src/compiler/nir/nir_inline_functions.c

   1 /*
   2  * Copyright © 2015 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 DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include "nir.h"
  25 #include "nir_builder.h"
  26 #include "nir_control_flow.h"
  27
  28 struct inline_functions_state {
  29    struct set *inlined;
  30    nir_builder builder;
  31    bool progress;
  32 };
  33
  34 static bool inline_function_impl(nir_function_impl *impl, struct set *inlined);
  35
  36 static bool
  37 inline_functions_block(nir_block *block, void *void_state)
  38 {
  39    struct inline_functions_state *state = void_state;
  40
  41    nir_builder *b = &state->builder;
  42
  43    /* This is tricky.  We're iterating over instructions in a block but, as
  44     * we go, the block and its instruction list are being split into
  45     * pieces.  However, this *should* be safe since foreach_safe always
  46     * stashes the next thing in the iteration.  That next thing will
  47     * properly get moved to the next block when it gets split, and we
  48     * continue iterating there.
  49     */
  50    nir_foreach_instr_safe(block, instr) {
  51       if (instr->type != nir_instr_type_call)
  52          continue;
  53
  54       state->progress = true;
  55
  56       nir_call_instr *call = nir_instr_as_call(instr);
  57       assert(call->callee->impl);
  58
  59       inline_function_impl(call->callee->impl, state->inlined);
  60
  61       nir_function_impl *callee_copy =
  62          nir_function_impl_clone(call->callee->impl);
  63
  64       exec_list_append(&b->impl->locals, &callee_copy->locals);
  65       exec_list_append(&b->impl->registers, &callee_copy->registers);
  66
  67       b->cursor = nir_before_instr(&call->instr);
  68
  69       /* Add copies of all in parameters */
  70       assert(call->num_params == callee_copy->num_params);
  71       for (unsigned i = 0; i < callee_copy->num_params; i++) {
  72          /* Only in or inout parameters */
  73          if (call->callee->params[i].param_type == nir_parameter_out)
  74             continue;
  75
  76          nir_copy_deref_var(b, nir_deref_var_create(b->shader,
  77                                                     callee_copy->params[i]),
  78                                call->params[i]);
  79       }
  80
  81       /* Pluck the body out of the function and place it here */
  82       nir_cf_list body;
  83       nir_cf_list_extract(&body, &callee_copy->body);
  84       nir_cf_reinsert(&body, b->cursor);
  85
  86       b->cursor = nir_before_instr(&call->instr);
  87
  88       /* Add copies of all out parameters and the return */
  89       assert(call->num_params == callee_copy->num_params);
  90       for (unsigned i = 0; i < callee_copy->num_params; i++) {
  91          /* Only out or inout parameters */
  92          if (call->callee->params[i].param_type == nir_parameter_in)
  93             continue;
  94
  95          nir_copy_deref_var(b, call->params[i],
  96                                nir_deref_var_create(b->shader,
  97                                                     callee_copy->params[i]));
  98       }
  99       if (!glsl_type_is_void(call->callee->return_type)) {
 100          nir_copy_deref_var(b, call->return_deref,
 101                                nir_deref_var_create(b->shader,
 102                                                     callee_copy->return_var));
 103       }
 104
 105       nir_instr_remove(&call->instr);
 106    }
 107
 108    return true;
 109 }
 110
 111 static bool
 112 inline_function_impl(nir_function_impl *impl, struct set *inlined)
 113 {
 114    if (_mesa_set_search(inlined, impl))
 115       return false; /* Already inlined */
 116
 117    struct inline_functions_state state;
 118
 119    state.inlined = inlined;
 120    state.progress = false;
 121    nir_builder_init(&state.builder, impl);
 122
 123    nir_foreach_block(impl, inline_functions_block, &state);
 124
 125    if (state.progress) {
 126       /* SSA and register indices are completely messed up now */
 127       nir_index_ssa_defs(impl);
 128       nir_index_local_regs(impl);
 129
 130       nir_metadata_preserve(impl, nir_metadata_none);
 131    }
 132
 133    _mesa_set_add(inlined, impl);
 134
 135    return state.progress;
 136 }
 137
 138 bool
 139 nir_inline_functions(nir_shader *shader)
 140 {
 141    struct set *inlined = _mesa_set_create(NULL, _mesa_hash_pointer,
 142                                           _mesa_key_pointer_equal);
 143    bool progress = false;
 144
 145    nir_foreach_function(shader, function) {
 146       if (function->impl)
 147          progress = inline_function_impl(function->impl, inlined) || progress;
 148    }
 149
 150    _mesa_set_destroy(inlined, NULL);
 151
 152    return progress;
 153 }