
__prev != NULL; \
__node = __prev, __prev = (__type *)__prev->prev)
#define foreach_in_list_use_after(__type, __inst, __list) \
__type *(__inst); \
- for ((__inst) = (__type *)(__list)->head; \
+ for ((__inst) = (__type *)(__list)->head_sentinel.next; \
!(__inst)->is_tail_sentinel(); \
(__inst) = (__type *)(__inst)->next)
/**
@@ -657,8 +645,8 @@ inline void exec_node::insert_before(exec_list *before)
* This is safe against either current node being removed or replaced.
*/
#define foreach_two_lists(__node1, __list1, __node2, __list2) \
- for (struct exec_node * __node1 = (__list1)->head, \
- * __node2 = (__list2)->head, \
+ for (struct exec_node * __node1 = (__list1)->head_sentinel.next, \
+ * __node2 = (__list2)->head_sentinel.next, \
* __next1 = __node1->next, \
* __next2 = __node2->next \
; __next1 != NULL && __next2 != NULL \
@@ -669,19 +657,19 @@ inline void exec_node::insert_before(exec_list
*before)
#define foreach_list_typed(__type, __node, __field, __list) \
for (__type * __node = \
- exec_node_data(__type, (__list)->head, __field); \
+ exec_node_data(__type, (__list)->head_sentinel.next, __field); \
(__node)->__field.next != NULL; \
(__node) = exec_node_data(__type, (__node)->__field.next, __field))
#define foreach_list_typed_reverse(__type, __node, __field,
__list) \
for (__type * __node = \
- exec_node_data(__type, (__list)->tail_pred, __field); \
+ exec_node_data(__type, (__list)->tail_sentinel.prev,
__field); \
(__node)->__field.prev != NULL; \
(__node) = exec_node_data(__type, (__node)->__field.prev,
__field))
#define foreach_list_typed_safe(__type, __node, __field,
__list) \
for (__type * __node
= \
- exec_node_data(__type, (__list)->head,
__field), \
+ exec_node_data(__type, (__list)->head_sentinel.next,
__field), \
* __next
= \
exec_node_data(__type, (__node)->__field.next,
__field); \
(__node)->__field.next !=
NULL; \
@@ -690,7 +678,7 @@ inline void exec_node::insert_before(exec_list *before)
#define foreach_list_typed_safe_reverse(__type, __node, __field,
__list) \
for (__type * __node
= \
- exec_node_data(__type, (__list)->tail_pred,
__field), \
+ exec_node_data(__type, (__list)->tail_sentinel.prev,
__field), \
* __prev
= \
exec_node_data(__type, (__node)->__field.prev,
__field); \
(__node)->__field.prev !=
NULL; \
diff --git a/src/glsl/lower_clip_distance.cpp
b/src/glsl/lower_clip_distance.cpp
index 01f028b..f8e130b 100644
--- a/src/glsl/lower_clip_distance.cpp
+++ b/src/glsl/lower_clip_distance.cpp
@@ -476,8 +476,10 @@ lower_clip_distance_visitor::visit_leave(ir_call *ir)
{
void *ctx = ralloc_parent(ir);
- const exec_node *formal_param_node = ir->callee->parameters.head;
- const exec_node *actual_param_node = ir->actual_parameters.head;
+ const exec_node *formal_param_node =
+ ir->callee->parameters.head_sentinel.next;
+ const exec_node *actual_param_node =
+ ir->actual_parameters.head_sentinel.next;
while (!actual_param_node->is_tail_sentinel()) {
ir_variable *formal_param = (ir_variable *) formal_param_node;
ir_rvalue *actual_param = (ir_rvalue *) actual_param_node;
diff --git a/src/glsl/lower_jumps.cpp b/src/glsl/lower_jumps.cpp
index ec7a0c5..cdc362e 100644
--- a/src/glsl/lower_jumps.cpp
+++ b/src/glsl/lower_jumps.cpp
@@ -777,7 +777,7 @@ lower_continue:
* analysis.
*/
exec_list list;
- list.head = next;
+ list.head_sentinel.next = next;
block_records[move_into] = visit_block(&list);
/*
diff --git a/src/glsl/lower_packed_varyings.cpp
b/src/glsl/lower_packed_varyings.cpp
index d8bebb5..32118e5 100644
--- a/src/glsl/lower_packed_varyings.cpp
+++ b/src/glsl/lower_packed_varyings.cpp
@@ -719,7 +719,8 @@ lower_packed_varyings(void *mem_ctx, unsigned
locations_used,
lower_packed_varyings_gs_splicer splicer(mem_ctx,
&new_instructions);
/* Add all the variables in first. */
- main_func_sig->body.head->insert_before(&new_variables);
+ main_func_sig->body.head_sentinel.next->
+ insert_before(&new_variables);
/* Now update all the EmitVertex instances */
splicer.run(instructions);
@@ -732,7 +733,8 @@ lower_packed_varyings(void *mem_ctx, unsigned
locations_used,
}
} else {
/* Shader inputs need to be lowered at the beginning of main() */
- main_func_sig->body.head->insert_before(&new_instructions);
- main_func_sig->body.head->insert_before(&new_variables);
+ main_func_sig->body.head_sentinel.next->
+ insert_before(&new_instructions);
+ main_func_sig->body.head_sentinel.next->insert_before(&new_variables);
}
}
diff --git a/src/glsl/nir/nir.c b/src/glsl/nir/nir.c
index f03e80a..5338b68 100644
--- a/src/glsl/nir/nir.c
+++ b/src/glsl/nir/nir.c
@@ -1169,14 +1169,16 @@ nir_cf_node_insert_before(nir_cf_node *node,
nir_cf_node *before)
void
nir_cf_node_insert_begin(struct exec_list *list, nir_cf_node *node)
{
- nir_cf_node *begin = exec_node_data(nir_cf_node, list->head, node);
+ nir_cf_node *begin = exec_node_data(nir_cf_node,
+ list->head_sentinel.next, node);
nir_cf_node_insert_before(begin, node);
}
void
nir_cf_node_insert_end(struct exec_list *list, nir_cf_node *node)
{
- nir_cf_node *end = exec_node_data(nir_cf_node, list->tail_pred, node);
+ nir_cf_node *end = exec_node_data(nir_cf_node,
+ list->tail_sentinel.prev, node);
nir_cf_node_insert_after(end, node);
}
diff --git a/src/glsl/nir/nir_opt_gcm.c b/src/glsl/nir/nir_opt_gcm.c
index 44068bf..f091118 100644
--- a/src/glsl/nir/nir_opt_gcm.c
+++ b/src/glsl/nir/nir_opt_gcm.c
@@ -477,7 +477,7 @@ opt_gcm_impl(nir_function_impl *impl)
while (!exec_list_is_empty(&state.instrs)) {
nir_instr *instr = exec_node_data(nir_instr,
- state.instrs.tail_pred, node);
+ state.instrs.tail_sentinel.prev, node);
gcm_place_instr(instr, &state);
}
diff --git a/src/glsl/opt_conditional_discard.cpp
b/src/glsl/opt_conditional_discard.cpp
index 8a3ad24..033033b 100644
--- a/src/glsl/opt_conditional_discard.cpp
+++ b/src/glsl/opt_conditional_discard.cpp
@@ -65,13 +65,15 @@ opt_conditional_discard_visitor::visit_leave(ir_if *ir)
{
/* Look for "if (...) discard" with no else clause or extra
statements. */
if (ir->then_instructions.is_empty() ||
- !ir->then_instructions.head->next->is_tail_sentinel() ||
- !((ir_instruction *) ir->then_instructions.head)->as_discard() ||
+ !ir->then_instructions.head_sentinel.next->next->is_tail_sentinel() ||
+ !((ir_instruction *) ir->then_instructions.head_sentinel.next)->
+ as_discard() ||
!ir->else_instructions.is_empty())
return visit_continue;
/* Move the condition and replace the ir_if with the ir_discard. */
- ir_discard *discard = (ir_discard *) ir->then_instructions.head;
+ ir_discard *discard =
+ (ir_discard *) ir->then_instructions.head_sentinel.next;
discard->condition = ir->condition;
ir->replace_with(discard);
diff --git a/src/glsl/opt_constant_variable.cpp
b/src/glsl/opt_constant_variable.cpp
index 7222eb9..79f27e8 100644
--- a/src/glsl/opt_constant_variable.cpp
+++ b/src/glsl/opt_constant_variable.cpp
@@ -175,7 +175,8 @@ do_constant_variable(exec_list *instructions)
while (!v.list.is_empty()) {
struct assignment_entry *entry;
- entry = exec_node_data(struct assignment_entry, v.list.head, link);
+ entry = exec_node_data(struct assignment_entry,
+ v.list.head_sentinel.next, link);
if (entry->assignment_count == 1 && entry->constval &&
entry->our_scope) {
entry->var->constant_value = entry->constval;
diff --git a/src/glsl/opt_dead_builtin_varyings.cpp
b/src/glsl/opt_dead_builtin_varyings.cpp
index 31719d2..b4a2a90 100644
--- a/src/glsl/opt_dead_builtin_varyings.cpp
+++ b/src/glsl/opt_dead_builtin_varyings.cpp
@@ -373,7 +373,7 @@ public:
new_var[i]->data.explicit_index = 0;
}
- ir->head->insert_before(new_var[i]);
+ ir->head_sentinel.next->insert_before(new_var[i]);
}
}
}
diff --git a/src/glsl/opt_flatten_nested_if_blocks.cpp
b/src/glsl/opt_flatten_nested_if_blocks.cpp
index c702102..de87dfc 100644
--- a/src/glsl/opt_flatten_nested_if_blocks.cpp
+++ b/src/glsl/opt_flatten_nested_if_blocks.cpp
@@ -90,7 +90,8 @@ nested_if_flattener::visit_leave(ir_if *ir)
if (ir->then_instructions.is_empty() ||
!ir->else_instructions.is_empty())
return visit_continue;
- ir_if *inner = ((ir_instruction *) ir->then_instructions.head)->as_if();
+ ir_if *inner =
+ ((ir_instruction *)
ir->then_instructions.head_sentinel.next)->as_if();
if (!inner || !inner->next->is_tail_sentinel() ||
!inner->else_instructions.is_empty())
return visit_continue;
diff --git a/src/mesa/drivers/dri/i965/brw_cfg.h
b/src/mesa/drivers/dri/i965/brw_cfg.h
index a094917..a632c5f 100644
--- a/src/mesa/drivers/dri/i965/brw_cfg.h
+++ b/src/mesa/drivers/dri/i965/brw_cfg.h
@@ -313,12 +313,12 @@ struct cfg_t {
#define foreach_inst_in_block(__type, __inst, __block) \
foreach_in_list(__type, __inst, &(__block)->instructions)
-#define foreach_inst_in_block_safe(__type, __inst, __block) \
- for (__type *__inst = (__type *)__block->instructions.head, \
- *__next = (__type *)__inst->next, \
- *__end = (__type *)__block->instructions.tail; \
- __next != __end; \
- __inst = __next, \
+#define foreach_inst_in_block_safe(__type, __inst,
__block) \
+ for (__type *__inst = (__type
*)__block->instructions.head_sentinel.next, \
+ *__next = (__type
*)__inst->next, \
+ *__end = (__type
*)__block->instructions.tail_sentinel.next; \
+ __next !=
__end; \
+ __inst =
__next, \
__next = (__type *)__next->next)
#define foreach_inst_in_block_reverse(__type, __inst, __block) \
diff --git a/src/mesa/drivers/dri/i965/brw_fs_builder.h
b/src/mesa/drivers/dri/i965/brw_fs_builder.h
index 58ac598..9f08ea5 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_builder.h
+++ b/src/mesa/drivers/dri/i965/brw_fs_builder.h
@@ -85,7 +85,7 @@ namespace brw {
fs_builder
at_end() const
{
- return at(NULL, (exec_node *)&shader->instructions.tail);
+ return at(NULL, &shader->instructions.tail_sentinel);
}
/**
--
2.4.4
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