src/util/register_allocate.h

   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 DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *
  26  */
  27
  28 #ifndef REGISTER_ALLOCATE_H
  29 #define REGISTER_ALLOCATE_H
  30
  31 #include <stdbool.h>
  32 #include "util/bitset.h"
  33
  34 #ifdef __cplusplus
  35 extern "C" {
  36 #endif
  37
  38
  39 struct ra_class;
  40 struct ra_regs;
  41
  42 struct blob;
  43 struct blob_reader;
  44
  45 /* @{
  46  * Register set setup.
  47  *
  48  * This should be done once at backend initializaion, as
  49  * ra_set_finalize is O(r^2*c^2).  The registers may be virtual
  50  * registers, such as aligned register pairs that conflict with the
  51  * two real registers from which they are composed.
  52  */
  53 struct ra_regs *ra_alloc_reg_set(void *mem_ctx, unsigned int count,
  54                                  bool need_conflict_lists);
  55 void ra_set_allocate_round_robin(struct ra_regs *regs);
  56 unsigned int ra_alloc_reg_class(struct ra_regs *regs);
  57 void ra_add_reg_conflict(struct ra_regs *regs,
  58                          unsigned int r1, unsigned int r2);
  59 void ra_add_transitive_reg_conflict(struct ra_regs *regs,
  60                                     unsigned int base_reg, unsigned int reg);
  61
  62 void
  63 ra_add_transitive_reg_pair_conflict(struct ra_regs *regs,
  64                                     unsigned int base_reg, unsigned int reg0, unsigned int reg1);
  65
  66 void ra_make_reg_conflicts_transitive(struct ra_regs *regs, unsigned int reg);
  67 void ra_class_add_reg(struct ra_regs *regs, unsigned int c, unsigned int reg);
  68 void ra_set_num_conflicts(struct ra_regs *regs, unsigned int class_a,
  69                           unsigned int class_b, unsigned int num_conflicts);
  70 void ra_set_finalize(struct ra_regs *regs, unsigned int **conflicts);
  71
  72 void ra_set_serialize(const struct ra_regs *regs, struct blob *blob);
  73 struct ra_regs *ra_set_deserialize(void *mem_ctx, struct blob_reader *blob);
  74 /** @} */
  75
  76 /** @{ Interference graph setup.
  77  *
  78  * Each interference graph node is a virtual variable in the IL.  It
  79  * is up to the user to ra_set_node_class() for the virtual variable,
  80  * and compute live ranges and ra_node_interfere() between conflicting
  81  * live ranges. Note that an interference *must not* be added between
  82  * two nodes if their classes haven't been assigned yet. The user
  83  * should set the class of each node before building the interference
  84  * graph.
  85  */
  86 struct ra_graph *ra_alloc_interference_graph(struct ra_regs *regs,
  87                                              unsigned int count);
  88 void ra_resize_interference_graph(struct ra_graph *g, unsigned int count);
  89 void ra_set_node_class(struct ra_graph *g, unsigned int n, unsigned int c);
  90 unsigned int ra_get_node_class(struct ra_graph *g, unsigned int n);
  91 unsigned int ra_add_node(struct ra_graph *g, unsigned int c);
  92
  93 /** @{ Register selection callback.
  94  *
  95  * The register allocator can use either one of two built-in register
  96  * selection behaviors (ie. lowest-available or round-robin), or the
  97  * user can implement it's own selection policy by setting an register
  98  * selection callback.  The parameters to the callback are:
  99  *
 100  *  - n       the graph node, ie. the virtual variable to select a
 101  *            register for
 102  *  - regs    bitset of available registers to choose; this bitset
 103  *            contains *all* registers, but registers of different
 104  *            classes will not have their corresponding bit set.
 105  *  - data    callback data specified in ra_set_select_reg_callback()
 106  */
 107 typedef unsigned int (*ra_select_reg_callback)(
 108       unsigned int n,        /* virtual variable to choose a physical reg for */
 109       BITSET_WORD *regs,     /* available physical regs to choose from */
 110       void *data);
 111
 112 void ra_set_select_reg_callback(struct ra_graph *g,
 113                                 ra_select_reg_callback callback,
 114                                 void *data);
 115 void ra_add_node_interference(struct ra_graph *g,
 116                               unsigned int n1, unsigned int n2);
 117 void ra_reset_node_interference(struct ra_graph *g, unsigned int n);
 118 /** @} */
 119
 120 /** @{ Graph-coloring register allocation */
 121 bool ra_allocate(struct ra_graph *g);
 122
 123 #define NO_REG ~0U
 124 /**
 125  * Returns NO_REG for a node that has not (yet) been assigned.
 126  */
 127 unsigned int ra_get_node_reg(struct ra_graph *g, unsigned int n);
 128 void ra_set_node_reg(struct ra_graph * g, unsigned int n, unsigned int reg);
 129 void ra_set_node_spill_cost(struct ra_graph *g, unsigned int n, float cost);
 130 int ra_get_best_spill_node(struct ra_graph *g);
 131 /** @} */
 132
 133
 134 #ifdef __cplusplus
 135 }  // extern "C"
 136 #endif
 137
 138 #endif /* REGISTER_ALLOCATE_H */