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25 * \file ir_array_refcount.cpp
27 * Provides a visitor which produces a list of variables referenced.
31 #include "ir_visitor.h"
32 #include "ir_array_refcount.h"
33 #include "compiler/glsl_types.h"
34 #include "util/hash_table.h"
36 ir_array_refcount_visitor::ir_array_refcount_visitor()
37 : derefs(0), num_derefs(0), derefs_size(0)
39 this->mem_ctx
= ralloc_context(NULL
);
40 this->ht
= _mesa_hash_table_create(NULL
, _mesa_hash_pointer
,
41 _mesa_key_pointer_equal
);
45 free_entry(struct hash_entry
*entry
)
47 ir_array_refcount_entry
*ivre
= (ir_array_refcount_entry
*) entry
->data
;
51 ir_array_refcount_visitor::~ir_array_refcount_visitor()
53 ralloc_free(this->mem_ctx
);
54 _mesa_hash_table_destroy(this->ht
, free_entry
);
57 ir_array_refcount_entry::ir_array_refcount_entry(ir_variable
*var
)
58 : var(var
), is_referenced(false)
60 num_bits
= MAX2(1, var
->type
->arrays_of_arrays_size());
61 bits
= new BITSET_WORD
[BITSET_WORDS(num_bits
)];
62 memset(bits
, 0, BITSET_WORDS(num_bits
) * sizeof(bits
[0]));
64 /* Count the "depth" of the arrays-of-arrays. */
66 for (const glsl_type
*type
= var
->type
;
68 type
= type
->fields
.array
) {
74 ir_array_refcount_entry::~ir_array_refcount_entry()
81 ir_array_refcount_entry::mark_array_elements_referenced(const array_deref_range
*dr
,
84 if (count
!= array_depth
)
87 mark_array_elements_referenced(dr
, count
, 1, 0);
91 ir_array_refcount_entry::mark_array_elements_referenced(const array_deref_range
*dr
,
94 unsigned linearized_index
)
96 /* Walk through the list of array dereferences in least- to
97 * most-significant order. Along the way, accumulate the current
98 * linearized offset and the scale factor for each array-of-.
100 for (unsigned i
= 0; i
< count
; i
++) {
101 if (dr
[i
].index
< dr
[i
].size
) {
102 linearized_index
+= dr
[i
].index
* scale
;
105 /* For each element in the current array, update the count and
106 * offset, then recurse to process the remaining arrays.
108 * There is some inefficency here if the last element in the
109 * array_deref_range list specifies the entire array. In that case,
110 * the loop will make recursive calls with count == 0. In the call,
111 * all that will happen is the bit will be set.
113 for (unsigned j
= 0; j
< dr
[i
].size
; j
++) {
114 mark_array_elements_referenced(&dr
[i
+ 1],
117 linearized_index
+ (j
* scale
));
124 BITSET_SET(bits
, linearized_index
);
127 ir_array_refcount_entry
*
128 ir_array_refcount_visitor::get_variable_entry(ir_variable
*var
)
132 struct hash_entry
*e
= _mesa_hash_table_search(this->ht
, var
);
134 return (ir_array_refcount_entry
*)e
->data
;
136 ir_array_refcount_entry
*entry
= new ir_array_refcount_entry(var
);
137 _mesa_hash_table_insert(this->ht
, var
, entry
);
144 ir_array_refcount_visitor::get_array_deref()
146 if ((num_derefs
+ 1) * sizeof(array_deref_range
) > derefs_size
) {
147 void *ptr
= reralloc_size(mem_ctx
, derefs
, derefs_size
+ 4096);
153 derefs
= (array_deref_range
*)ptr
;
156 array_deref_range
*d
= &derefs
[num_derefs
];
164 ir_array_refcount_visitor::visit(ir_dereference_variable
*ir
)
166 ir_variable
*const var
= ir
->variable_referenced();
167 ir_array_refcount_entry
*entry
= this->get_variable_entry(var
);
169 entry
->is_referenced
= true;
171 return visit_continue
;
176 ir_array_refcount_visitor::visit_enter(ir_function_signature
*ir
)
178 /* We don't want to descend into the function parameters and
179 * dead-code eliminate them, so just accept the body here.
181 visit_list_elements(this, &ir
->body
);
182 return visit_continue_with_parent
;