src/glsl/ir_function_inlining.cpp

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * \file ir_function_inlining.cpp
  26  *
  27  * Replaces calls to functions with the body of the function.
  28  */
  29
  30 #include <inttypes.h>
  31 #include "ir.h"
  32 #include "ir_visitor.h"
  33 #include "ir_function_inlining.h"
  34 #include "ir_expression_flattening.h"
  35 #include "glsl_types.h"
  36 extern "C" {
  37 #include "hash_table.h"
  38 }
  39
  40 class ir_function_inlining_visitor : public ir_hierarchical_visitor {
  41 public:
  42    ir_function_inlining_visitor()
  43    {
  44       progress = false;
  45    }
  46
  47    virtual ~ir_function_inlining_visitor()
  48    {
  49       /* empty */
  50    }
  51
  52    virtual ir_visitor_status visit_enter(ir_expression *);
  53    virtual ir_visitor_status visit_enter(ir_call *);
  54    virtual ir_visitor_status visit_enter(ir_assignment *);
  55    virtual ir_visitor_status visit_enter(ir_return *);
  56    virtual ir_visitor_status visit_enter(ir_texture *);
  57    virtual ir_visitor_status visit_enter(ir_swizzle *);
  58
  59    bool progress;
  60 };
  61
  62
  63 unsigned int hash_func(const void *key)
  64 {
  65    return (unsigned int)(uintptr_t)key;
  66 }
  67
  68 int hash_compare_func(const void *key1, const void *key2)
  69 {
  70    return key1 == key2 ? 0 : 1;
  71 }
  72
  73 bool
  74 automatic_inlining_predicate(ir_instruction *ir)
  75 {
  76    ir_call *call = ir->as_call();
  77
  78    if (call && can_inline(call))
  79       return true;
  80
  81    return false;
  82 }
  83
  84 bool
  85 do_function_inlining(exec_list *instructions)
  86 {
  87    ir_function_inlining_visitor v;
  88
  89    do_expression_flattening(instructions, automatic_inlining_predicate);
  90
  91    v.run(instructions);
  92
  93    return v.progress;
  94 }
  95
  96 static void
  97 replace_return_with_assignment(ir_instruction *ir, void *data)
  98 {
  99    void *ctx = talloc_parent(ir);
 100    ir_variable *retval = (ir_variable *)data;
 101    ir_return *ret = ir->as_return();
 102
 103    if (ret) {
 104       if (ret->value) {
 105          ir_rvalue *lhs = new(ctx) ir_dereference_variable(retval);
 106          ret->insert_before(new(ctx) ir_assignment(lhs, ret->value, NULL));
 107          ret->remove();
 108       } else {
 109          /* un-valued return has to be the last return, or we shouldn't
 110           * have reached here. (see can_inline()).
 111           */
 112          assert(!ret->next->is_tail_sentinal());
 113       }
 114    }
 115 }
 116
 117 ir_rvalue *
 118 ir_call::generate_inline(ir_instruction *next_ir)
 119 {
 120    void *ctx = talloc_parent(this);
 121    ir_variable **parameters;
 122    int num_parameters;
 123    int i;
 124    ir_variable *retval = NULL;
 125    struct hash_table *ht;
 126
 127    ht = hash_table_ctor(0, hash_func, hash_compare_func);
 128
 129    num_parameters = 0;
 130    foreach_iter(exec_list_iterator, iter_sig, this->callee->parameters)
 131       num_parameters++;
 132
 133    parameters = new ir_variable *[num_parameters];
 134
 135    /* Generate storage for the return value. */
 136    if (this->callee->return_type) {
 137       retval = new(ctx) ir_variable(this->callee->return_type, "__retval");
 138       next_ir->insert_before(retval);
 139    }
 140
 141    /* Generate the declarations for the parameters to our inlined code,
 142     * and set up the mapping of real function body variables to ours.
 143     */
 144    i = 0;
 145    exec_list_iterator sig_param_iter = this->callee->parameters.iterator();
 146    exec_list_iterator param_iter = this->actual_parameters.iterator();
 147    for (i = 0; i < num_parameters; i++) {
 148       const ir_variable *const sig_param = (ir_variable *) sig_param_iter.get();
 149       ir_rvalue *param = (ir_rvalue *) param_iter.get();
 150
 151       /* Generate a new variable for the parameter. */
 152       parameters[i] = (ir_variable *)sig_param->clone(ht);
 153       parameters[i]->mode = ir_var_auto;
 154       next_ir->insert_before(parameters[i]);
 155
 156       /* Move the actual param into our param variable if it's an 'in' type. */
 157       if (sig_param->mode == ir_var_in ||
 158           sig_param->mode == ir_var_inout) {
 159          ir_assignment *assign;
 160
 161          assign = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(parameters[i]),
 162                                          param, NULL);
 163          next_ir->insert_before(assign);
 164       }
 165
 166       sig_param_iter.next();
 167       param_iter.next();
 168    }
 169
 170    /* Generate the inlined body of the function. */
 171    foreach_iter(exec_list_iterator, iter, callee->body) {
 172       ir_instruction *ir = (ir_instruction *)iter.get();
 173       ir_instruction *new_ir = ir->clone(ht);
 174
 175       next_ir->insert_before(new_ir);
 176       visit_tree(new_ir, replace_return_with_assignment, retval);
 177    }
 178
 179    /* Copy back the value of any 'out' parameters from the function body
 180     * variables to our own.
 181     */
 182    i = 0;
 183    param_iter = this->actual_parameters.iterator();
 184    for (i = 0; i < num_parameters; i++) {
 185       ir_instruction *const param = (ir_instruction *) param_iter.get();
 186
 187       /* Move our param variable into the actual param if it's an 'out' type. */
 188       if (parameters[i]->mode == ir_var_out ||
 189           parameters[i]->mode == ir_var_inout) {
 190          ir_assignment *assign;
 191
 192          assign = new(ctx) ir_assignment(param->as_rvalue(),
 193                                          new(ctx) ir_dereference_variable(parameters[i]),
 194                                          NULL);
 195          next_ir->insert_before(assign);
 196       }
 197
 198       param_iter.next();
 199    }
 200
 201    delete [] parameters;
 202
 203    hash_table_dtor(ht);
 204
 205    if (retval)
 206       return new(ctx) ir_dereference_variable(retval);
 207    else
 208       return NULL;
 209 }
 210
 211
 212 ir_visitor_status
 213 ir_function_inlining_visitor::visit_enter(ir_expression *ir)
 214 {
 215    (void) ir;
 216    return visit_continue_with_parent;
 217 }
 218
 219
 220 ir_visitor_status
 221 ir_function_inlining_visitor::visit_enter(ir_return *ir)
 222 {
 223    (void) ir;
 224    return visit_continue_with_parent;
 225 }
 226
 227
 228 ir_visitor_status
 229 ir_function_inlining_visitor::visit_enter(ir_texture *ir)
 230 {
 231    (void) ir;
 232    return visit_continue_with_parent;
 233 }
 234
 235
 236 ir_visitor_status
 237 ir_function_inlining_visitor::visit_enter(ir_swizzle *ir)
 238 {
 239    (void) ir;
 240    return visit_continue_with_parent;
 241 }
 242
 243
 244 ir_visitor_status
 245 ir_function_inlining_visitor::visit_enter(ir_call *ir)
 246 {
 247    if (can_inline(ir)) {
 248       (void) ir->generate_inline(ir);
 249       ir->remove();
 250       this->progress = true;
 251    }
 252
 253    return visit_continue;
 254 }
 255
 256
 257 ir_visitor_status
 258 ir_function_inlining_visitor::visit_enter(ir_assignment *ir)
 259 {
 260    ir_call *call = ir->rhs->as_call();
 261    if (!call || !can_inline(call))
 262       return visit_continue;
 263
 264    /* generates the parameter setup, function body, and returns the return
 265     * value of the function
 266     */
 267    ir_rvalue *rhs = call->generate_inline(ir);
 268    assert(rhs);
 269
 270    ir->rhs = rhs;
 271    this->progress = true;
 272
 273    return visit_continue;
 274 }