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